From d377c33c6e41270dbc3e42a011e09ae03a688b95 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:36:59 +0300
Subject: [PATCH 01/48] OV-52: - generatedText type

---
 .../src/bundles/open-ai/libs/types/generated-text.type.ts    | 5 -----
 1 file changed, 5 deletions(-)
 delete mode 100644 backend/src/bundles/open-ai/libs/types/generated-text.type.ts

diff --git a/backend/src/bundles/open-ai/libs/types/generated-text.type.ts b/backend/src/bundles/open-ai/libs/types/generated-text.type.ts
deleted file mode 100644
index 895720bf7..000000000
--- a/backend/src/bundles/open-ai/libs/types/generated-text.type.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-type GeneratedText = {
-    generatedText: string;
-};
-
-export { type GeneratedText };

From c369e9953541c18c8ec70d9591009b83df96db5d Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:38:09 +0300
Subject: [PATCH 02/48] OV-52: + enums

---
 shared/src/bundles/open-ai/enums/enums.ts                   | 3 +++
 shared/src/bundles/open-ai/enums/open-ai-path.enum.ts       | 5 +++++
 .../src/bundles/open-ai/enums/text-generation-rule.enum.ts  | 5 +++++
 .../enums/text-generation-validation-message.enum.ts        | 6 ++++++
 4 files changed, 19 insertions(+)
 create mode 100644 shared/src/bundles/open-ai/enums/enums.ts
 create mode 100644 shared/src/bundles/open-ai/enums/open-ai-path.enum.ts
 create mode 100644 shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts
 create mode 100644 shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts

diff --git a/shared/src/bundles/open-ai/enums/enums.ts b/shared/src/bundles/open-ai/enums/enums.ts
new file mode 100644
index 000000000..6d739d345
--- /dev/null
+++ b/shared/src/bundles/open-ai/enums/enums.ts
@@ -0,0 +1,3 @@
+export { OpenAIPath } from './open-ai-path.enum.js';
+export { TextGenerationValidationRule } from './text-generation-rule.enum.js';
+export { TextGenerationValidationMessage } from './text-generation-validation-message.enum.js';
diff --git a/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts b/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts
new file mode 100644
index 000000000..b9e7146df
--- /dev/null
+++ b/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts
@@ -0,0 +1,5 @@
+const OpenAIPath = {
+    ROOT: '/',
+} as const;
+
+export { OpenAIPath };
diff --git a/shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts b/shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts
new file mode 100644
index 000000000..da7c7fd17
--- /dev/null
+++ b/shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts
@@ -0,0 +1,5 @@
+const TextGenerationValidationRule = {
+    MESSAGE_MINIMUM_LENGTH: 6,
+} as const;
+
+export { TextGenerationValidationRule };
diff --git a/shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts b/shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts
new file mode 100644
index 000000000..9553c3e0f
--- /dev/null
+++ b/shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts
@@ -0,0 +1,6 @@
+const TextGenerationValidationMessage = {
+    MESSAGE_REQUIRED: 'User message is required',
+    MESSAGE_LENGTH: 'Message must have at least 6 characters',
+} as const;
+
+export { TextGenerationValidationMessage };

From 0a9de7a25188e0fb0e5c8fce2a31b0320303f1cb Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:39:27 +0300
Subject: [PATCH 03/48] OV-52: + HTTPMethod enum

---
 shared/src/framework/http/enums/enum.ts             | 1 +
 shared/src/framework/http/enums/http-method.enum.ts | 8 ++++++++
 shared/src/framework/http/http.ts                   | 2 +-
 3 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 shared/src/framework/http/enums/http-method.enum.ts

diff --git a/shared/src/framework/http/enums/enum.ts b/shared/src/framework/http/enums/enum.ts
index 2443406c8..0a49c8ff5 100644
--- a/shared/src/framework/http/enums/enum.ts
+++ b/shared/src/framework/http/enums/enum.ts
@@ -1,2 +1,3 @@
 export { HttpCode } from './http-code.enum.js';
 export { HttpHeader } from './http-header.enum.js';
+export { HTTPMethod } from './http-method.enum.js';
diff --git a/shared/src/framework/http/enums/http-method.enum.ts b/shared/src/framework/http/enums/http-method.enum.ts
new file mode 100644
index 000000000..39decc34d
--- /dev/null
+++ b/shared/src/framework/http/enums/http-method.enum.ts
@@ -0,0 +1,8 @@
+const HTTPMethod = {
+    DELETE: 'DELETE',
+    GET: 'GET',
+    POST: 'POST',
+    PUT: 'PUT',
+} as const;
+
+export { HTTPMethod };
diff --git a/shared/src/framework/http/http.ts b/shared/src/framework/http/http.ts
index 6bf40315c..dcfdc4cee 100644
--- a/shared/src/framework/http/http.ts
+++ b/shared/src/framework/http/http.ts
@@ -1,2 +1,2 @@
-export { HttpCode, HttpHeader } from './enums/enum.js';
+export { HttpCode, HttpHeader, HTTPMethod } from './enums/enum.js';
 export { type Http, type HttpMethod, type HttpOptions } from './types/types.js';

From 23bbba913d5897045b666cc7d318d65ed6a8f5e0 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:40:41 +0300
Subject: [PATCH 04/48] OV-52: * ApiPath enum

---
 shared/src/enums/api-path.enum.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/shared/src/enums/api-path.enum.ts b/shared/src/enums/api-path.enum.ts
index de8fc7b8d..43a92bb3a 100644
--- a/shared/src/enums/api-path.enum.ts
+++ b/shared/src/enums/api-path.enum.ts
@@ -1,6 +1,7 @@
 const ApiPath = {
     USERS: '/users',
     AUTH: '/auth',
+    OPEN_AI: '/openai',
 } as const;
 
 export { ApiPath };

From 60bb05c713b525970f0dfd468ad4141749dbd690 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:43:00 +0300
Subject: [PATCH 05/48] OV-52: + HTTPMethod enum

---
 backend/src/common/http/enums/enums.ts | 2 +-
 backend/src/common/http/http.ts        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/src/common/http/enums/enums.ts b/backend/src/common/http/enums/enums.ts
index 2e94a326e..94e1c540d 100644
--- a/backend/src/common/http/enums/enums.ts
+++ b/backend/src/common/http/enums/enums.ts
@@ -1 +1 @@
-export { HttpCode } from 'shared';
+export { HttpCode, HTTPMethod } from 'shared';
diff --git a/backend/src/common/http/http.ts b/backend/src/common/http/http.ts
index cc03c9476..90dd25ce9 100644
--- a/backend/src/common/http/http.ts
+++ b/backend/src/common/http/http.ts
@@ -1,3 +1,3 @@
-export { HttpCode } from './enums/enums.js';
+export { HttpCode, HTTPMethod } from './enums/enums.js';
 export { HttpError } from './exceptions/exceptions.js';
 export { type HttpMethod } from './types/types.js';

From 16b9285f0ecb946470e423d768bdf71634fbb0c5 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 15:44:26 +0300
Subject: [PATCH 06/48] OV-52: + GenerateTextRequestDto type

---
 .../src/bundles/open-ai/types/generate-text-request-dto.ts   | 5 +++++
 shared/src/bundles/open-ai/types/types.ts                    | 1 +
 2 files changed, 6 insertions(+)
 create mode 100644 shared/src/bundles/open-ai/types/generate-text-request-dto.ts
 create mode 100644 shared/src/bundles/open-ai/types/types.ts

diff --git a/shared/src/bundles/open-ai/types/generate-text-request-dto.ts b/shared/src/bundles/open-ai/types/generate-text-request-dto.ts
new file mode 100644
index 000000000..fda54b53b
--- /dev/null
+++ b/shared/src/bundles/open-ai/types/generate-text-request-dto.ts
@@ -0,0 +1,5 @@
+type GenerateTextRequestDto = {
+    message: string;
+};
+
+export { type GenerateTextRequestDto };
diff --git a/shared/src/bundles/open-ai/types/types.ts b/shared/src/bundles/open-ai/types/types.ts
new file mode 100644
index 000000000..2fee7e222
--- /dev/null
+++ b/shared/src/bundles/open-ai/types/types.ts
@@ -0,0 +1 @@
+export { type GenerateTextRequestDto } from './generate-text-request-dto.js';

From fd75b00c518412af7fccaecd710c5dffdbe54c22 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 16:16:18 +0300
Subject: [PATCH 07/48] OV-52: + validation schema

---
 .../generate-text.validation-schema.ts        | 26 +++++++++++++++++++
 .../validation-schemas/validation-schemas.ts  |  1 +
 2 files changed, 27 insertions(+)
 create mode 100644 shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts
 create mode 100644 shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts

diff --git a/shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts b/shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts
new file mode 100644
index 000000000..c80148070
--- /dev/null
+++ b/shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts
@@ -0,0 +1,26 @@
+import { z } from 'zod';
+
+import {
+    TextGenerationValidationMessage,
+    TextGenerationValidationRule,
+} from '../enums/enums.js';
+
+type GenerateTextRequestValidationDto = {
+    message: z.ZodString;
+};
+
+const textGeneration = z
+    .object<GenerateTextRequestValidationDto>({
+        message: z
+            .string({
+                required_error:
+                    TextGenerationValidationMessage.MESSAGE_REQUIRED,
+            })
+            .trim()
+            .min(TextGenerationValidationRule.MESSAGE_MINIMUM_LENGTH, {
+                message: TextGenerationValidationMessage.MESSAGE_LENGTH,
+            }),
+    })
+    .required();
+
+export { textGeneration };
diff --git a/shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts b/shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts
new file mode 100644
index 000000000..28665f967
--- /dev/null
+++ b/shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts
@@ -0,0 +1 @@
+export { textGeneration } from './generate-text.validation-schema.js';

From a9b71987633324f62ee637aaa7e1dc9c517028ed Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 16:59:48 +0300
Subject: [PATCH 08/48] OV-52: * rename file

---
 shared/src/bundles/chat/chat.ts                              | 3 +++
 shared/src/bundles/chat/enums/chat.enum.ts                   | 5 +++++
 shared/src/bundles/{open-ai => chat}/enums/enums.ts          | 2 +-
 .../{open-ai => chat}/enums/text-generation-rule.enum.ts     | 0
 .../enums/text-generation-validation-message.enum.ts         | 0
 .../{open-ai => chat}/types/generate-text-request-dto.ts     | 0
 shared/src/bundles/{open-ai => chat}/types/types.ts          | 0
 .../validation-schemas/generate-text.validation-schema.ts    | 0
 .../validation-schemas/validation-schemas.ts                 | 0
 shared/src/bundles/open-ai/enums/open-ai-path.enum.ts        | 5 -----
 10 files changed, 9 insertions(+), 6 deletions(-)
 create mode 100644 shared/src/bundles/chat/chat.ts
 create mode 100644 shared/src/bundles/chat/enums/chat.enum.ts
 rename shared/src/bundles/{open-ai => chat}/enums/enums.ts (76%)
 rename shared/src/bundles/{open-ai => chat}/enums/text-generation-rule.enum.ts (100%)
 rename shared/src/bundles/{open-ai => chat}/enums/text-generation-validation-message.enum.ts (100%)
 rename shared/src/bundles/{open-ai => chat}/types/generate-text-request-dto.ts (100%)
 rename shared/src/bundles/{open-ai => chat}/types/types.ts (100%)
 rename shared/src/bundles/{open-ai => chat}/validation-schemas/generate-text.validation-schema.ts (100%)
 rename shared/src/bundles/{open-ai => chat}/validation-schemas/validation-schemas.ts (100%)
 delete mode 100644 shared/src/bundles/open-ai/enums/open-ai-path.enum.ts

diff --git a/shared/src/bundles/chat/chat.ts b/shared/src/bundles/chat/chat.ts
new file mode 100644
index 000000000..8aaa42161
--- /dev/null
+++ b/shared/src/bundles/chat/chat.ts
@@ -0,0 +1,3 @@
+export { ChatPath } from './enums/enums.js';
+export { type GenerateTextRequestDto } from './types/types.js';
+export { textGeneration as textGenerationValidationSchema } from './validation-schemas/validation-schemas.js';
diff --git a/shared/src/bundles/chat/enums/chat.enum.ts b/shared/src/bundles/chat/enums/chat.enum.ts
new file mode 100644
index 000000000..5580c6237
--- /dev/null
+++ b/shared/src/bundles/chat/enums/chat.enum.ts
@@ -0,0 +1,5 @@
+const ChatPath = {
+    ROOT: '/',
+} as const;
+
+export { ChatPath };
diff --git a/shared/src/bundles/open-ai/enums/enums.ts b/shared/src/bundles/chat/enums/enums.ts
similarity index 76%
rename from shared/src/bundles/open-ai/enums/enums.ts
rename to shared/src/bundles/chat/enums/enums.ts
index 6d739d345..a70bbdbd4 100644
--- a/shared/src/bundles/open-ai/enums/enums.ts
+++ b/shared/src/bundles/chat/enums/enums.ts
@@ -1,3 +1,3 @@
-export { OpenAIPath } from './open-ai-path.enum.js';
+export { ChatPath } from './chat.enum.js';
 export { TextGenerationValidationRule } from './text-generation-rule.enum.js';
 export { TextGenerationValidationMessage } from './text-generation-validation-message.enum.js';
diff --git a/shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts b/shared/src/bundles/chat/enums/text-generation-rule.enum.ts
similarity index 100%
rename from shared/src/bundles/open-ai/enums/text-generation-rule.enum.ts
rename to shared/src/bundles/chat/enums/text-generation-rule.enum.ts
diff --git a/shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts b/shared/src/bundles/chat/enums/text-generation-validation-message.enum.ts
similarity index 100%
rename from shared/src/bundles/open-ai/enums/text-generation-validation-message.enum.ts
rename to shared/src/bundles/chat/enums/text-generation-validation-message.enum.ts
diff --git a/shared/src/bundles/open-ai/types/generate-text-request-dto.ts b/shared/src/bundles/chat/types/generate-text-request-dto.ts
similarity index 100%
rename from shared/src/bundles/open-ai/types/generate-text-request-dto.ts
rename to shared/src/bundles/chat/types/generate-text-request-dto.ts
diff --git a/shared/src/bundles/open-ai/types/types.ts b/shared/src/bundles/chat/types/types.ts
similarity index 100%
rename from shared/src/bundles/open-ai/types/types.ts
rename to shared/src/bundles/chat/types/types.ts
diff --git a/shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts b/shared/src/bundles/chat/validation-schemas/generate-text.validation-schema.ts
similarity index 100%
rename from shared/src/bundles/open-ai/validation-schemas/generate-text.validation-schema.ts
rename to shared/src/bundles/chat/validation-schemas/generate-text.validation-schema.ts
diff --git a/shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts b/shared/src/bundles/chat/validation-schemas/validation-schemas.ts
similarity index 100%
rename from shared/src/bundles/open-ai/validation-schemas/validation-schemas.ts
rename to shared/src/bundles/chat/validation-schemas/validation-schemas.ts
diff --git a/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts b/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts
deleted file mode 100644
index b9e7146df..000000000
--- a/shared/src/bundles/open-ai/enums/open-ai-path.enum.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-const OpenAIPath = {
-    ROOT: '/',
-} as const;
-
-export { OpenAIPath };

From 9dc16e6338d641339a98bf14a0a26d7e73fe8a0d Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:00:54 +0300
Subject: [PATCH 09/48] OV-52: * rename endpoint

---
 shared/src/enums/api-path.enum.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/shared/src/enums/api-path.enum.ts b/shared/src/enums/api-path.enum.ts
index 43a92bb3a..63f0bbc02 100644
--- a/shared/src/enums/api-path.enum.ts
+++ b/shared/src/enums/api-path.enum.ts
@@ -1,7 +1,7 @@
 const ApiPath = {
     USERS: '/users',
     AUTH: '/auth',
-    OPEN_AI: '/openai',
+    CHAT: '/chat',
 } as const;
 
 export { ApiPath };

From 23fd9b3357a7bd1ca90118aeec7ed71781ca9a47 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:01:51 +0300
Subject: [PATCH 10/48] OV-52: + shared exports

---
 shared/src/index.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/shared/src/index.ts b/shared/src/index.ts
index d4b77ee0e..40647ed47 100644
--- a/shared/src/index.ts
+++ b/shared/src/index.ts
@@ -1,4 +1,9 @@
 export { AuthApiPath } from './bundles/auth/auth.js';
+export {
+    type GenerateTextRequestDto,
+    ChatPath,
+    textGenerationValidationSchema,
+} from './bundles/chat/chat.js';
 export {
     type UserGetAllItemResponseDto,
     type UserGetAllResponseDto,
@@ -29,6 +34,7 @@ export {
     type HttpOptions,
     HttpCode,
     HttpHeader,
+    HTTPMethod,
 } from './framework/http/http.js';
 export { type Storage } from './framework/storage/storage.js';
 export { configureString } from './helpers/helpers.js';

From 2cdc71840d7f5ba01a01d3a2727c3f54153f3e9f Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:03:37 +0300
Subject: [PATCH 11/48] OV-52: + session key

---
 backend/src/common/config/base-config.package.ts           | 6 ++++++
 backend/src/common/config/types/environment-schema.type.ts | 1 +
 2 files changed, 7 insertions(+)

diff --git a/backend/src/common/config/base-config.package.ts b/backend/src/common/config/base-config.package.ts
index ef47737b3..bb1ba32fd 100644
--- a/backend/src/common/config/base-config.package.ts
+++ b/backend/src/common/config/base-config.package.ts
@@ -47,6 +47,12 @@ class BaseConfig implements Config {
                     env: 'OPEN_AI_KEY',
                     default: null,
                 },
+                SESSION_KEY: {
+                    doc: 'Key for sessions',
+                    format: String,
+                    env: 'SESSION_KEY',
+                    default: null,
+                },
             },
             DB: {
                 CONNECTION_STRING: {
diff --git a/backend/src/common/config/types/environment-schema.type.ts b/backend/src/common/config/types/environment-schema.type.ts
index ce22834aa..60348afe5 100644
--- a/backend/src/common/config/types/environment-schema.type.ts
+++ b/backend/src/common/config/types/environment-schema.type.ts
@@ -6,6 +6,7 @@ type EnvironmentSchema = {
         PORT: number;
         ENVIRONMENT: ValueOf<typeof AppEnvironment>;
         OPEN_AI_KEY: string;
+        SESSION_KEY: string;
     };
     DB: {
         CONNECTION_STRING: string;

From da455ab7aaabb3560afcdae1504d93143c9e3a1a Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:04:56 +0300
Subject: [PATCH 12/48] OV-52: + fastify session library

---
 backend/package.json |  2 ++
 package-lock.json    | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/backend/package.json b/backend/package.json
index 3e19ba323..6dcde8fac 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -27,6 +27,8 @@
         "tsx": "4.17.0"
     },
     "dependencies": {
+        "@fastify/cookie": "9.4.0",
+        "@fastify/session": "10.9.0",
         "@fastify/static": "7.0.4",
         "@fastify/swagger": "8.15.0",
         "@fastify/swagger-ui": "4.0.1",
diff --git a/package-lock.json b/package-lock.json
index 828e43422..1959c3d2e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -39,6 +39,8 @@
         },
         "backend": {
             "dependencies": {
+                "@fastify/cookie": "9.4.0",
+                "@fastify/session": "10.9.0",
                 "@fastify/static": "7.0.4",
                 "@fastify/swagger": "8.15.0",
                 "@fastify/swagger-ui": "4.0.1",
@@ -2691,6 +2693,15 @@
             "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-2.4.0.tgz",
             "integrity": "sha512-ypuAmmMKInk5q7XcepxlnUWDLWv4GFtaJqAzWKqn62IpQ3pejtr5dTVbt3vwqVaMKmkNR55sTT+CqUKIaT21BA=="
         },
+        "node_modules/@fastify/cookie": {
+            "version": "9.4.0",
+            "resolved": "https://registry.npmjs.org/@fastify/cookie/-/cookie-9.4.0.tgz",
+            "integrity": "sha512-Th+pt3kEkh4MQD/Q2q1bMuJIB5NX/D5SwSpOKu3G/tjoGbwfpurIMJsWSPS0SJJ4eyjtmQ8OipDQspf8RbUOlg==",
+            "dependencies": {
+                "cookie-signature": "^1.1.0",
+                "fastify-plugin": "^4.0.0"
+            }
+        },
         "node_modules/@fastify/error": {
             "version": "3.4.1",
             "resolved": "https://registry.npmjs.org/@fastify/error/-/error-3.4.1.tgz",
@@ -2724,6 +2735,15 @@
                 "mime": "^3.0.0"
             }
         },
+        "node_modules/@fastify/session": {
+            "version": "10.9.0",
+            "resolved": "https://registry.npmjs.org/@fastify/session/-/session-10.9.0.tgz",
+            "integrity": "sha512-u/c42RuAaxCeEuRCAwK2+/SfGqKOd0NSyRzEvDwFBWySQoKUZQyb9OmmJSWJBbOP1OfaU2OsDrjbPbghE1l/YQ==",
+            "dependencies": {
+                "fastify-plugin": "^4.0.0",
+                "safe-stable-stringify": "^2.3.1"
+            }
+        },
         "node_modules/@fastify/static": {
             "version": "7.0.4",
             "resolved": "https://registry.npmjs.org/@fastify/static/-/static-7.0.4.tgz",
@@ -5259,6 +5279,14 @@
                 "node": ">= 0.6"
             }
         },
+        "node_modules/cookie-signature": {
+            "version": "1.2.1",
+            "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.2.1.tgz",
+            "integrity": "sha512-78KWk9T26NhzXtuL26cIJ8/qNHANyJ/ZYrmEXFzUmhZdjpBv+DlWlOANRTGBt48YcyslsLrj0bMLFTmXvLRCOw==",
+            "engines": {
+                "node": ">=6.6.0"
+            }
+        },
         "node_modules/copy-to-clipboard": {
             "version": "3.3.3",
             "resolved": "https://registry.npmjs.org/copy-to-clipboard/-/copy-to-clipboard-3.3.3.tgz",

From 0dcbe1cd3fc6de8b86687e2f164bc75c30ad19d7 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:06:28 +0300
Subject: [PATCH 13/48] OV-52: + types

---
 .../src/bundles/chat/libs/types/message.type.ts   | 10 ++++++++++
 .../chat/libs/types/open-ai-service.type.ts       | 15 +++++++++++++++
 backend/src/bundles/chat/libs/types/types.ts      |  4 ++++
 3 files changed, 29 insertions(+)
 create mode 100644 backend/src/bundles/chat/libs/types/message.type.ts
 create mode 100644 backend/src/bundles/chat/libs/types/open-ai-service.type.ts
 create mode 100644 backend/src/bundles/chat/libs/types/types.ts

diff --git a/backend/src/bundles/chat/libs/types/message.type.ts b/backend/src/bundles/chat/libs/types/message.type.ts
new file mode 100644
index 000000000..1bd4ee658
--- /dev/null
+++ b/backend/src/bundles/chat/libs/types/message.type.ts
@@ -0,0 +1,10 @@
+import { type ValueOf } from 'shared';
+
+import { type OpenAIRole } from '../enums/enums.js';
+
+type Message = {
+    role: ValueOf<typeof OpenAIRole>;
+    content: string;
+};
+
+export { type Message };
diff --git a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
new file mode 100644
index 000000000..e988d31bf
--- /dev/null
+++ b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
@@ -0,0 +1,15 @@
+import { type ValueOf } from 'shared';
+
+import { type OpenAIRole } from '../enums/enums.js';
+import { type Message } from './message.type.js';
+
+type OpenAIService = {
+    generateText(messages: Message[]): Promise<string>;
+    addMessageToHistory(
+        chatHistory: Message[],
+        userMessage: string,
+        role: ValueOf<typeof OpenAIRole>,
+    ): void;
+};
+
+export { type OpenAIService };
diff --git a/backend/src/bundles/chat/libs/types/types.ts b/backend/src/bundles/chat/libs/types/types.ts
new file mode 100644
index 000000000..92b6f0cbc
--- /dev/null
+++ b/backend/src/bundles/chat/libs/types/types.ts
@@ -0,0 +1,4 @@
+export { type Message } from './message.type.js';
+export { type OpenAIService } from './open-ai-service.type.js';
+export { type SessionChatHistory } from './session-chat-history.js';
+export { type GenerateTextRequestDto } from 'shared';

From 31e7bdca876fe1e3a49c865ac6a09ec229b0591c Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:08:42 +0300
Subject: [PATCH 14/48] OV-52: + libs

---
 .../{open-ai => chat}/libs/constants/chat-model.constant.ts      | 0
 .../src/bundles/{open-ai => chat}/libs/constants/constants.ts    | 0
 .../{open-ai => chat}/libs/constants/max-token.constant.ts       | 0
 backend/src/bundles/{open-ai => chat}/libs/enums/enums.ts        | 1 +
 .../bundles/{open-ai => chat}/libs/enums/open-ai-role.enum.ts    | 0
 5 files changed, 1 insertion(+)
 rename backend/src/bundles/{open-ai => chat}/libs/constants/chat-model.constant.ts (100%)
 rename backend/src/bundles/{open-ai => chat}/libs/constants/constants.ts (100%)
 rename backend/src/bundles/{open-ai => chat}/libs/constants/max-token.constant.ts (100%)
 rename backend/src/bundles/{open-ai => chat}/libs/enums/enums.ts (60%)
 rename backend/src/bundles/{open-ai => chat}/libs/enums/open-ai-role.enum.ts (100%)

diff --git a/backend/src/bundles/open-ai/libs/constants/chat-model.constant.ts b/backend/src/bundles/chat/libs/constants/chat-model.constant.ts
similarity index 100%
rename from backend/src/bundles/open-ai/libs/constants/chat-model.constant.ts
rename to backend/src/bundles/chat/libs/constants/chat-model.constant.ts
diff --git a/backend/src/bundles/open-ai/libs/constants/constants.ts b/backend/src/bundles/chat/libs/constants/constants.ts
similarity index 100%
rename from backend/src/bundles/open-ai/libs/constants/constants.ts
rename to backend/src/bundles/chat/libs/constants/constants.ts
diff --git a/backend/src/bundles/open-ai/libs/constants/max-token.constant.ts b/backend/src/bundles/chat/libs/constants/max-token.constant.ts
similarity index 100%
rename from backend/src/bundles/open-ai/libs/constants/max-token.constant.ts
rename to backend/src/bundles/chat/libs/constants/max-token.constant.ts
diff --git a/backend/src/bundles/open-ai/libs/enums/enums.ts b/backend/src/bundles/chat/libs/enums/enums.ts
similarity index 60%
rename from backend/src/bundles/open-ai/libs/enums/enums.ts
rename to backend/src/bundles/chat/libs/enums/enums.ts
index 58dc0594a..b111ba763 100644
--- a/backend/src/bundles/open-ai/libs/enums/enums.ts
+++ b/backend/src/bundles/chat/libs/enums/enums.ts
@@ -1 +1,2 @@
 export { OpenAIRole } from './open-ai-role.enum.js';
+export { ChatPath } from 'shared';
diff --git a/backend/src/bundles/open-ai/libs/enums/open-ai-role.enum.ts b/backend/src/bundles/chat/libs/enums/open-ai-role.enum.ts
similarity index 100%
rename from backend/src/bundles/open-ai/libs/enums/open-ai-role.enum.ts
rename to backend/src/bundles/chat/libs/enums/open-ai-role.enum.ts

From fbd2dffa69de9b1b66a3dcf527235f2e4f2b7bff Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:11:52 +0300
Subject: [PATCH 15/48] OV-52: + libs

---
 .../src/bundles/chat/libs/types/session-chat-history.ts    | 7 +++++++
 .../chat/libs/validation-schemas/validation-schemas.ts     | 1 +
 .../common/controller/types/api-handler-options.type.ts    | 2 ++
 .../src/common/plugins/libs/enums/controller-hook.enum.ts  | 5 +++++
 backend/src/common/plugins/libs/enums/enums.ts             | 1 +
 5 files changed, 16 insertions(+)
 create mode 100644 backend/src/bundles/chat/libs/types/session-chat-history.ts
 create mode 100644 backend/src/bundles/chat/libs/validation-schemas/validation-schemas.ts
 create mode 100644 backend/src/common/plugins/libs/enums/controller-hook.enum.ts
 create mode 100644 backend/src/common/plugins/libs/enums/enums.ts

diff --git a/backend/src/bundles/chat/libs/types/session-chat-history.ts b/backend/src/bundles/chat/libs/types/session-chat-history.ts
new file mode 100644
index 000000000..02ce4a1a0
--- /dev/null
+++ b/backend/src/bundles/chat/libs/types/session-chat-history.ts
@@ -0,0 +1,7 @@
+import { type Message } from './message.type.js';
+
+type SessionChatHistory = {
+    chatHistory: Message[];
+};
+
+export { type SessionChatHistory };
diff --git a/backend/src/bundles/chat/libs/validation-schemas/validation-schemas.ts b/backend/src/bundles/chat/libs/validation-schemas/validation-schemas.ts
new file mode 100644
index 000000000..b7a3ade52
--- /dev/null
+++ b/backend/src/bundles/chat/libs/validation-schemas/validation-schemas.ts
@@ -0,0 +1 @@
+export { textGenerationValidationSchema } from 'shared';
diff --git a/backend/src/common/controller/types/api-handler-options.type.ts b/backend/src/common/controller/types/api-handler-options.type.ts
index fd38e4503..8514b84a0 100644
--- a/backend/src/common/controller/types/api-handler-options.type.ts
+++ b/backend/src/common/controller/types/api-handler-options.type.ts
@@ -2,6 +2,7 @@ type DefaultApiHandlerOptions = {
     body?: unknown;
     query?: unknown;
     params?: unknown;
+    session?: unknown;
 };
 
 type ApiHandlerOptions<
@@ -10,6 +11,7 @@ type ApiHandlerOptions<
     body: T['body'];
     query: T['query'];
     params: T['params'];
+    session: T['session'];
 };
 
 export { type ApiHandlerOptions };
diff --git a/backend/src/common/plugins/libs/enums/controller-hook.enum.ts b/backend/src/common/plugins/libs/enums/controller-hook.enum.ts
new file mode 100644
index 000000000..d3541a9a8
--- /dev/null
+++ b/backend/src/common/plugins/libs/enums/controller-hook.enum.ts
@@ -0,0 +1,5 @@
+const ControllerHook = {
+    ON_REQUEST: 'onRequest',
+} as const;
+
+export { ControllerHook };
diff --git a/backend/src/common/plugins/libs/enums/enums.ts b/backend/src/common/plugins/libs/enums/enums.ts
new file mode 100644
index 000000000..24e279ff4
--- /dev/null
+++ b/backend/src/common/plugins/libs/enums/enums.ts
@@ -0,0 +1 @@
+export { ControllerHook } from './controller-hook.enum.js';

From dbe2dfbf5d054641f2bbde6b2f54179f3f4d0eb1 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:13:49 +0300
Subject: [PATCH 16/48] OV-52: + plugin

---
 .../controller/base-controller.package.ts     |  3 +-
 backend/src/common/plugins/plugins.ts         |  1 +
 .../common/plugins/session/session.plugin.ts  | 31 +++++++++++++++++++
 .../server-application/base-server-app.ts     | 11 +++++++
 4 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 backend/src/common/plugins/plugins.ts
 create mode 100644 backend/src/common/plugins/session/session.plugin.ts

diff --git a/backend/src/common/controller/base-controller.package.ts b/backend/src/common/controller/base-controller.package.ts
index aa2f0fc8e..a481b972a 100644
--- a/backend/src/common/controller/base-controller.package.ts
+++ b/backend/src/common/controller/base-controller.package.ts
@@ -49,12 +49,13 @@ class BaseController implements Controller {
     private mapRequest(
         request: Parameters<ServerAppRouteParameters['handler']>[0],
     ): ApiHandlerOptions {
-        const { body, query, params } = request;
+        const { body, query, params, session } = request;
 
         return {
             body,
             query,
             params,
+            session,
         };
     }
 }
diff --git a/backend/src/common/plugins/plugins.ts b/backend/src/common/plugins/plugins.ts
new file mode 100644
index 000000000..262690612
--- /dev/null
+++ b/backend/src/common/plugins/plugins.ts
@@ -0,0 +1 @@
+export { session } from './session/session.plugin.js';
diff --git a/backend/src/common/plugins/session/session.plugin.ts b/backend/src/common/plugins/session/session.plugin.ts
new file mode 100644
index 000000000..047a7376e
--- /dev/null
+++ b/backend/src/common/plugins/session/session.plugin.ts
@@ -0,0 +1,31 @@
+import fastifyCookie from '@fastify/cookie';
+import fastifySession from '@fastify/session';
+import fp from 'fastify-plugin';
+
+import { type BaseConfig } from '~/common/config/base-config.package.js';
+
+import { ControllerHook } from '../libs/enums/enums.js';
+
+type Options = {
+    services: {
+        config: BaseConfig;
+    };
+};
+
+const session = fp<Options>(async (fastify, { services }) => {
+    await fastify.register(fastifyCookie);
+    await fastify.register(fastifySession, {
+        secret: services.config.ENV.APP.SESSION_KEY,
+        cookie: { secure: false },
+    });
+
+    fastify.addHook(ControllerHook.ON_REQUEST, (request, _replay, done) => {
+        if (!request.session.chatHistory) {
+            request.session.chatHistory = [];
+        }
+
+        done();
+    });
+});
+
+export { session };
diff --git a/backend/src/common/server-application/base-server-app.ts b/backend/src/common/server-application/base-server-app.ts
index 25cef068b..a2bbca2bb 100644
--- a/backend/src/common/server-application/base-server-app.ts
+++ b/backend/src/common/server-application/base-server-app.ts
@@ -22,6 +22,7 @@ import {
     type ValidationSchema,
 } from '~/common/types/types.js';
 
+import { session } from '../plugins/plugins.js';
 import {
     type ServerApp,
     type ServerAppApi,
@@ -122,6 +123,14 @@ class BaseServerApp implements ServerApp {
         );
     }
 
+    private registerPlugins(): void {
+        this.app.register(session, {
+            services: {
+                config: this.config,
+            },
+        });
+    }
+
     private initValidationCompiler(): void {
         this.app.setValidatorCompiler(
             ({ schema }: { schema: ValidationSchema }) => {
@@ -200,6 +209,8 @@ class BaseServerApp implements ServerApp {
 
         await this.initMiddlewares();
 
+        this.registerPlugins();
+
         this.initValidationCompiler();
 
         this.initErrorHandler();

From e69ce2a463df7a35bf4cc9f17eab72c9abb8980a Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:14:58 +0300
Subject: [PATCH 17/48] OV-52: + open ai service

---
 .../{open-ai => chat}/open-ai.service.ts      | 27 ++++++++++++-------
 .../open-ai/libs/types/message.type.ts        | 10 -------
 .../libs/types/open-ai-service.type.ts        |  8 ------
 .../src/bundles/open-ai/libs/types/types.ts   |  3 ---
 4 files changed, 18 insertions(+), 30 deletions(-)
 rename backend/src/bundles/{open-ai => chat}/open-ai.service.ts (59%)
 delete mode 100644 backend/src/bundles/open-ai/libs/types/message.type.ts
 delete mode 100644 backend/src/bundles/open-ai/libs/types/open-ai-service.type.ts
 delete mode 100644 backend/src/bundles/open-ai/libs/types/types.ts

diff --git a/backend/src/bundles/open-ai/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
similarity index 59%
rename from backend/src/bundles/open-ai/open-ai.service.ts
rename to backend/src/bundles/chat/open-ai.service.ts
index b89b0e179..d04d927d4 100644
--- a/backend/src/bundles/open-ai/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -1,23 +1,20 @@
 import OpenAI, { type OpenAI as OpenAIType } from 'openai';
+import { type ValueOf } from 'shared';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
 
 import { CHAT_MODEL, MAX_TOKEN } from './libs/constants/constants.js';
+import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
 import {
-    type GeneratedText,
     type Message,
     type OpenAIService as OpenAIServiceModule,
 } from './libs/types/types.js';
 
-type Constructor = {
-    config: BaseConfig;
-};
-
 class OpenAIService implements OpenAIServiceModule {
     private config: BaseConfig;
     private openAi: OpenAIType;
 
-    public constructor({ config }: Constructor) {
+    public constructor(config: BaseConfig) {
         this.config = config;
         this.openAi = this.initOpenAi();
     }
@@ -28,15 +25,27 @@ class OpenAIService implements OpenAIServiceModule {
         });
     };
 
-    public async generateText(messages: Message[]): Promise<GeneratedText> {
+    public addMessageToHistory(
+        chatHistory: Message[],
+        userMessage: string,
+        role: ValueOf<typeof OpenAIRole>,
+    ): void {
+        const newUserMessage = {
+            content: userMessage,
+            role,
+        };
+
+        chatHistory.push(newUserMessage);
+    }
+
+    public async generateText(messages: Message[]): Promise<string> {
         const completion = await this.openAi.chat.completions.create({
             messages,
             model: CHAT_MODEL,
             max_tokens: MAX_TOKEN,
         });
 
-        const generatedText = completion.choices[0]?.message.content || '';
-        return { generatedText };
+        return completion.choices[0]?.message.content || '';
     }
 }
 
diff --git a/backend/src/bundles/open-ai/libs/types/message.type.ts b/backend/src/bundles/open-ai/libs/types/message.type.ts
deleted file mode 100644
index 1bd4ee658..000000000
--- a/backend/src/bundles/open-ai/libs/types/message.type.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import { type ValueOf } from 'shared';
-
-import { type OpenAIRole } from '../enums/enums.js';
-
-type Message = {
-    role: ValueOf<typeof OpenAIRole>;
-    content: string;
-};
-
-export { type Message };
diff --git a/backend/src/bundles/open-ai/libs/types/open-ai-service.type.ts b/backend/src/bundles/open-ai/libs/types/open-ai-service.type.ts
deleted file mode 100644
index 313148017..000000000
--- a/backend/src/bundles/open-ai/libs/types/open-ai-service.type.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-import { type GeneratedText } from './generated-text.type.js';
-import { type Message } from './message.type.js';
-
-type OpenAIService = {
-    generateText(messages: Message[]): Promise<GeneratedText>;
-};
-
-export { type OpenAIService };
diff --git a/backend/src/bundles/open-ai/libs/types/types.ts b/backend/src/bundles/open-ai/libs/types/types.ts
deleted file mode 100644
index d3de0182b..000000000
--- a/backend/src/bundles/open-ai/libs/types/types.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export { type GeneratedText } from './generated-text.type.js';
-export { type Message } from './message.type.js';
-export { type OpenAIService } from './open-ai-service.type.js';

From 61e42d4e210b2536ed16685770364d6397048528 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:15:54 +0300
Subject: [PATCH 18/48] OV-52: + chat controller

---
 backend/src/bundles/chat/chat.controller.ts   | 73 +++++++++++++++++++
 backend/src/bundles/chat/chat.ts              | 10 +++
 .../server-application/server-application.ts  |  2 +
 3 files changed, 85 insertions(+)
 create mode 100644 backend/src/bundles/chat/chat.controller.ts
 create mode 100644 backend/src/bundles/chat/chat.ts

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
new file mode 100644
index 000000000..a774afb8c
--- /dev/null
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -0,0 +1,73 @@
+import {
+    type ApiHandlerOptions,
+    type ApiHandlerResponse,
+    BaseController,
+} from '~/common/controller/controller.js';
+import { ApiPath } from '~/common/enums/enums.js';
+import { HttpCode, HTTPMethod } from '~/common/http/http.js';
+import { type Logger } from '~/common/logger/logger.js';
+
+import { ChatPath, OpenAIRole } from './libs/enums/enums.js';
+import {
+    type GenerateTextRequestDto,
+    type SessionChatHistory,
+} from './libs/types/types.js';
+import { textGenerationValidationSchema } from './libs/validation-schemas/validation-schemas.js';
+import { type OpenAIService } from './open-ai.service.js';
+
+class ChatController extends BaseController {
+    private openAIService: OpenAIService;
+
+    public constructor(logger: Logger, openAIService: OpenAIService) {
+        super(logger, ApiPath.CHAT);
+
+        this.openAIService = openAIService;
+
+        this.addRoute({
+            path: ChatPath.ROOT,
+            method: HTTPMethod.POST,
+            validation: {
+                body: textGenerationValidationSchema,
+            },
+            handler: (options) =>
+                this.generateChatAnswer(
+                    options as ApiHandlerOptions<{
+                        body: GenerateTextRequestDto;
+                        session: SessionChatHistory;
+                    }>,
+                ),
+        });
+    }
+
+    private async generateChatAnswer(
+        options: ApiHandlerOptions<{
+            body: GenerateTextRequestDto;
+            session: SessionChatHistory;
+        }>,
+    ): Promise<ApiHandlerResponse> {
+        const { body, session } = options;
+
+        this.openAIService.addMessageToHistory(
+            session.chatHistory,
+            body.message,
+            OpenAIRole.USER,
+        );
+
+        const generatedText = await this.openAIService.generateText(
+            session.chatHistory,
+        );
+
+        this.openAIService.addMessageToHistory(
+            session.chatHistory,
+            generatedText,
+            OpenAIRole.ASSISTANT,
+        );
+
+        return {
+            payload: generatedText,
+            status: HttpCode.OK,
+        };
+    }
+}
+
+export { ChatController };
diff --git a/backend/src/bundles/chat/chat.ts b/backend/src/bundles/chat/chat.ts
new file mode 100644
index 000000000..a77b520d5
--- /dev/null
+++ b/backend/src/bundles/chat/chat.ts
@@ -0,0 +1,10 @@
+import { config } from '~/common/config/config.js';
+import { logger } from '~/common/logger/logger.js';
+
+import { ChatController } from './chat.controller.js';
+import { OpenAIService } from './open-ai.service.js';
+
+const openAIService = new OpenAIService(config);
+const chatController = new ChatController(logger, openAIService);
+
+export { chatController };
diff --git a/backend/src/common/server-application/server-application.ts b/backend/src/common/server-application/server-application.ts
index c8c4a88f9..ea5ee7bdf 100644
--- a/backend/src/common/server-application/server-application.ts
+++ b/backend/src/common/server-application/server-application.ts
@@ -1,4 +1,5 @@
 import { authController } from '~/bundles/auth/auth.js';
+import { chatController } from '~/bundles/chat/chat.js';
 import { userController } from '~/bundles/users/users.js';
 import { config } from '~/common/config/config.js';
 import { database } from '~/common/database/database.js';
@@ -12,6 +13,7 @@ const apiV1 = new BaseServerAppApi(
     config,
     ...authController.routes,
     ...userController.routes,
+    ...chatController.routes,
 );
 const serverApp = new BaseServerApp({
     config,

From f4a1e587bd7b6487b842ebc526253ddf7fe54ec0 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Fri, 23 Aug 2024 17:16:39 +0300
Subject: [PATCH 19/48] OV-52: + fastify module

---
 backend/src/packages.d.ts | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 backend/src/packages.d.ts

diff --git a/backend/src/packages.d.ts b/backend/src/packages.d.ts
new file mode 100644
index 000000000..335271c16
--- /dev/null
+++ b/backend/src/packages.d.ts
@@ -0,0 +1,7 @@
+import { type Message } from './bundles/chat/libs/types/types.ts';
+
+declare module 'fastify' {
+    interface Session {
+        chatHistory: Message[];
+    }
+}

From 7b3c9623987d13b6d31a3fe22287fe363c6a3fbc Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 00:38:41 +0300
Subject: [PATCH 20/48] OV-52: * HttpMethod type

---
 shared/src/framework/http/types/http-method.type.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/shared/src/framework/http/types/http-method.type.ts b/shared/src/framework/http/types/http-method.type.ts
index 884797ac9..3d15ae0aa 100644
--- a/shared/src/framework/http/types/http-method.type.ts
+++ b/shared/src/framework/http/types/http-method.type.ts
@@ -1,3 +1,3 @@
-type HttpMethod = 'GET' | 'POST';
+type HttpMethod = 'GET' | 'POST' | 'DELETE';
 
 export { type HttpMethod };

From 3a1ebc3c8651b442239e1c37d768bcee9527e020 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 00:41:18 +0300
Subject: [PATCH 21/48] OV-52: * OpenAISerrvice type

---
 backend/src/bundles/chat/libs/types/open-ai-service.type.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
index e988d31bf..f40d25104 100644
--- a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
@@ -2,6 +2,7 @@ import { type ValueOf } from 'shared';
 
 import { type OpenAIRole } from '../enums/enums.js';
 import { type Message } from './message.type.js';
+import { type SessionChatHistory } from './session-chat-history.js';
 
 type OpenAIService = {
     generateText(messages: Message[]): Promise<string>;
@@ -10,6 +11,7 @@ type OpenAIService = {
         userMessage: string,
         role: ValueOf<typeof OpenAIRole>,
     ): void;
+    clearChatHistory(session: SessionChatHistory): void;
 };
 
 export { type OpenAIService };

From 4e9549291d34fa7c77e7da1618af226501850137 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 00:42:22 +0300
Subject: [PATCH 22/48] OV-52: + clear chat logic

---
 backend/src/bundles/chat/chat.controller.ts | 23 +++++++++++++++++++++
 backend/src/bundles/chat/open-ai.service.ts |  5 +++++
 2 files changed, 28 insertions(+)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index a774afb8c..25b3c46c8 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -37,6 +37,17 @@ class ChatController extends BaseController {
                     }>,
                 ),
         });
+
+        this.addRoute({
+            path: ChatPath.ROOT,
+            method: HTTPMethod.DELETE,
+            handler: (options) =>
+                this.clearChat(
+                    options as ApiHandlerOptions<{
+                        session: SessionChatHistory;
+                    }>,
+                ),
+        });
     }
 
     private async generateChatAnswer(
@@ -68,6 +79,18 @@ class ChatController extends BaseController {
             status: HttpCode.OK,
         };
     }
+
+    private clearChat(
+        options: ApiHandlerOptions<{
+            session: SessionChatHistory;
+        }>,
+    ): ApiHandlerResponse {
+        this.openAIService.clearChatHistory(options.session);
+        return {
+            payload: true,
+            status: HttpCode.OK,
+        };
+    }
 }
 
 export { ChatController };
diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
index d04d927d4..265fe1d4b 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -8,6 +8,7 @@ import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
 import {
     type Message,
     type OpenAIService as OpenAIServiceModule,
+    type SessionChatHistory,
 } from './libs/types/types.js';
 
 class OpenAIService implements OpenAIServiceModule {
@@ -38,6 +39,10 @@ class OpenAIService implements OpenAIServiceModule {
         chatHistory.push(newUserMessage);
     }
 
+    public clearChatHistory(session: SessionChatHistory): void {
+        session.chatHistory = [];
+    }
+
     public async generateText(messages: Message[]): Promise<string> {
         const completion = await this.openAi.chat.completions.create({
             messages,

From 6d3f7e000e5646255938f740bcf02ed5348ccb62 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:17:13 +0300
Subject: [PATCH 23/48] OV-52: - sessionChatHistory type

---
 .../src/bundles/chat/libs/types/session-chat-history.ts    | 7 -------
 1 file changed, 7 deletions(-)
 delete mode 100644 backend/src/bundles/chat/libs/types/session-chat-history.ts

diff --git a/backend/src/bundles/chat/libs/types/session-chat-history.ts b/backend/src/bundles/chat/libs/types/session-chat-history.ts
deleted file mode 100644
index 02ce4a1a0..000000000
--- a/backend/src/bundles/chat/libs/types/session-chat-history.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-import { type Message } from './message.type.js';
-
-type SessionChatHistory = {
-    chatHistory: Message[];
-};
-
-export { type SessionChatHistory };

From 331a987588b4ae0d7f71b8f50ea192c3983f226f Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:17:45 +0300
Subject: [PATCH 24/48] OV-52: + tiktoken package

---
 backend/package.json | 3 ++-
 package-lock.json    | 8 +++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/backend/package.json b/backend/package.json
index e1e718217..823fa5f0d 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -45,6 +45,7 @@
         "pino": "9.3.2",
         "pino-pretty": "10.3.1",
         "shared": "*",
-        "swagger-jsdoc": "6.2.8"
+        "swagger-jsdoc": "6.2.8",
+        "tiktoken": "1.0.16"
     }
 }
diff --git a/package-lock.json b/package-lock.json
index b1734afd5..3ff325381 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -55,7 +55,8 @@
                 "pino": "9.3.2",
                 "pino-pretty": "10.3.1",
                 "shared": "*",
-                "swagger-jsdoc": "6.2.8"
+                "swagger-jsdoc": "6.2.8",
+                "tiktoken": "1.0.16"
             },
             "devDependencies": {
                 "@types/bcrypt": "5.0.2",
@@ -12486,6 +12487,11 @@
             "integrity": "sha512-w89qg7PI8wAdvX60bMDP+bFoD5Dvhm9oLheFp5O4a2QF0cSBGsBX4qZmadPMvVqlLJBBci+WqGGOAPvcDeNSVg==",
             "dev": true
         },
+        "node_modules/tiktoken": {
+            "version": "1.0.16",
+            "resolved": "https://registry.npmjs.org/tiktoken/-/tiktoken-1.0.16.tgz",
+            "integrity": "sha512-hRcORIGF2YlAgWx3nzrGJOrKSJwLoc81HpXmMQk89632XAgURc7IeV2FgQ2iXo9z/J96fCvpsHg2kWoHcbj9fg=="
+        },
         "node_modules/tildify": {
             "version": "2.0.0",
             "resolved": "https://registry.npmjs.org/tildify/-/tildify-2.0.0.tgz",

From d5438bf675cde8f69c07d659867a5f95da82e57c Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:18:27 +0300
Subject: [PATCH 25/48] OV-52: * HttpMethod type

---
 shared/src/framework/http/types/http-method.type.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/shared/src/framework/http/types/http-method.type.ts b/shared/src/framework/http/types/http-method.type.ts
index 3d15ae0aa..6ef53eadb 100644
--- a/shared/src/framework/http/types/http-method.type.ts
+++ b/shared/src/framework/http/types/http-method.type.ts
@@ -1,3 +1,3 @@
-type HttpMethod = 'GET' | 'POST' | 'DELETE';
+type HttpMethod = 'GET' | 'POST' | 'DELETE' | 'PUT';
 
 export { type HttpMethod };

From 37c3dd9a5ab9f720de2127990f3f10bae3af04df Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:19:05 +0300
Subject: [PATCH 26/48] OV-52: - sessionChatHistory type

---
 backend/src/bundles/chat/libs/types/types.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/backend/src/bundles/chat/libs/types/types.ts b/backend/src/bundles/chat/libs/types/types.ts
index 92b6f0cbc..0da5cca46 100644
--- a/backend/src/bundles/chat/libs/types/types.ts
+++ b/backend/src/bundles/chat/libs/types/types.ts
@@ -1,4 +1,3 @@
 export { type Message } from './message.type.js';
 export { type OpenAIService } from './open-ai-service.type.js';
-export { type SessionChatHistory } from './session-chat-history.js';
 export { type GenerateTextRequestDto } from 'shared';

From d76157a1ae168cde2e7e527eeef69ccdfab64ea9 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:21:27 +0300
Subject: [PATCH 27/48] OV-52: * MAX_TOKEN

---
 backend/src/bundles/chat/libs/constants/max-token.constant.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/src/bundles/chat/libs/constants/max-token.constant.ts b/backend/src/bundles/chat/libs/constants/max-token.constant.ts
index 886179719..dcc301f98 100644
--- a/backend/src/bundles/chat/libs/constants/max-token.constant.ts
+++ b/backend/src/bundles/chat/libs/constants/max-token.constant.ts
@@ -1,3 +1,3 @@
-const MAX_TOKEN = 2048 as const;
+const MAX_TOKEN = 16_000 as const;
 
 export { MAX_TOKEN };

From 33b4c70f70ab0525fb26bceea4c114cb8c10a7b0 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:22:41 +0300
Subject: [PATCH 28/48] OV-52: + delete old messages logic

---
 .../chat/libs/types/open-ai-service.type.ts   |  4 +--
 backend/src/bundles/chat/open-ai.service.ts   | 35 ++++++++++++++++---
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
index f40d25104..a71a9b36f 100644
--- a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
@@ -2,7 +2,6 @@ import { type ValueOf } from 'shared';
 
 import { type OpenAIRole } from '../enums/enums.js';
 import { type Message } from './message.type.js';
-import { type SessionChatHistory } from './session-chat-history.js';
 
 type OpenAIService = {
     generateText(messages: Message[]): Promise<string>;
@@ -11,7 +10,8 @@ type OpenAIService = {
         userMessage: string,
         role: ValueOf<typeof OpenAIRole>,
     ): void;
-    clearChatHistory(session: SessionChatHistory): void;
+    clearChatHistory(messages: Message[]): void;
+    deleteOldMessages(messages: Message[], maxTokens: number): void;
 };
 
 export { type OpenAIService };
diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
index 265fe1d4b..96f79a6b9 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -1,5 +1,6 @@
 import OpenAI, { type OpenAI as OpenAIType } from 'openai';
 import { type ValueOf } from 'shared';
+import { type Tiktoken, encoding_for_model } from 'tiktoken';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
 
@@ -8,16 +9,17 @@ import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
 import {
     type Message,
     type OpenAIService as OpenAIServiceModule,
-    type SessionChatHistory,
 } from './libs/types/types.js';
 
 class OpenAIService implements OpenAIServiceModule {
     private config: BaseConfig;
     private openAi: OpenAIType;
+    private modelEncoding: Tiktoken;
 
     public constructor(config: BaseConfig) {
         this.config = config;
         this.openAi = this.initOpenAi();
+        this.modelEncoding = encoding_for_model('gpt-4o-mini');
     }
 
     private initOpenAi = (): OpenAIType => {
@@ -39,8 +41,8 @@ class OpenAIService implements OpenAIServiceModule {
         chatHistory.push(newUserMessage);
     }
 
-    public clearChatHistory(session: SessionChatHistory): void {
-        session.chatHistory = [];
+    public clearChatHistory(messages: Message[]): void {
+        messages.splice(0, messages.length);
     }
 
     public async generateText(messages: Message[]): Promise<string> {
@@ -49,9 +51,34 @@ class OpenAIService implements OpenAIServiceModule {
             model: CHAT_MODEL,
             max_tokens: MAX_TOKEN,
         });
-
         return completion.choices[0]?.message.content || '';
     }
+
+    private countTokens(messages: Message[]): number {
+        return messages.reduce(
+            (sum, message) =>
+                sum + this.modelEncoding.encode(message.content).length,
+            0,
+        );
+    }
+
+    public deleteOldMessages(messages: Message[], maxTokens: number): void {
+        let totalTokens = this.countTokens(messages);
+
+        while (totalTokens > maxTokens) {
+            const removedMessage = messages[1];
+
+            if (!removedMessage) {
+                break;
+            }
+
+            messages.splice(1, 1);
+
+            totalTokens -= this.modelEncoding.encode(
+                removedMessage.content,
+            ).length;
+        }
+    }
 }
 
 export { OpenAIService };

From 6b646bbcdee4f23a96d2d89e08f930cbd288c1ea Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:24:19 +0300
Subject: [PATCH 29/48] OV-52: + delete session handler

---
 backend/src/bundles/chat/chat.controller.ts | 55 +++++++++++++++++----
 1 file changed, 45 insertions(+), 10 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 25b3c46c8..9d106a52b 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -1,3 +1,5 @@
+import { type FastifySessionObject } from '@fastify/session';
+
 import {
     type ApiHandlerOptions,
     type ApiHandlerResponse,
@@ -7,11 +9,9 @@ import { ApiPath } from '~/common/enums/enums.js';
 import { HttpCode, HTTPMethod } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
 
+import { MAX_TOKEN } from './libs/constants/max-token.constant.js';
 import { ChatPath, OpenAIRole } from './libs/enums/enums.js';
-import {
-    type GenerateTextRequestDto,
-    type SessionChatHistory,
-} from './libs/types/types.js';
+import { type GenerateTextRequestDto } from './libs/types/types.js';
 import { textGenerationValidationSchema } from './libs/validation-schemas/validation-schemas.js';
 import { type OpenAIService } from './open-ai.service.js';
 
@@ -25,7 +25,7 @@ class ChatController extends BaseController {
 
         this.addRoute({
             path: ChatPath.ROOT,
-            method: HTTPMethod.POST,
+            method: HTTPMethod.PUT,
             validation: {
                 body: textGenerationValidationSchema,
             },
@@ -33,7 +33,7 @@ class ChatController extends BaseController {
                 this.generateChatAnswer(
                     options as ApiHandlerOptions<{
                         body: GenerateTextRequestDto;
-                        session: SessionChatHistory;
+                        session: FastifySessionObject;
                     }>,
                 ),
         });
@@ -44,16 +44,49 @@ class ChatController extends BaseController {
             handler: (options) =>
                 this.clearChat(
                     options as ApiHandlerOptions<{
-                        session: SessionChatHistory;
+                        session: FastifySessionObject;
+                    }>,
+                ),
+        });
+
+        this.addRoute({
+            path: ChatPath.ROOT,
+            method: HTTPMethod.POST,
+            handler: (options) =>
+                this.deleteSession(
+                    options as ApiHandlerOptions<{
+                        session: FastifySessionObject;
                     }>,
                 ),
         });
     }
 
+    private deleteSession(
+        options: ApiHandlerOptions<{
+            session: FastifySessionObject;
+        }>,
+    ): ApiHandlerResponse {
+        const { session } = options;
+
+        session.destroy((error) => {
+            if (error) {
+                return {
+                    payload: false,
+                    status: HttpCode.INTERNAL_SERVER_ERROR,
+                };
+            }
+        });
+
+        return {
+            payload: true,
+            status: HttpCode.OK,
+        };
+    }
+
     private async generateChatAnswer(
         options: ApiHandlerOptions<{
             body: GenerateTextRequestDto;
-            session: SessionChatHistory;
+            session: FastifySessionObject;
         }>,
     ): Promise<ApiHandlerResponse> {
         const { body, session } = options;
@@ -64,6 +97,8 @@ class ChatController extends BaseController {
             OpenAIRole.USER,
         );
 
+        this.openAIService.deleteOldMessages(session.chatHistory, MAX_TOKEN);
+
         const generatedText = await this.openAIService.generateText(
             session.chatHistory,
         );
@@ -82,10 +117,10 @@ class ChatController extends BaseController {
 
     private clearChat(
         options: ApiHandlerOptions<{
-            session: SessionChatHistory;
+            session: FastifySessionObject;
         }>,
     ): ApiHandlerResponse {
-        this.openAIService.clearChatHistory(options.session);
+        this.openAIService.clearChatHistory(options.session.chatHistory);
         return {
             payload: true,
             status: HttpCode.OK,

From 1c3f5efd13eb65362ede76f502b4a1ef490f76b2 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 14:54:39 +0300
Subject: [PATCH 30/48] OV-52: * openAi service

---
 backend/src/bundles/chat/open-ai.service.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
index 96f79a6b9..6005a2f71 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -72,7 +72,7 @@ class OpenAIService implements OpenAIServiceModule {
                 break;
             }
 
-            messages.splice(1, 1);
+            messages.splice(0, 1);
 
             totalTokens -= this.modelEncoding.encode(
                 removedMessage.content,

From ff6f18c2ca1488f96b74f77592454d1241b55a0e Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Sat, 24 Aug 2024 15:19:54 +0300
Subject: [PATCH 31/48] OV-52: * openAi service

---
 backend/src/bundles/chat/open-ai.service.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
index 6005a2f71..afc307b86 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -66,7 +66,7 @@ class OpenAIService implements OpenAIServiceModule {
         let totalTokens = this.countTokens(messages);
 
         while (totalTokens > maxTokens) {
-            const removedMessage = messages[1];
+            const removedMessage = messages[0];
 
             if (!removedMessage) {
                 break;

From d400b39dbdf89a1e384c0da9c5ff403cab53194e Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Mon, 26 Aug 2024 21:31:23 +0300
Subject: [PATCH 32/48] OV-52: + chat service

---
 backend/src/bundles/chat/char.service.ts      | 61 +++++++++++++++++++
 .../chat/libs/types/chat-service.type.ts      | 16 +++++
 backend/src/bundles/chat/libs/types/types.ts  |  1 +
 3 files changed, 78 insertions(+)
 create mode 100644 backend/src/bundles/chat/char.service.ts
 create mode 100644 backend/src/bundles/chat/libs/types/chat-service.type.ts

diff --git a/backend/src/bundles/chat/char.service.ts b/backend/src/bundles/chat/char.service.ts
new file mode 100644
index 000000000..2753fbe37
--- /dev/null
+++ b/backend/src/bundles/chat/char.service.ts
@@ -0,0 +1,61 @@
+import { type ValueOf } from 'shared';
+import { type Tiktoken, encoding_for_model } from 'tiktoken';
+
+import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
+import {
+    type ChatService as ChatServiceT,
+    type Message,
+} from './libs/types/types.js';
+
+class ChatService implements ChatServiceT {
+    private modelEncoding: Tiktoken;
+
+    public constructor() {
+        this.modelEncoding = encoding_for_model('gpt-4o-mini');
+    }
+
+    public addMessageToHistory(
+        chatHistory: Message[],
+        userMessage: string,
+        role: ValueOf<typeof OpenAIRole>,
+    ): void {
+        const newUserMessage = {
+            content: userMessage,
+            role,
+        };
+
+        chatHistory.push(newUserMessage);
+    }
+
+    public clearChatHistory(messages: Message[]): void {
+        messages.splice(0, messages.length);
+    }
+
+    private countTokens(messages: Message[]): number {
+        return messages.reduce(
+            (sum, message) =>
+                sum + this.modelEncoding.encode(message.content).length,
+            0,
+        );
+    }
+
+    public deleteOldMessages(messages: Message[], maxTokens: number): void {
+        let totalTokens = this.countTokens(messages);
+
+        while (totalTokens > maxTokens) {
+            const removedMessage = messages[0];
+
+            if (!removedMessage) {
+                break;
+            }
+
+            messages.splice(0, 1);
+
+            totalTokens -= this.modelEncoding.encode(
+                removedMessage.content,
+            ).length;
+        }
+    }
+}
+
+export { ChatService };
diff --git a/backend/src/bundles/chat/libs/types/chat-service.type.ts b/backend/src/bundles/chat/libs/types/chat-service.type.ts
new file mode 100644
index 000000000..bed7e3127
--- /dev/null
+++ b/backend/src/bundles/chat/libs/types/chat-service.type.ts
@@ -0,0 +1,16 @@
+import { type ValueOf } from 'shared';
+
+import { type OpenAIRole } from '../enums/enums.js';
+import { type Message } from './message.type.js';
+
+type ChatService = {
+    addMessageToHistory(
+        chatHistory: Message[],
+        userMessage: string,
+        role: ValueOf<typeof OpenAIRole>,
+    ): void;
+    clearChatHistory(messages: Message[]): void;
+    deleteOldMessages(messages: Message[], maxTokens: number): void;
+};
+
+export { type ChatService };
diff --git a/backend/src/bundles/chat/libs/types/types.ts b/backend/src/bundles/chat/libs/types/types.ts
index 0da5cca46..a77276783 100644
--- a/backend/src/bundles/chat/libs/types/types.ts
+++ b/backend/src/bundles/chat/libs/types/types.ts
@@ -1,3 +1,4 @@
+export { type ChatService } from './chat-service.type.js';
 export { type Message } from './message.type.js';
 export { type OpenAIService } from './open-ai-service.type.js';
 export { type GenerateTextRequestDto } from 'shared';

From 3ef2954dac7fc3d41e93709a9331f464f0b97aa5 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Mon, 26 Aug 2024 21:32:48 +0300
Subject: [PATCH 33/48] OV-52: * openAI service

---
 .../chat/libs/types/open-ai-service.type.ts   | 10 ----
 backend/src/bundles/chat/open-ai.service.ts   | 48 -------------------
 2 files changed, 58 deletions(-)

diff --git a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
index a71a9b36f..9963d9ccd 100644
--- a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
@@ -1,17 +1,7 @@
-import { type ValueOf } from 'shared';
-
-import { type OpenAIRole } from '../enums/enums.js';
 import { type Message } from './message.type.js';
 
 type OpenAIService = {
     generateText(messages: Message[]): Promise<string>;
-    addMessageToHistory(
-        chatHistory: Message[],
-        userMessage: string,
-        role: ValueOf<typeof OpenAIRole>,
-    ): void;
-    clearChatHistory(messages: Message[]): void;
-    deleteOldMessages(messages: Message[], maxTokens: number): void;
 };
 
 export { type OpenAIService };
diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/bundles/chat/open-ai.service.ts
index afc307b86..e863362cb 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/bundles/chat/open-ai.service.ts
@@ -1,11 +1,8 @@
 import OpenAI, { type OpenAI as OpenAIType } from 'openai';
-import { type ValueOf } from 'shared';
-import { type Tiktoken, encoding_for_model } from 'tiktoken';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
 
 import { CHAT_MODEL, MAX_TOKEN } from './libs/constants/constants.js';
-import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
 import {
     type Message,
     type OpenAIService as OpenAIServiceModule,
@@ -14,12 +11,10 @@ import {
 class OpenAIService implements OpenAIServiceModule {
     private config: BaseConfig;
     private openAi: OpenAIType;
-    private modelEncoding: Tiktoken;
 
     public constructor(config: BaseConfig) {
         this.config = config;
         this.openAi = this.initOpenAi();
-        this.modelEncoding = encoding_for_model('gpt-4o-mini');
     }
 
     private initOpenAi = (): OpenAIType => {
@@ -28,23 +23,6 @@ class OpenAIService implements OpenAIServiceModule {
         });
     };
 
-    public addMessageToHistory(
-        chatHistory: Message[],
-        userMessage: string,
-        role: ValueOf<typeof OpenAIRole>,
-    ): void {
-        const newUserMessage = {
-            content: userMessage,
-            role,
-        };
-
-        chatHistory.push(newUserMessage);
-    }
-
-    public clearChatHistory(messages: Message[]): void {
-        messages.splice(0, messages.length);
-    }
-
     public async generateText(messages: Message[]): Promise<string> {
         const completion = await this.openAi.chat.completions.create({
             messages,
@@ -53,32 +31,6 @@ class OpenAIService implements OpenAIServiceModule {
         });
         return completion.choices[0]?.message.content || '';
     }
-
-    private countTokens(messages: Message[]): number {
-        return messages.reduce(
-            (sum, message) =>
-                sum + this.modelEncoding.encode(message.content).length,
-            0,
-        );
-    }
-
-    public deleteOldMessages(messages: Message[], maxTokens: number): void {
-        let totalTokens = this.countTokens(messages);
-
-        while (totalTokens > maxTokens) {
-            const removedMessage = messages[0];
-
-            if (!removedMessage) {
-                break;
-            }
-
-            messages.splice(0, 1);
-
-            totalTokens -= this.modelEncoding.encode(
-                removedMessage.content,
-            ).length;
-        }
-    }
 }
 
 export { OpenAIService };

From e0f6a4722138f301eacaa8427d37cdd8c24e4fbd Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Mon, 26 Aug 2024 21:34:11 +0300
Subject: [PATCH 34/48] OV-52: * chat controller

---
 backend/src/bundles/chat/chat.controller.ts | 52 ++++++---------------
 backend/src/bundles/chat/chat.ts            |  4 +-
 2 files changed, 16 insertions(+), 40 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 9d106a52b..695ff541a 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -9,6 +9,7 @@ import { ApiPath } from '~/common/enums/enums.js';
 import { HttpCode, HTTPMethod } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
 
+import { type ChatService } from './char.service.js';
 import { MAX_TOKEN } from './libs/constants/max-token.constant.js';
 import { ChatPath, OpenAIRole } from './libs/enums/enums.js';
 import { type GenerateTextRequestDto } from './libs/types/types.js';
@@ -17,15 +18,21 @@ import { type OpenAIService } from './open-ai.service.js';
 
 class ChatController extends BaseController {
     private openAIService: OpenAIService;
+    private chatService: ChatService;
 
-    public constructor(logger: Logger, openAIService: OpenAIService) {
+    public constructor(
+        logger: Logger,
+        openAIService: OpenAIService,
+        chatService: ChatService,
+    ) {
         super(logger, ApiPath.CHAT);
 
         this.openAIService = openAIService;
+        this.chatService = chatService;
 
         this.addRoute({
             path: ChatPath.ROOT,
-            method: HTTPMethod.PUT,
+            method: HTTPMethod.POST,
             validation: {
                 body: textGenerationValidationSchema,
             },
@@ -48,39 +55,6 @@ class ChatController extends BaseController {
                     }>,
                 ),
         });
-
-        this.addRoute({
-            path: ChatPath.ROOT,
-            method: HTTPMethod.POST,
-            handler: (options) =>
-                this.deleteSession(
-                    options as ApiHandlerOptions<{
-                        session: FastifySessionObject;
-                    }>,
-                ),
-        });
-    }
-
-    private deleteSession(
-        options: ApiHandlerOptions<{
-            session: FastifySessionObject;
-        }>,
-    ): ApiHandlerResponse {
-        const { session } = options;
-
-        session.destroy((error) => {
-            if (error) {
-                return {
-                    payload: false,
-                    status: HttpCode.INTERNAL_SERVER_ERROR,
-                };
-            }
-        });
-
-        return {
-            payload: true,
-            status: HttpCode.OK,
-        };
     }
 
     private async generateChatAnswer(
@@ -91,19 +65,19 @@ class ChatController extends BaseController {
     ): Promise<ApiHandlerResponse> {
         const { body, session } = options;
 
-        this.openAIService.addMessageToHistory(
+        this.chatService.addMessageToHistory(
             session.chatHistory,
             body.message,
             OpenAIRole.USER,
         );
 
-        this.openAIService.deleteOldMessages(session.chatHistory, MAX_TOKEN);
+        this.chatService.deleteOldMessages(session.chatHistory, MAX_TOKEN);
 
         const generatedText = await this.openAIService.generateText(
             session.chatHistory,
         );
 
-        this.openAIService.addMessageToHistory(
+        this.chatService.addMessageToHistory(
             session.chatHistory,
             generatedText,
             OpenAIRole.ASSISTANT,
@@ -120,7 +94,7 @@ class ChatController extends BaseController {
             session: FastifySessionObject;
         }>,
     ): ApiHandlerResponse {
-        this.openAIService.clearChatHistory(options.session.chatHistory);
+        this.chatService.clearChatHistory(options.session.chatHistory);
         return {
             payload: true,
             status: HttpCode.OK,
diff --git a/backend/src/bundles/chat/chat.ts b/backend/src/bundles/chat/chat.ts
index a77b520d5..3e9463ef8 100644
--- a/backend/src/bundles/chat/chat.ts
+++ b/backend/src/bundles/chat/chat.ts
@@ -1,10 +1,12 @@
 import { config } from '~/common/config/config.js';
 import { logger } from '~/common/logger/logger.js';
 
+import { ChatService } from './char.service.js';
 import { ChatController } from './chat.controller.js';
 import { OpenAIService } from './open-ai.service.js';
 
 const openAIService = new OpenAIService(config);
-const chatController = new ChatController(logger, openAIService);
+const chatService = new ChatService();
+const chatController = new ChatController(logger, openAIService, chatService);
 
 export { chatController };

From 1029592ecfcd7362552fd756da799ce6703f3451 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Mon, 26 Aug 2024 22:01:07 +0300
Subject: [PATCH 35/48] OV-52: * chat service

---
 backend/src/bundles/chat/char.service.ts      | 19 ++++++++++---------
 .../chat/libs/types/chat-service.type.ts      |  1 -
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/backend/src/bundles/chat/char.service.ts b/backend/src/bundles/chat/char.service.ts
index 2753fbe37..85646a66f 100644
--- a/backend/src/bundles/chat/char.service.ts
+++ b/backend/src/bundles/chat/char.service.ts
@@ -27,10 +27,6 @@ class ChatService implements ChatServiceT {
         chatHistory.push(newUserMessage);
     }
 
-    public clearChatHistory(messages: Message[]): void {
-        messages.splice(0, messages.length);
-    }
-
     private countTokens(messages: Message[]): number {
         return messages.reduce(
             (sum, message) =>
@@ -39,22 +35,27 @@ class ChatService implements ChatServiceT {
         );
     }
 
-    public deleteOldMessages(messages: Message[], maxTokens: number): void {
+    public deleteOldMessages(
+        messages: Message[],
+        maxTokens: number,
+    ): Message[] {
         let totalTokens = this.countTokens(messages);
+        let updatedMessages = [...messages];
 
-        while (totalTokens > maxTokens) {
-            const removedMessage = messages[0];
+        while (totalTokens > maxTokens && updatedMessages.length > 0) {
+            const [removedMessage, ...rest] = updatedMessages;
+            updatedMessages = rest;
 
             if (!removedMessage) {
                 break;
             }
 
-            messages.splice(0, 1);
-
             totalTokens -= this.modelEncoding.encode(
                 removedMessage.content,
             ).length;
         }
+
+        return updatedMessages;
     }
 }
 
diff --git a/backend/src/bundles/chat/libs/types/chat-service.type.ts b/backend/src/bundles/chat/libs/types/chat-service.type.ts
index bed7e3127..ac38ed591 100644
--- a/backend/src/bundles/chat/libs/types/chat-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/chat-service.type.ts
@@ -9,7 +9,6 @@ type ChatService = {
         userMessage: string,
         role: ValueOf<typeof OpenAIRole>,
     ): void;
-    clearChatHistory(messages: Message[]): void;
     deleteOldMessages(messages: Message[], maxTokens: number): void;
 };
 

From dec288083aa58e1e18fbc81b8c5b88c890d8f41d Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Mon, 26 Aug 2024 22:03:35 +0300
Subject: [PATCH 36/48] OV-52: * chat controller

---
 backend/src/bundles/chat/chat.controller.ts | 42 +++++++++++++++++++--
 shared/src/bundles/chat/enums/chat.enum.ts  |  2 +
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 695ff541a..48fca22dd 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -46,7 +46,7 @@ class ChatController extends BaseController {
         });
 
         this.addRoute({
-            path: ChatPath.ROOT,
+            path: ChatPath.CLEAR,
             method: HTTPMethod.DELETE,
             handler: (options) =>
                 this.clearChat(
@@ -55,6 +55,17 @@ class ChatController extends BaseController {
                     }>,
                 ),
         });
+
+        this.addRoute({
+            path: ChatPath.END,
+            method: HTTPMethod.DELETE,
+            handler: (options) =>
+                this.deleteSession(
+                    options as ApiHandlerOptions<{
+                        session: FastifySessionObject;
+                    }>,
+                ),
+        });
     }
 
     private async generateChatAnswer(
@@ -71,7 +82,10 @@ class ChatController extends BaseController {
             OpenAIRole.USER,
         );
 
-        this.chatService.deleteOldMessages(session.chatHistory, MAX_TOKEN);
+        session.chatHistory = this.chatService.deleteOldMessages(
+            session.chatHistory,
+            MAX_TOKEN,
+        );
 
         const generatedText = await this.openAIService.generateText(
             session.chatHistory,
@@ -94,7 +108,29 @@ class ChatController extends BaseController {
             session: FastifySessionObject;
         }>,
     ): ApiHandlerResponse {
-        this.chatService.clearChatHistory(options.session.chatHistory);
+        options.session.chatHistory = [];
+        return {
+            payload: true,
+            status: HttpCode.OK,
+        };
+    }
+
+    private deleteSession(
+        options: ApiHandlerOptions<{
+            session: FastifySessionObject;
+        }>,
+    ): ApiHandlerResponse {
+        const { session } = options;
+
+        session.destroy((error) => {
+            if (error) {
+                return {
+                    payload: false,
+                    status: HttpCode.INTERNAL_SERVER_ERROR,
+                };
+            }
+        });
+
         return {
             payload: true,
             status: HttpCode.OK,
diff --git a/shared/src/bundles/chat/enums/chat.enum.ts b/shared/src/bundles/chat/enums/chat.enum.ts
index 5580c6237..e6a959781 100644
--- a/shared/src/bundles/chat/enums/chat.enum.ts
+++ b/shared/src/bundles/chat/enums/chat.enum.ts
@@ -1,5 +1,7 @@
 const ChatPath = {
     ROOT: '/',
+    END: '/end',
+    CLEAR: '/clear',
 } as const;
 
 export { ChatPath };

From 053a0dd9212956c67385d125f9e961afe462e2c0 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 00:32:31 +0300
Subject: [PATCH 37/48] OV-52: * move OpenAi service

---
 backend/src/bundles/chat/char.service.ts                 | 6 ++++--
 backend/src/bundles/chat/chat.controller.ts              | 9 ++++++---
 backend/src/bundles/chat/chat.ts                         | 4 +---
 backend/src/bundles/chat/libs/types/chat-service.type.ts | 3 ++-
 backend/src/bundles/chat/libs/types/message.type.ts      | 2 +-
 backend/src/bundles/chat/libs/types/types.ts             | 1 -
 .../open-ai}/libs/constants/chat-model.constant.ts       | 0
 .../services/open-ai}/libs/constants/constants.ts        | 0
 .../open-ai}/libs/constants/max-token.constant.ts        | 0
 .../chat => common/services/open-ai}/libs/enums/enums.ts | 0
 .../services/open-ai}/libs/enums/open-ai-role.enum.ts    | 0
 .../services/open-ai}/libs/types/open-ai-service.type.ts | 2 +-
 backend/src/common/services/open-ai/libs/types/types.ts  | 1 +
 .../chat => common/services/open-ai}/open-ai.service.ts  | 8 +++-----
 backend/src/common/services/services.ts                  | 5 ++++-
 15 files changed, 23 insertions(+), 18 deletions(-)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/constants/chat-model.constant.ts (100%)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/constants/constants.ts (100%)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/constants/max-token.constant.ts (100%)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/enums/enums.ts (100%)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/enums/open-ai-role.enum.ts (100%)
 rename backend/src/{bundles/chat => common/services/open-ai}/libs/types/open-ai-service.type.ts (63%)
 create mode 100644 backend/src/common/services/open-ai/libs/types/types.ts
 rename backend/src/{bundles/chat => common/services/open-ai}/open-ai.service.ts (81%)

diff --git a/backend/src/bundles/chat/char.service.ts b/backend/src/bundles/chat/char.service.ts
index 85646a66f..2c2cb0909 100644
--- a/backend/src/bundles/chat/char.service.ts
+++ b/backend/src/bundles/chat/char.service.ts
@@ -1,7 +1,9 @@
 import { type ValueOf } from 'shared';
 import { type Tiktoken, encoding_for_model } from 'tiktoken';
 
-import { type OpenAIRole } from './libs/enums/open-ai-role.enum.js';
+import { CHAT_MODEL } from '~/common/services/open-ai/libs/constants/constants.js';
+import { type OpenAIRole } from '~/common/services/open-ai/libs/enums/enums.js';
+
 import {
     type ChatService as ChatServiceT,
     type Message,
@@ -11,7 +13,7 @@ class ChatService implements ChatServiceT {
     private modelEncoding: Tiktoken;
 
     public constructor() {
-        this.modelEncoding = encoding_for_model('gpt-4o-mini');
+        this.modelEncoding = encoding_for_model(CHAT_MODEL);
     }
 
     public addMessageToHistory(
diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 48fca22dd..26faf4511 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -9,12 +9,15 @@ import { ApiPath } from '~/common/enums/enums.js';
 import { HttpCode, HTTPMethod } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
 
+import { MAX_TOKEN } from '../../common/services/open-ai/libs/constants/max-token.constant.js';
+import {
+    ChatPath,
+    OpenAIRole,
+} from '../../common/services/open-ai/libs/enums/enums.js';
+import { type OpenAIService } from '../../common/services/open-ai/open-ai.service.js';
 import { type ChatService } from './char.service.js';
-import { MAX_TOKEN } from './libs/constants/max-token.constant.js';
-import { ChatPath, OpenAIRole } from './libs/enums/enums.js';
 import { type GenerateTextRequestDto } from './libs/types/types.js';
 import { textGenerationValidationSchema } from './libs/validation-schemas/validation-schemas.js';
-import { type OpenAIService } from './open-ai.service.js';
 
 class ChatController extends BaseController {
     private openAIService: OpenAIService;
diff --git a/backend/src/bundles/chat/chat.ts b/backend/src/bundles/chat/chat.ts
index 3e9463ef8..b87f6795f 100644
--- a/backend/src/bundles/chat/chat.ts
+++ b/backend/src/bundles/chat/chat.ts
@@ -1,11 +1,9 @@
-import { config } from '~/common/config/config.js';
 import { logger } from '~/common/logger/logger.js';
+import { openAIService } from '~/common/services/services.js';
 
 import { ChatService } from './char.service.js';
 import { ChatController } from './chat.controller.js';
-import { OpenAIService } from './open-ai.service.js';
 
-const openAIService = new OpenAIService(config);
 const chatService = new ChatService();
 const chatController = new ChatController(logger, openAIService, chatService);
 
diff --git a/backend/src/bundles/chat/libs/types/chat-service.type.ts b/backend/src/bundles/chat/libs/types/chat-service.type.ts
index ac38ed591..508b3ad62 100644
--- a/backend/src/bundles/chat/libs/types/chat-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/chat-service.type.ts
@@ -1,6 +1,7 @@
 import { type ValueOf } from 'shared';
 
-import { type OpenAIRole } from '../enums/enums.js';
+import { type OpenAIRole } from '~/common/services/open-ai/libs/enums/enums.js';
+
 import { type Message } from './message.type.js';
 
 type ChatService = {
diff --git a/backend/src/bundles/chat/libs/types/message.type.ts b/backend/src/bundles/chat/libs/types/message.type.ts
index 1bd4ee658..593eff87b 100644
--- a/backend/src/bundles/chat/libs/types/message.type.ts
+++ b/backend/src/bundles/chat/libs/types/message.type.ts
@@ -1,6 +1,6 @@
 import { type ValueOf } from 'shared';
 
-import { type OpenAIRole } from '../enums/enums.js';
+import { type OpenAIRole } from '~/common/services/open-ai/libs/enums/enums.js';
 
 type Message = {
     role: ValueOf<typeof OpenAIRole>;
diff --git a/backend/src/bundles/chat/libs/types/types.ts b/backend/src/bundles/chat/libs/types/types.ts
index a77276783..f1c0dba0e 100644
--- a/backend/src/bundles/chat/libs/types/types.ts
+++ b/backend/src/bundles/chat/libs/types/types.ts
@@ -1,4 +1,3 @@
 export { type ChatService } from './chat-service.type.js';
 export { type Message } from './message.type.js';
-export { type OpenAIService } from './open-ai-service.type.js';
 export { type GenerateTextRequestDto } from 'shared';
diff --git a/backend/src/bundles/chat/libs/constants/chat-model.constant.ts b/backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts
similarity index 100%
rename from backend/src/bundles/chat/libs/constants/chat-model.constant.ts
rename to backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts
diff --git a/backend/src/bundles/chat/libs/constants/constants.ts b/backend/src/common/services/open-ai/libs/constants/constants.ts
similarity index 100%
rename from backend/src/bundles/chat/libs/constants/constants.ts
rename to backend/src/common/services/open-ai/libs/constants/constants.ts
diff --git a/backend/src/bundles/chat/libs/constants/max-token.constant.ts b/backend/src/common/services/open-ai/libs/constants/max-token.constant.ts
similarity index 100%
rename from backend/src/bundles/chat/libs/constants/max-token.constant.ts
rename to backend/src/common/services/open-ai/libs/constants/max-token.constant.ts
diff --git a/backend/src/bundles/chat/libs/enums/enums.ts b/backend/src/common/services/open-ai/libs/enums/enums.ts
similarity index 100%
rename from backend/src/bundles/chat/libs/enums/enums.ts
rename to backend/src/common/services/open-ai/libs/enums/enums.ts
diff --git a/backend/src/bundles/chat/libs/enums/open-ai-role.enum.ts b/backend/src/common/services/open-ai/libs/enums/open-ai-role.enum.ts
similarity index 100%
rename from backend/src/bundles/chat/libs/enums/open-ai-role.enum.ts
rename to backend/src/common/services/open-ai/libs/enums/open-ai-role.enum.ts
diff --git a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts b/backend/src/common/services/open-ai/libs/types/open-ai-service.type.ts
similarity index 63%
rename from backend/src/bundles/chat/libs/types/open-ai-service.type.ts
rename to backend/src/common/services/open-ai/libs/types/open-ai-service.type.ts
index 9963d9ccd..5554a67f3 100644
--- a/backend/src/bundles/chat/libs/types/open-ai-service.type.ts
+++ b/backend/src/common/services/open-ai/libs/types/open-ai-service.type.ts
@@ -1,4 +1,4 @@
-import { type Message } from './message.type.js';
+import { type Message } from '~/bundles/chat/libs/types/types.js';
 
 type OpenAIService = {
     generateText(messages: Message[]): Promise<string>;
diff --git a/backend/src/common/services/open-ai/libs/types/types.ts b/backend/src/common/services/open-ai/libs/types/types.ts
new file mode 100644
index 000000000..332335022
--- /dev/null
+++ b/backend/src/common/services/open-ai/libs/types/types.ts
@@ -0,0 +1 @@
+export { type OpenAIService } from './open-ai-service.type.js';
diff --git a/backend/src/bundles/chat/open-ai.service.ts b/backend/src/common/services/open-ai/open-ai.service.ts
similarity index 81%
rename from backend/src/bundles/chat/open-ai.service.ts
rename to backend/src/common/services/open-ai/open-ai.service.ts
index e863362cb..81b3d8556 100644
--- a/backend/src/bundles/chat/open-ai.service.ts
+++ b/backend/src/common/services/open-ai/open-ai.service.ts
@@ -2,13 +2,11 @@ import OpenAI, { type OpenAI as OpenAIType } from 'openai';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
 
+import { type Message } from '../../../bundles/chat/libs/types/types.js';
 import { CHAT_MODEL, MAX_TOKEN } from './libs/constants/constants.js';
-import {
-    type Message,
-    type OpenAIService as OpenAIServiceModule,
-} from './libs/types/types.js';
+import { type OpenAIService as OpenAIServiceType } from './libs/types/types.js';
 
-class OpenAIService implements OpenAIServiceModule {
+class OpenAIService implements OpenAIServiceType {
     private config: BaseConfig;
     private openAi: OpenAIType;
 
diff --git a/backend/src/common/services/services.ts b/backend/src/common/services/services.ts
index 2be4c1278..037867ad1 100644
--- a/backend/src/common/services/services.ts
+++ b/backend/src/common/services/services.ts
@@ -1,5 +1,8 @@
+import { config } from '../config/config.js';
 import { CryptService } from './crypt/crypt.service.js';
+import { OpenAIService } from './open-ai/open-ai.service.js';
 
+const openAIService = new OpenAIService(config);
 const cryptService = new CryptService();
 
-export { cryptService };
+export { cryptService, openAIService };

From 6f50b86e63c927f11a468e6ff37c32877dcaa961 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 00:35:28 +0300
Subject: [PATCH 38/48] OV-52: * chat controller

---
 backend/src/bundles/chat/chat.controller.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 26faf4511..a892d8b98 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -8,8 +8,8 @@ import {
 import { ApiPath } from '~/common/enums/enums.js';
 import { HttpCode, HTTPMethod } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
+import { MAX_TOKEN } from '~/common/services/open-ai/libs/constants/constants.js';
 
-import { MAX_TOKEN } from '../../common/services/open-ai/libs/constants/max-token.constant.js';
 import {
     ChatPath,
     OpenAIRole,

From 1dbd3836645a85c02bf4e23a06e587fb8ebc4af2 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 13:29:05 +0300
Subject: [PATCH 39/48] OV-52: * rename

---
 backend/src/bundles/chat/chat.controller.ts                   | 2 +-
 backend/src/bundles/chat/{char.service.ts => chat.service.ts} | 0
 backend/src/bundles/chat/chat.ts                              | 2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)
 rename backend/src/bundles/chat/{char.service.ts => chat.service.ts} (100%)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index a892d8b98..2e3cef8cf 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -15,7 +15,7 @@ import {
     OpenAIRole,
 } from '../../common/services/open-ai/libs/enums/enums.js';
 import { type OpenAIService } from '../../common/services/open-ai/open-ai.service.js';
-import { type ChatService } from './char.service.js';
+import { type ChatService } from './chat.service.js';
 import { type GenerateTextRequestDto } from './libs/types/types.js';
 import { textGenerationValidationSchema } from './libs/validation-schemas/validation-schemas.js';
 
diff --git a/backend/src/bundles/chat/char.service.ts b/backend/src/bundles/chat/chat.service.ts
similarity index 100%
rename from backend/src/bundles/chat/char.service.ts
rename to backend/src/bundles/chat/chat.service.ts
diff --git a/backend/src/bundles/chat/chat.ts b/backend/src/bundles/chat/chat.ts
index b87f6795f..cf87e093b 100644
--- a/backend/src/bundles/chat/chat.ts
+++ b/backend/src/bundles/chat/chat.ts
@@ -1,8 +1,8 @@
 import { logger } from '~/common/logger/logger.js';
 import { openAIService } from '~/common/services/services.js';
 
-import { ChatService } from './char.service.js';
 import { ChatController } from './chat.controller.js';
+import { ChatService } from './chat.service.js';
 
 const chatService = new ChatService();
 const chatController = new ChatController(logger, openAIService, chatService);

From 222d36e9775262c7abadec2b6bb947e7b4480c00 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 14:23:18 +0300
Subject: [PATCH 40/48] OV-52: + swagger docs

---
 backend/src/bundles/chat/chat.controller.ts | 83 ++++++++++++++++++++-
 1 file changed, 79 insertions(+), 4 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index 2e3cef8cf..c6dd76ed6 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -71,6 +71,33 @@ class ChatController extends BaseController {
         });
     }
 
+    /**
+     * @swagger
+     * /chat/:
+     *    post:
+     *      description: Returns generated text by Open AI
+     *      requestBody:
+     *        description: User message
+     *        required: true
+     *        content:
+     *          application/json:
+     *            schema:
+     *              type: object
+     *              properties:
+     *                message:
+     *                  type: string
+     *      responses:
+     *        200:
+     *          description: Successful operation
+     *          content:
+     *            application/json:
+     *              schema:
+     *                type: object
+     *                properties:
+     *                  generatedText:
+     *                    type: string
+     */
+
     private async generateChatAnswer(
         options: ApiHandlerOptions<{
             body: GenerateTextRequestDto;
@@ -101,11 +128,31 @@ class ChatController extends BaseController {
         );
 
         return {
-            payload: generatedText,
+            payload: { generatedText },
             status: HttpCode.OK,
         };
     }
 
+    /**
+     * @swagger
+     * /chat/clear:
+     *    delete:
+     *      description: Clears chat history
+     *      requestBody:
+     *        description: User message
+     *        required: false
+     *      responses:
+     *        200:
+     *          description: Successful operation
+     *          content:
+     *            application/json:
+     *              schema:
+     *                type: object
+     *                properties:
+     *                  isCleared:
+     *                    type: boolean
+     */
+
     private clearChat(
         options: ApiHandlerOptions<{
             session: FastifySessionObject;
@@ -113,11 +160,39 @@ class ChatController extends BaseController {
     ): ApiHandlerResponse {
         options.session.chatHistory = [];
         return {
-            payload: true,
+            payload: { isCleared: true },
             status: HttpCode.OK,
         };
     }
 
+    /**
+     * @swagger
+     * /chat/end:
+     *    delete:
+     *      description: Clears chat history
+     *      requestBody:
+     *        description: User message
+     *        required: false
+     *      responses:
+     *        200:
+     *          description: Successful operation
+     *          content:
+     *            application/json:
+     *              schema:
+     *                type: object
+     *                properties:
+     *                  isDeleted:
+     *                    type: boolean
+     *        500:
+     *          description: Failed operation
+     *          content:
+     *            application/json:
+     *              schema:
+     *                  type: object
+     *                  properties:
+     *                    isDeleted:
+     *                      type: boolean
+     */
     private deleteSession(
         options: ApiHandlerOptions<{
             session: FastifySessionObject;
@@ -128,14 +203,14 @@ class ChatController extends BaseController {
         session.destroy((error) => {
             if (error) {
                 return {
-                    payload: false,
+                    payload: { isDeleted: false },
                     status: HttpCode.INTERNAL_SERVER_ERROR,
                 };
             }
         });
 
         return {
-            payload: true,
+            payload: { isDeleted: true },
             status: HttpCode.OK,
         };
     }

From 14cb9f3d1c33fe78b5c8e51f1de0f6ef438b1fd7 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 14:42:04 +0300
Subject: [PATCH 41/48] OV-52: * .env.example

---
 backend/.env.example | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/backend/.env.example b/backend/.env.example
index d9f0d5547..b98e1e61d 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -11,3 +11,13 @@ DB_CONNECTION_STRING=[db_client]://[db_username]:[db_user_password]@localhost:[d
 DB_DIALECT=pg
 DB_POOL_MIN=2
 DB_POOL_MAX=10
+
+#
+# OPEN AI
+#
+OPEN_AI_KEY=''
+
+#
+# SESSION
+#
+SESSION_KEY="SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY"

From 623fee7f8f05e4d6bfdc24fcc88bda104bc1bd80 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 16:36:20 +0300
Subject: [PATCH 42/48] OV-52: - as const

---
 .../services/open-ai/libs/constants/chat-model.constant.ts      | 2 +-
 .../services/open-ai/libs/constants/max-token.constant.ts       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts b/backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts
index 76241089d..385b505d5 100644
--- a/backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts
+++ b/backend/src/common/services/open-ai/libs/constants/chat-model.constant.ts
@@ -1,3 +1,3 @@
-const CHAT_MODEL = 'gpt-4o-mini' as const;
+const CHAT_MODEL = 'gpt-4o-mini';
 
 export { CHAT_MODEL };
diff --git a/backend/src/common/services/open-ai/libs/constants/max-token.constant.ts b/backend/src/common/services/open-ai/libs/constants/max-token.constant.ts
index dcc301f98..e403fe4b1 100644
--- a/backend/src/common/services/open-ai/libs/constants/max-token.constant.ts
+++ b/backend/src/common/services/open-ai/libs/constants/max-token.constant.ts
@@ -1,3 +1,3 @@
-const MAX_TOKEN = 16_000 as const;
+const MAX_TOKEN = 16_000;
 
 export { MAX_TOKEN };

From 567bd8b087cf075aeec2f6e2df6bfa2eb91ab73c Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 16:45:18 +0300
Subject: [PATCH 43/48] OV-52: * chat enum

---
 shared/src/bundles/chat/enums/chat.enum.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/shared/src/bundles/chat/enums/chat.enum.ts b/shared/src/bundles/chat/enums/chat.enum.ts
index e6a959781..5580c6237 100644
--- a/shared/src/bundles/chat/enums/chat.enum.ts
+++ b/shared/src/bundles/chat/enums/chat.enum.ts
@@ -1,7 +1,5 @@
 const ChatPath = {
     ROOT: '/',
-    END: '/end',
-    CLEAR: '/clear',
 } as const;
 
 export { ChatPath };

From 37664fb46732a17053cff6ce7db73e9f3a8b5a21 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 16:47:35 +0300
Subject: [PATCH 44/48] OV-52: * chat service

---
 backend/src/bundles/chat/chat.service.ts                 | 4 ++--
 backend/src/bundles/chat/libs/types/chat-service.type.ts | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/backend/src/bundles/chat/chat.service.ts b/backend/src/bundles/chat/chat.service.ts
index 2c2cb0909..d8451196b 100644
--- a/backend/src/bundles/chat/chat.service.ts
+++ b/backend/src/bundles/chat/chat.service.ts
@@ -20,13 +20,13 @@ class ChatService implements ChatServiceT {
         chatHistory: Message[],
         userMessage: string,
         role: ValueOf<typeof OpenAIRole>,
-    ): void {
+    ): Message[] {
         const newUserMessage = {
             content: userMessage,
             role,
         };
 
-        chatHistory.push(newUserMessage);
+        return [...chatHistory, newUserMessage];
     }
 
     private countTokens(messages: Message[]): number {
diff --git a/backend/src/bundles/chat/libs/types/chat-service.type.ts b/backend/src/bundles/chat/libs/types/chat-service.type.ts
index 508b3ad62..e1371d9b9 100644
--- a/backend/src/bundles/chat/libs/types/chat-service.type.ts
+++ b/backend/src/bundles/chat/libs/types/chat-service.type.ts
@@ -9,7 +9,7 @@ type ChatService = {
         chatHistory: Message[],
         userMessage: string,
         role: ValueOf<typeof OpenAIRole>,
-    ): void;
+    ): Message[];
     deleteOldMessages(messages: Message[], maxTokens: number): void;
 };
 

From 08d1e70716e818913a5d3c8f4419d9975204ed48 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 16:48:50 +0300
Subject: [PATCH 45/48] OV-52: * chat controller

---
 backend/src/bundles/chat/chat.controller.ts | 51 ++-------------------
 1 file changed, 4 insertions(+), 47 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index c6dd76ed6..ca161c2d9 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -49,18 +49,7 @@ class ChatController extends BaseController {
         });
 
         this.addRoute({
-            path: ChatPath.CLEAR,
-            method: HTTPMethod.DELETE,
-            handler: (options) =>
-                this.clearChat(
-                    options as ApiHandlerOptions<{
-                        session: FastifySessionObject;
-                    }>,
-                ),
-        });
-
-        this.addRoute({
-            path: ChatPath.END,
+            path: ChatPath.ROOT,
             method: HTTPMethod.DELETE,
             handler: (options) =>
                 this.deleteSession(
@@ -106,7 +95,7 @@ class ChatController extends BaseController {
     ): Promise<ApiHandlerResponse> {
         const { body, session } = options;
 
-        this.chatService.addMessageToHistory(
+        session.chatHistory = this.chatService.addMessageToHistory(
             session.chatHistory,
             body.message,
             OpenAIRole.USER,
@@ -121,7 +110,7 @@ class ChatController extends BaseController {
             session.chatHistory,
         );
 
-        this.chatService.addMessageToHistory(
+        session.chatHistory = this.chatService.addMessageToHistory(
             session.chatHistory,
             generatedText,
             OpenAIRole.ASSISTANT,
@@ -135,39 +124,7 @@ class ChatController extends BaseController {
 
     /**
      * @swagger
-     * /chat/clear:
-     *    delete:
-     *      description: Clears chat history
-     *      requestBody:
-     *        description: User message
-     *        required: false
-     *      responses:
-     *        200:
-     *          description: Successful operation
-     *          content:
-     *            application/json:
-     *              schema:
-     *                type: object
-     *                properties:
-     *                  isCleared:
-     *                    type: boolean
-     */
-
-    private clearChat(
-        options: ApiHandlerOptions<{
-            session: FastifySessionObject;
-        }>,
-    ): ApiHandlerResponse {
-        options.session.chatHistory = [];
-        return {
-            payload: { isCleared: true },
-            status: HttpCode.OK,
-        };
-    }
-
-    /**
-     * @swagger
-     * /chat/end:
+     * /chat/:
      *    delete:
      *      description: Clears chat history
      *      requestBody:

From 0f6688773627221a89f76f181d882de1810caad6 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Tue, 27 Aug 2024 16:51:42 +0300
Subject: [PATCH 46/48] OV-52: * openai service

---
 backend/src/common/services/open-ai/open-ai.service.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/backend/src/common/services/open-ai/open-ai.service.ts b/backend/src/common/services/open-ai/open-ai.service.ts
index 81b3d8556..980a10f8c 100644
--- a/backend/src/common/services/open-ai/open-ai.service.ts
+++ b/backend/src/common/services/open-ai/open-ai.service.ts
@@ -1,4 +1,4 @@
-import OpenAI, { type OpenAI as OpenAIType } from 'openai';
+import OpenAI from 'openai';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
 
@@ -8,14 +8,14 @@ import { type OpenAIService as OpenAIServiceType } from './libs/types/types.js';
 
 class OpenAIService implements OpenAIServiceType {
     private config: BaseConfig;
-    private openAi: OpenAIType;
+    private openAi: OpenAI;
 
     public constructor(config: BaseConfig) {
         this.config = config;
         this.openAi = this.initOpenAi();
     }
 
-    private initOpenAi = (): OpenAIType => {
+    private initOpenAi = (): OpenAI => {
         return new OpenAI({
             apiKey: this.config.ENV.APP.OPEN_AI_KEY,
         });

From a1eeb577ed0c6ad21f53f3a26b124de3a02f1180 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Wed, 28 Aug 2024 13:29:24 +0300
Subject: [PATCH 47/48] OV-52: * .env.example

---
 backend/.env.example | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/.env.example b/backend/.env.example
index 54907ec9d..41fd4ce5e 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -24,9 +24,9 @@ AWS_CLOUDFRONT_DOMAIN_ID=d2tm5q3cg1nlwf
 #
 # OPEN AI
 #
-OPEN_AI_KEY=''
+OPEN_AI_KEY=SOME_SECRET_KEY
 
 #
 # SESSION
 #
-SESSION_KEY="SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY_SECRET_KEY"
+SESSION_KEY=SOME_SECRET_KEY

From ded87cc6dd1cd456510aedab0b1121a47c70ba01 Mon Sep 17 00:00:00 2001
From: Sergiy <sergiy0378@gmail.com>
Date: Wed, 28 Aug 2024 20:01:49 +0300
Subject: [PATCH 48/48] OV-52: * exports

---
 backend/src/bundles/chat/chat.controller.ts              | 6 +++---
 backend/src/common/plugins/session/session.plugin.ts     | 3 +--
 backend/src/common/server-application/base-server-app.ts | 2 +-
 backend/src/common/services/services.ts                  | 3 ++-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/backend/src/bundles/chat/chat.controller.ts b/backend/src/bundles/chat/chat.controller.ts
index ca161c2d9..120e3c906 100644
--- a/backend/src/bundles/chat/chat.controller.ts
+++ b/backend/src/bundles/chat/chat.controller.ts
@@ -9,12 +9,12 @@ import { ApiPath } from '~/common/enums/enums.js';
 import { HttpCode, HTTPMethod } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
 import { MAX_TOKEN } from '~/common/services/open-ai/libs/constants/constants.js';
-
 import {
     ChatPath,
     OpenAIRole,
-} from '../../common/services/open-ai/libs/enums/enums.js';
-import { type OpenAIService } from '../../common/services/open-ai/open-ai.service.js';
+} from '~/common/services/open-ai/libs/enums/enums.js';
+import { type OpenAIService } from '~/common/services/open-ai/open-ai.service.js';
+
 import { type ChatService } from './chat.service.js';
 import { type GenerateTextRequestDto } from './libs/types/types.js';
 import { textGenerationValidationSchema } from './libs/validation-schemas/validation-schemas.js';
diff --git a/backend/src/common/plugins/session/session.plugin.ts b/backend/src/common/plugins/session/session.plugin.ts
index 047a7376e..c09beb8c3 100644
--- a/backend/src/common/plugins/session/session.plugin.ts
+++ b/backend/src/common/plugins/session/session.plugin.ts
@@ -3,8 +3,7 @@ import fastifySession from '@fastify/session';
 import fp from 'fastify-plugin';
 
 import { type BaseConfig } from '~/common/config/base-config.package.js';
-
-import { ControllerHook } from '../libs/enums/enums.js';
+import { ControllerHook } from '~/common/plugins/libs/enums/enums.js';
 
 type Options = {
     services: {
diff --git a/backend/src/common/server-application/base-server-app.ts b/backend/src/common/server-application/base-server-app.ts
index af0cf18be..8cba5608a 100644
--- a/backend/src/common/server-application/base-server-app.ts
+++ b/backend/src/common/server-application/base-server-app.ts
@@ -17,13 +17,13 @@ import { ServerErrorType } from '~/common/enums/enums.js';
 import { type ValidationError } from '~/common/exceptions/exceptions.js';
 import { HttpCode, HttpError } from '~/common/http/http.js';
 import { type Logger } from '~/common/logger/logger.js';
+import { session } from '~/common/plugins/session/session.plugin.js';
 import {
     type ServerCommonErrorResponse,
     type ServerValidationErrorResponse,
     type ValidationSchema,
 } from '~/common/types/types.js';
 
-import { session } from '../plugins/plugins.js';
 import {
     type ServerApp,
     type ServerAppApi,
diff --git a/backend/src/common/services/services.ts b/backend/src/common/services/services.ts
index 82acc8535..5a657b695 100644
--- a/backend/src/common/services/services.ts
+++ b/backend/src/common/services/services.ts
@@ -1,4 +1,5 @@
-import { config } from '../config/config.js';
+import { config } from '~/common/config/config.js';
+
 import { CryptService } from './crypt/crypt.service.js';
 import { FileService } from './file/file.service.js';
 import { OpenAIService } from './open-ai/open-ai.service.js';