Feat/language resolution (#375)

* Comments

* Added language choice

* wip

* it works

* Read lang files at startup

* validated lang files

* default language

* tests

* tests

* changelog

* lang files accept object structure

* beauty

---------

Co-authored-by: epessina <[email protected]>
Co-authored-by: Fabio Nappi <[email protected]>

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
 
+### Added
+
+- Languange resolution via Content Negotiation
+
 ## [3.0.6] - 2023-12-14
 
 ### Versioning

package.json

@@ -34,13 +34,16 @@
   },
   "dependencies": {
     "@apidevtools/json-schema-ref-parser": "^11.1.0",
+    "@fastify/accepts": "^4.3.0",
     "@mia-platform/custom-plugin-lib": "^6.0.0",
     "ajv": "^8.12.0",
     "commander": "^11.0.0",
     "fast-json-patch": "^3.1.1",
     "glob": "^10.3.10",
     "js-yaml": "^4.1.0",
     "jsonpath-plus": "^7.2.0",
+    "lodash.clonedeepwith": "^4.5.0",
+    "lodash.get": "^4.4.2",
     "mkdirp": "^3.0.1"
   },
   "devDependencies": {
@@ -52,6 +55,8 @@
     "@types/chai-as-promised": "^7.1.6",
     "@types/glob": "^8.1.0",
     "@types/js-yaml": "^4.0.6",
+    "@types/lodash.clonedeepwith": "^4.5.9",
+    "@types/lodash.get": "^4.4.9",
     "@types/mocha": "^10.0.2",
     "@types/node": "^20.7.1",
     "@types/sinon": "^17.0.3",

src/config.ts

@@ -1,17 +1,46 @@
-import { existsSync, readFileSync } from 'fs'
+import { existsSync, readFileSync, readdirSync } from 'fs'
+import path from 'path'
 
 import * as defaults from './defaults'
 import type { ContentTypeMap } from './schemas'
 import type { EnvironmentVariables } from './schemas/environmentVariablesSchema'
 
 type HeadersMap = Record<`/${string}`, Record<string, string>>;
 
+interface LanguageConfig {
+  labelsMap: Record<string, unknown>
+  languageId: string
+}
+
 interface RuntimeConfig extends Required<EnvironmentVariables> {
   CONTENT_TYPE_MAP: ContentTypeMap
+  LANGUAGES_CONFIG: LanguageConfig[]
   PUBLIC_HEADERS_MAP: HeadersMap
   USER_PROPERTIES_HEADER_KEY: string | undefined
 }
 
+const validateLanguages = (languageDirPath: string): LanguageConfig[] => {
+  if (!existsSync(languageDirPath)) {
+    return []
+  }
+
+  const languageFilenames = readdirSync(languageDirPath)
+  return languageFilenames.map((filename) => {
+    const filepath = path.join(languageDirPath, filename)
+    const fileContent = JSON.parse(readFileSync(filepath).toString()) as unknown
+    if (!fileContent
+      || typeof fileContent !== 'object'
+      || Array.isArray(fileContent)) {
+      throw new Error(`${filename} is not a valid language configuration`)
+    }
+
+    return {
+      labelsMap: fileContent as Record<string, unknown>,
+      languageId: path.basename(filename, '.json'),
+    }
+  })
+}
+
 const validateContentTypeMap = (contentTypeMap: unknown) => {
   if (contentTypeMap === null || typeof contentTypeMap !== 'object') {
     return defaults.CONTENT_TYPE_MAP
@@ -74,7 +103,10 @@ const getPublicHeadersMap = (input: unknown): HeadersMap => {
 }
 
 const parseConfig = (config: EnvironmentVariables & Record<string, string>): RuntimeConfig => {
-  const { SERVICE_CONFIG_PATH = defaults.SERVICE_CONFIG_PATH } = config
+  const {
+    LANGUAGES_DIRECTORY_PATH = defaults.LANGUAGES_DIRECTORY_PATH,
+    SERVICE_CONFIG_PATH = defaults.SERVICE_CONFIG_PATH,
+  } = config
   let serviceConfig: unknown = defaults.PUBLIC_HEADERS_MAP
 
   let configPath: string | undefined
@@ -103,6 +135,8 @@ const parseConfig = (config: EnvironmentVariables & Record<string, string>): Run
 
   return {
     CONTENT_TYPE_MAP: validateContentTypeMap(contentTypeMap),
+    LANGUAGES_CONFIG: validateLanguages(LANGUAGES_DIRECTORY_PATH),
+    LANGUAGES_DIRECTORY_PATH,
     PUBLIC_DIRECTORY_PATH: config.PUBLIC_DIRECTORY_PATH ?? defaults.PUBLIC_DIRECTORY_PATH,
     PUBLIC_HEADERS_MAP: getPublicHeadersMap(publicHeadersMap),
     RESOURCES_DIRECTORY_PATH: config.RESOURCES_DIRECTORY_PATH ?? defaults.RESOURCES_DIRECTORY_PATH,
@@ -111,5 +145,5 @@ const parseConfig = (config: EnvironmentVariables & Record<string, string>): Run
   }
 }
 
-export type { RuntimeConfig }
+export type { LanguageConfig, RuntimeConfig }
 export { parseConfig }

src/defaults.ts

@@ -4,6 +4,8 @@ const RESOURCES_DIRECTORY_PATH = '/usr/static/configurations'
 
 const PUBLIC_DIRECTORY_PATH = '/usr/static/public'
 
+const LANGUAGES_DIRECTORY_PATH = '/usr/static/languages'
+
 const SERVICE_CONFIG_PATH = '/usr/src/app/config/config.json'
 
 const PUBLIC_HEADERS_MAP = {}
@@ -24,4 +26,5 @@ export {
   SERVICE_CONFIG_PATH,
   PUBLIC_DIRECTORY_PATH,
   PUBLIC_HEADERS_MAP,
+  LANGUAGES_DIRECTORY_PATH,
 }