From 17807d627e8c6aaa62ba8c619c809d1ab1c0f274 Mon Sep 17 00:00:00 2001
From: Ketan Baitule <111437670+ketanbaitule@users.noreply.github.com>
Date: Sat, 6 Jan 2024 15:19:47 +0000
Subject: [PATCH] feat: implemented whatsapp with vonage java

---
 java/whatsapp-with-vonage/.gitignore        |  29 +++++
 java/whatsapp-with-vonage/README.md         | 103 ++++++++++++++++
 java/whatsapp-with-vonage/deps.gradle       |   6 +
 java/whatsapp-with-vonage/src/Main.java     | 130 ++++++++++++++++++++
 java/whatsapp-with-vonage/src/Utils.java    |  46 +++++++
 java/whatsapp-with-vonage/static/index.html |  34 +++++
 6 files changed, 348 insertions(+)
 create mode 100644 java/whatsapp-with-vonage/.gitignore
 create mode 100644 java/whatsapp-with-vonage/README.md
 create mode 100644 java/whatsapp-with-vonage/deps.gradle
 create mode 100644 java/whatsapp-with-vonage/src/Main.java
 create mode 100644 java/whatsapp-with-vonage/src/Utils.java
 create mode 100644 java/whatsapp-with-vonage/static/index.html

diff --git a/java/whatsapp-with-vonage/.gitignore b/java/whatsapp-with-vonage/.gitignore
new file mode 100644
index 00000000..3904a570
--- /dev/null
+++ b/java/whatsapp-with-vonage/.gitignore
@@ -0,0 +1,29 @@
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+replay_pid*
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build
diff --git a/java/whatsapp-with-vonage/README.md b/java/whatsapp-with-vonage/README.md
new file mode 100644
index 00000000..30758ca2
--- /dev/null
+++ b/java/whatsapp-with-vonage/README.md
@@ -0,0 +1,103 @@
+# ⚡ Java WhatsApp Bot with Vonage Function
+
+Simple bot to answer WhatsApp messages.
+
+## 🧰 Usage
+
+### GET /
+
+HTML form for interacting with the function.
+
+### POST /
+
+Receives a message, validates its signature, and sends a response back to the sender.
+
+**Parameters**
+
+| Name          | Description                        | Location | Type                | Sample Value         |
+| ------------- | ---------------------------------- | -------- | ------------------- | -------------------- |
+| Content-Type  | Content type of the request        | Header   | `application/json ` | N/A                  |
+| Authorization | Webhook signature for verification | Header   | String              | `Bearer <signature>` |
+| from          | Sender's identifier.               | Body     | String              | `12345`              |
+| text          | Text content of the message.       | Body     | String              | `Hello!`             |
+
+> All parameters are coming from Vonage webhook. Exact documentation can be found in [Vonage API Docs](https://developer.vonage.com/en/api/messages-olympus#inbound-message).
+
+**Response**
+
+Sample `200` Response:
+
+```json
+{
+  "ok": true
+}
+```
+
+Sample `400` Response:
+
+```json
+{
+  "ok": false,
+  "error": "Missing required parameter: from"
+}
+```
+
+Sample `401` Response:
+
+```json
+{
+  "ok": false,
+  "error": "Payload hash mismatch."
+}
+```
+
+## ⚙️ Configuration
+
+| Setting           | Value           |
+|-------------------|-----------------|
+| Runtime           | Java (18)       |
+| Entrypoint        | `src/Main.java` |
+| Permissions       | `any`           |
+| Timeout (Seconds) | 15              |
+
+## 🔒 Environment Variables
+
+### VONAGE_API_KEY
+
+API Key to use the Vonage API.
+
+| Question      | Answer                                                                                                                   |
+| ------------- | ------------------------------------------------------------------------------------------------------------------------ |
+| Required      | Yes                                                                                                                      |
+| Sample Value  | `62...97`                                                                                                                |
+| Documentation | [Vonage: Q&A](https://api.support.vonage.com/hc/en-us/articles/204014493-How-do-I-find-my-Voice-API-key-and-API-secret-) |
+
+### VONAGE_API_SECRET
+
+Secret to use the Vonage API.
+
+| Question      | Answer                                                                                                                   |
+| ------------- | ------------------------------------------------------------------------------------------------------------------------ |
+| Required      | Yes                                                                                                                      |
+| Sample Value  | `Zjc...5PH`                                                                                                              |
+| Documentation | [Vonage: Q&A](https://api.support.vonage.com/hc/en-us/articles/204014493-How-do-I-find-my-Voice-API-key-and-API-secret-) |
+
+### VONAGE_API_SIGNATURE_SECRET
+
+Secret to verify the webhooks sent by Vonage.
+
+| Question      | Answer                                                                                                         |
+| ------------- | -------------------------------------------------------------------------------------------------------------- |
+| Required      | Yes                                                                                                            |
+| Sample Value  | `NXOi3...IBHDa`                                                                                                |
+| Documentation | [Vonage: Webhooks](https://developer.vonage.com/en/getting-started/concepts/webhooks#decoding-signed-webhooks) |
+
+### VONAGE_WHATSAPP_NUMBER
+
+Vonage WhatsApp number to send messages from.
+
+| Question      | Answer                                                                                                                        |
+| ------------- | ----------------------------------------------------------------------------------------------------------------------------- |
+| Required      | Yes                                                                                                                           |
+| Sample Value  | `+14000000102`                                                                                                                |
+| Documentation | [Vonage: Q&A](https://api.support.vonage.com/hc/en-us/articles/4431993282580-Where-do-I-find-my-WhatsApp-Number-Certificate-) |
diff --git a/java/whatsapp-with-vonage/deps.gradle b/java/whatsapp-with-vonage/deps.gradle
new file mode 100644
index 00000000..6387741a
--- /dev/null
+++ b/java/whatsapp-with-vonage/deps.gradle
@@ -0,0 +1,6 @@
+dependencies {
+    implementation 'com.google.code.gson:gson:2.9.0'
+    implementation 'io.jsonwebtoken:jjwt-api:0.12.3'
+    implementation 'io.jsonwebtoken:jjwt-gson:0.12.3'
+    runtimeOnly 'io.jsonwebtoken:jjwt-impl:0.12.3'
+}
\ No newline at end of file
diff --git a/java/whatsapp-with-vonage/src/Main.java b/java/whatsapp-with-vonage/src/Main.java
new file mode 100644
index 00000000..0eb829ec
--- /dev/null
+++ b/java/whatsapp-with-vonage/src/Main.java
@@ -0,0 +1,130 @@
+package io.openruntimes.java.src;
+
+import io.openruntimes.java.RuntimeContext;
+import io.openruntimes.java.RuntimeOutput;
+
+import java.util.Map;
+import java.util.HashMap;
+
+import com.google.gson.Gson;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.http.HttpRequest;
+import java.net.http.HttpClient;
+import java.net.http.HttpResponse;
+
+import java.io.IOException;
+
+import java.util.Base64;
+
+import io.jsonwebtoken.Jwts;
+import io.jsonwebtoken.JwtException;
+import io.jsonwebtoken.security.Keys;
+import io.jsonwebtoken.Jws;
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.gson.io.GsonDeserializer;
+
+import javax.crypto.SecretKey;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.nio.charset.StandardCharsets;
+
+import java.util.Map;
+import java.util.HashMap;
+
+public class Main {
+
+    public RuntimeOutput main(RuntimeContext context) throws Exception {
+        String reqVariables[] = {
+            "VONAGE_API_KEY",
+            "VONAGE_API_SECRET",
+            "VONAGE_API_SIGNATURE_SECRET",
+            "VONAGE_WHATSAPP_NUMBER"
+        };
+        Utils.throw_if_missing(System.getenv(), reqVariables);
+
+        if (context.getReq().getMethod().equals("GET")) {
+            return context.getRes().send("Got GET Request");
+        }
+
+        Gson gson = new Gson();
+        Map<String, Object> responseMap = new HashMap<String, Object>();
+        responseMap.put("ok", true); 
+
+        Map<String, Object> body;
+        if(context.getReq().getBody() instanceof Map){
+            body  = (Map<String, Object>)context.getReq().getBody();
+        }else{
+            responseMap.put("ok", false); 
+            responseMap.put("error", "Invalid Body.");
+            return context.getRes().json(responseMap, 400);
+        }
+        Map<String, String> headers = context.getReq().getHeaders();
+
+        try {
+            String token = (headers.get("authorization") != null && !headers.get("authorization").isEmpty()) ? headers.get("authorization").split(" ")[1] : "";
+			SecretKey key = Keys.hmacShaKeyFor(System.getenv("VONAGE_API_SIGNATURE_SECRET").getBytes());
+			Jws<Claims> decoded = Jwts.parser().json(new GsonDeserializer(gson)).setSigningKey(key).build().parseClaimsJws(token);
+
+            try{
+                MessageDigest digest = MessageDigest.getInstance("SHA-256");
+                byte[] hashBytes = digest.digest(context.getReq().getBodyRaw().getBytes(StandardCharsets.UTF_8));
+                StringBuilder hexStringBuilder = new StringBuilder();
+                for (byte b : hashBytes) {
+                    hexStringBuilder.append(String.format("%02x", b));
+                }
+
+                if(!decoded.getBody().get("payload_hash").equals(hexStringBuilder.toString())){
+                    responseMap.put("ok", false);
+                    responseMap.put("error", "Payload hash mismatch.");
+                    return context.getRes().json(responseMap, 401);
+                }
+            }catch(NoSuchAlgorithmException e){
+                responseMap.put("ok", false);
+                responseMap.put("error", "Payload hash mismatch.");
+                return context.getRes().json(responseMap, 401);
+            }
+		}catch (JwtException e) {
+			responseMap.put("ok", false);
+            responseMap.put("error", "Invalid Token");
+            return context.getRes().json(responseMap, 401);
+		}
+        try{
+            String reqHeader[] = {"from", "text"};
+            Utils.throw_if_missing(body, reqHeader);
+        }catch(Exception e){
+            responseMap.put("ok", false); 
+            responseMap.put("error", e.getMessage());
+            return context.getRes().json(responseMap, 400);
+        }
+        
+        try{
+			Map<String, String> data = new HashMap<String, String>();
+			data.put("from", System.getenv("VONAGE_WHATSAPP_NUMBER"));
+			data.put("to", System.getenv("TO_NUMBER"));
+			data.put("message_type", "text");
+			data.put("text", "Hi there! You sent me: "+body.get("text"));
+			data.put("channel", "whatsapp");
+	
+			String basicAuth= System.getenv("VONAGE_API_KEY") + ":" + System.getenv("VONAGE_API_SECRET");
+			String basicAuthToken = "Basic " + Base64.getEncoder().encodeToString(basicAuth.getBytes());
+			
+			HttpRequest request = HttpRequest.newBuilder()
+				.uri(new URI("https://messages-sandbox.nexmo.com/v1/messages"))
+				.header("Content-Type", "application/json")
+				.header("Accept", "application/json")
+				.header("Authorization", basicAuthToken)
+				.POST(HttpRequest.BodyPublishers.ofString(gson.toJson(data)))
+				.build();
+
+			HttpResponse<String> response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());
+			
+		}catch(URISyntaxException | IOException | InterruptedException e){
+			responseMap.put("ok", false); 
+            responseMap.put("error", e.getMessage());
+            return context.getRes().json(responseMap, 400);
+		}
+        return context.getRes().json(responseMap);
+    }
+}
diff --git a/java/whatsapp-with-vonage/src/Utils.java b/java/whatsapp-with-vonage/src/Utils.java
new file mode 100644
index 00000000..e6753f63
--- /dev/null
+++ b/java/whatsapp-with-vonage/src/Utils.java
@@ -0,0 +1,46 @@
+package io.openruntimes.java.src;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.List;
+import java.util.ArrayList;
+
+public class Utils {
+    /**
+     * Returns the contents of a file in the static folder
+     *
+     * @param fileName The name of the file
+     * @return Contents of static/{fileName}
+     * @throws IOException If an I/O error occurs reading from the file
+     */
+    public static String getStaticFile(String fileName) throws IOException {
+        Path staticFolder = Paths.get("../static/");
+        Path filePath = staticFolder.resolve(fileName);
+        List<String> lines = Files.readAllLines(filePath);
+        return String.join("\n", lines);
+    }
+
+    /**
+     * Throws an error if any of the keys are missing from the map
+     *
+     * @param map  The map to check for missing keys
+     * @param keys The array of keys to check for
+     * @throws Exception If any required fields are missing
+     */
+    public static void throw_if_missing(Map<String, ?> map, String[] keys) throws Exception {
+        List<String> missing = new ArrayList<String>();
+        for (String key : keys) {
+            if (!map.containsKey(key) || map.get(key) == null) {
+                missing.add(key);
+            }
+        }
+        if(missing.size() > 0){
+            throw new Exception("Missing required fields: "+String.join(", ", missing));
+        }
+    }
+}
diff --git a/java/whatsapp-with-vonage/static/index.html b/java/whatsapp-with-vonage/static/index.html
new file mode 100644
index 00000000..3852090f
--- /dev/null
+++ b/java/whatsapp-with-vonage/static/index.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>WhatsApp Bot with Vonage</title>
+
+    <link rel="stylesheet" href="https://unpkg.com/@appwrite.io/pink" />
+    <link rel="stylesheet" href="https://unpkg.com/@appwrite.io/pink-icons" />
+  </head>
+  <body>
+    <main class="main-content">
+      <div class="top-cover u-padding-block-end-56">
+        <div class="container">
+          <div
+            class="u-flex u-gap-16 u-flex-justify-center u-margin-block-start-16"
+          >
+            <h1 class="heading-level-1">WhatsApp Bot with Vonage</h1>
+            <code class="u-un-break-text"></code>
+          </div>
+          <p
+            class="body-text-1 u-normal u-margin-block-start-8"
+            style="max-width: 50rem"
+          >
+            This function listens to incoming webhooks from Vonage regarding
+            WhatsApp messages, and responds to them. To use the function, send
+            message to the WhatsApp user provided by Vonage.
+          </p>
+        </div>
+      </div>
+    </main>
+  </body>
+</html>