feat: new media download way

src/controllers/messageController.js

@@ -1,6 +1,7 @@
 const { MessageMedia, Location, Poll } = require('whatsapp-web.js')
+const { Readable } = require('stream')
 const { sessions } = require('../sessions')
-const { sendErrorResponse } = require('../utils')
+const { sendErrorResponse, decodeBase64 } = require('../utils')
 
 /**
  * Get message by its ID from a given chat using the provided client.
@@ -116,6 +117,7 @@ const downloadMedia = async (req, res) => {
     const client = sessions.get(req.params.sessionId)
     const message = await _getMessageById(client, messageId, chatId)
     if (!message) { throw new Error('Message not found') }
+    if (!message.hasMedia) { throw new Error('Message media not found') }
     const messageMedia = await message.downloadMedia()
     res.json({ success: true, messageMedia })
   } catch (error) {
@@ -123,6 +125,54 @@ const downloadMedia = async (req, res) => {
   }
 }
 
+/**
+ * Downloads media from a message and sends it as binary data.
+ * @async
+ * @function
+ * @param {Object} req - The request object.
+ * @param {Object} res - The response object.
+ * @param {string} req.params.sessionId - The session ID.
+ * @param {string} req.body.messageId - The message ID.
+ * @param {string} req.body.chatId - The chat ID.
+ * @returns {Promise<void>} - A Promise that resolves with no value when the function completes.
+ */
+const downloadMediaAsData = async (req, res) => {
+  /*
+    #swagger.summary = 'Download attached message media as binary data'
+  */
+  try {
+    const { messageId, chatId } = req.body
+    const client = sessions.get(req.params.sessionId)
+    const message = await _getMessageById(client, messageId, chatId)
+    if (!message) { throw new Error('Message not found') }
+    if (!message.hasMedia) { throw new Error('Message media not found') }
+    const { data, mimetype, filename, filesize } = await message.downloadMedia()
+    /* #swagger.responses[200] = {
+        description: 'Binary data.'
+      }
+    */
+    res.writeHead(200, {
+      ...(mimetype && { 'Content-Type': mimetype }),
+      ...(filesize && { 'Content-Length': filesize }),
+      ...(filename && { 'Content-Disposition': `attachment; filename=${encodeURIComponent(filename)}` })
+    })
+    const readableStream = new Readable({
+      read () {
+        for (const chunk of decodeBase64(data)) {
+          this.push(chunk)
+        }
+        this.push(null)
+      }
+    })
+    readableStream.on('end', () => {
+      res.end()
+    })
+    readableStream.pipe(res)
+  } catch (error) {
+    sendErrorResponse(res, 500, error.message)
+  }
+}
+
 /**
  * Forwards a message to a destination chat.
  * @async
@@ -684,6 +734,7 @@ module.exports = {
   getClassInfo,
   deleteMessage,
   downloadMedia,
+  downloadMediaAsData,
   forward,
   getInfo,
   getMentions,

src/routes.js

@@ -170,6 +170,7 @@ routes.use('/message', messageRouter)
 messageRouter.post('/getClassInfo/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.getClassInfo)
 messageRouter.post('/delete/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.deleteMessage)
 messageRouter.post('/downloadMedia/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.downloadMedia)
+messageRouter.post('/downloadMediaAsData/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.downloadMediaAsData)
 messageRouter.post('/forward/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.forward)
 messageRouter.post('/getInfo/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.getInfo)
 messageRouter.post('/getMentions/:sessionId', [middleware.sessionNameValidation, middleware.sessionValidation], messageController.getMentions)

src/utils.js

@@ -51,10 +51,19 @@ const sendMessageSeenStatus = async (message) => {
   }
 }
 
+const decodeBase64 = function * (base64String) {
+  const chunkSize = 1024
+  for (let i = 0; i < base64String.length; i += chunkSize) {
+    const chunk = base64String.slice(i, i + chunkSize)
+    yield Buffer.from(chunk, 'base64')
+  }
+}
+
 module.exports = {
   triggerWebhook,
   sendErrorResponse,
   waitForNestedObject,
   checkIfEventisEnabled,
-  sendMessageSeenStatus
+  sendMessageSeenStatus,
+  decodeBase64
 }