from flask import Flask, request, abort
from linebot import LineBotApi, WebhookHandler
from linebot.exceptions import InvalidSignatureError
from linebot.models import MessageEvent, TextMessage, TextSendMessage
from google.cloud import translate_v2 as translate

# Initialize Flask app
app = Flask(__name__)

# Initialize LINE bot with your credentials
line_bot_api = LineBotApi('YOUR_CHANNEL_ACCESS_TOKEN')
handler = WebhookHandler('YOUR_CHANNEL_SECRET')

# Initialize Google Translate client
translate_client = translate.Client()

# Define the webhook endpoint
@app.route("/webhook", methods=['POST'])
def webhook():
    # Get the signature from the request header
    signature = request.headers['X-Line-Signature']
    # Get the request body as text
    body = request.get_data(as_text=True)

    # Verify the signature
    try:
        handler.handle(body, signature)
    except InvalidSignatureError:
        abort(400)  # Return 400 if signature is invalid

    return 'OK'

# Handle incoming text messages
@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    # Extract the original message text
    original_text = event.message.text

    # Translate the text to English (auto-detects source language)
    translation = translate_client.translate(original_text, target_language='en')
    translated_text = translation['translatedText']

    # Format the reply message
    reply_message = f"Translation: {translated_text}"

    # Send the translated message back to the channel
    line_bot_api.reply_message(
        event.reply_token,
        TextSendMessage(text=reply_message)
    )

# Run the Flask app
if __name__ == "__main__":
    app.run(host='0.0.0.0', port=5000)