Add support for WhatsApp media (jpeg/png/gif) bridging (#974)

* Whatsapp image bridging

* Prevent double message in telegram when media with caption received

Co-authored-by: imShara <shara@protonmail.com>

bridge/whatsapp/whatsapp.go

@@ -1,11 +1,14 @@
 package bwhatsapp
 
 import (
+	"bytes"
 	"crypto/rand"
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"mime"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -230,6 +233,66 @@ func (b *Bwhatsapp) JoinChannel(channel config.ChannelInfo) error {
 	return nil
 }
 
+// Post a document message from the bridge to WhatsApp
+func (b *Bwhatsapp) PostDocumentMessage(msg config.Message, filetype string) (string, error) {
+	fi := msg.Extra["file"][0].(config.FileInfo)
+
+	// Post document message
+	message := whatsapp.DocumentMessage{
+		Info: whatsapp.MessageInfo{
+			RemoteJid: msg.Channel,
+		},
+		Title:    fi.Name,
+		FileName: fi.Name,
+		Type:     filetype,
+		Content:  bytes.NewReader(*fi.Data),
+	}
+
+	b.Log.Debugf("=> Sending %#v", msg)
+
+	// create message ID
+	// TODO follow and act if https://github.com/Rhymen/go-whatsapp/issues/101 implemented
+	idBytes := make([]byte, 10)
+	if _, err := rand.Read(idBytes); err != nil {
+		b.Log.Warn(err.Error())
+	}
+
+	message.Info.Id = strings.ToUpper(hex.EncodeToString(idBytes))
+	_, err := b.conn.Send(message)
+
+	return message.Info.Id, err
+}
+
+// Post an image message from the bridge to WhatsApp
+// Handle, for sure image/jpeg, image/png and image/gif MIME types
+func (b *Bwhatsapp) PostImageMessage(msg config.Message, filetype string) (string, error) {
+	fi := msg.Extra["file"][0].(config.FileInfo)
+
+	// Post image message
+	message := whatsapp.ImageMessage{
+		Info: whatsapp.MessageInfo{
+			RemoteJid: msg.Channel,
+		},
+		Type:    filetype,
+		Caption: msg.Username + fi.Comment,
+		Content: bytes.NewReader(*fi.Data),
+	}
+
+	b.Log.Debugf("=> Sending %#v", msg)
+
+	// create message ID
+	// TODO follow and act if https://github.com/Rhymen/go-whatsapp/issues/101 implemented
+	idBytes := make([]byte, 10)
+	if _, err := rand.Read(idBytes); err != nil {
+		b.Log.Warn(err.Error())
+	}
+
+	message.Info.Id = strings.ToUpper(hex.EncodeToString(idBytes))
+	_, err := b.conn.Send(message)
+
+	return message.Info.Id, err
+}
+
 // Send a message from the bridge to WhatsApp
 // Required implementation of the Bridger interface
 // https://github.com/42wim/matterbridge/blob/2cfd880cdb0df29771bf8f31df8d990ab897889d/bridge/bridge.go#L11-L16
@@ -259,18 +322,25 @@ func (b *Bwhatsapp) Send(msg config.Message) (string, error) {
 		// TODO handle edit as a message reply with updated text
 	}
 
-	//// TODO Handle Upload a file
-	//if msg.Extra != nil {
-	//	for _, rmsg := range helper.HandleExtra(&msg, b.General) {
-	//		b.c.SendMessage(roomID, rmsg.Username+rmsg.Text)
-	//	}
-	//	if len(msg.Extra["file"]) > 0 {
-	//		return b.handleUploadFile(&msg, roomID)
-	//	}
-	//}
+	// Handle Upload a file
+	if msg.Extra["file"] != nil {
+		fi := msg.Extra["file"][0].(config.FileInfo)
+		filetype := mime.TypeByExtension(filepath.Ext(fi.Name))
+
+		b.Log.Debugf("Extra file is %#v", filetype)
+
+		// TODO: add different types
+		// TODO: add webp conversion
+		switch filetype {
+		case "image/jpeg", "image/png", "image/gif":
+			return b.PostImageMessage(msg, filetype)
+		default:
+			return b.PostDocumentMessage(msg, filetype)
+		}
+	}
 
 	// Post text message
-	text := whatsapp.TextMessage{
+	message := whatsapp.TextMessage{
 		Info: whatsapp.MessageInfo{
 			RemoteJid: msg.Channel, // which equals to group id
 		},
@@ -281,15 +351,14 @@ func (b *Bwhatsapp) Send(msg config.Message) (string, error) {
 
 	// create message ID
 	// TODO follow and act if https://github.com/Rhymen/go-whatsapp/issues/101 implemented
-	bytes := make([]byte, 10)
-	if _, err := rand.Read(bytes); err != nil {
+	idBytes := make([]byte, 10)
+	if _, err := rand.Read(idBytes); err != nil {
 		b.Log.Warn(err.Error())
 	}
-	text.Info.Id = strings.ToUpper(hex.EncodeToString(bytes))
+	message.Info.Id = strings.ToUpper(hex.EncodeToString(idBytes))
+	_, err := b.conn.Send(message)
 
-	_, err := b.conn.Send(text)
-
-	return text.Info.Id, err
+	return message.Info.Id, err
 }
 
 // TODO do we want that? to allow login with QR code from a bridged channel? https://github.com/tulir/mautrix-whatsapp/blob/513eb18e2d59bada0dd515ee1abaaf38a3bfe3d5/commands.go#L76