To ensure that the quoted message is forwarded correctly without duplicating it in the destination channel, follow these steps:

Steps:

1. Forward the original message first:

   • When a new message arrives, check if it quotes another message.

   • If it does, ensure the quoted message is forwarded first.

   • Track the message IDs in both source and destination channels to maintain the context.

2. Maintain a mapping of message IDs:

   • Use a dictionary to store the mapping between the source message ID and the corresponding message ID in the destination channels.

   • This mapping will be used to reference the correct message when forwarding the quoted message.

3. Check for existing messages:

   • Before forwarding a new message, check if the quoted message already exists in the destination channels.

   • If it exists, use the existing message ID to create the quote reference.

4. Forward or Quote Messages:

   • If the quoted message does not exist in the destination channel, forward it first.

   • Use the mapped message ID to set thereply_to argument when forwarding the message with the quote.

import requests;
import time

# Replace with your bot token

BOT_TOKEN = '12345'
API_URL = f'https://api.telegram.org/bot%7BBOT_TOKEN%7D'

# Replace with the chat ID of the source and destination channels

SOURCE_CHANNEL_ID = -12345  # Use negative ID for channels
DESTINATION_CHANNEL_IDS = [-12345, -12345]  # Use negative ID for channels

auto_forward = False
forwarded_messages = {}

def get_updates(offset=None):
"""Get updates from the Telegram API."""
url = f'{API_URL}/getUpdates'
params = {'timeout': 100, 'offset': offset}
response = requests.get(url, params=params)
result_json = response.json()['result']
return result_json

def send_message(chat_id, text):
"""Send a text message to a channel."""
url = f'{API_URL}/sendMessage'
data = {'chat_id': chat_id, 'text': text}
response = requests.post(url, data=data)
return response.json()

def forward_message(chat_id, from_chat_id, message_id, reply_to_message_id=None):
"""Forward a message to a channel with optional reply context."""
url = f'{API_URL}/copyMessage'
data = {
'chat_id': chat_id,
'from_chat_id': from_chat_id,
'message_id': message_id
}
if reply_to_message_id:
data['reply_to_message_id'] = reply_to_message_id

    response = requests.post(url, data=data)
    return response.json()

def main():
"""Main function to run the bot."""
global auto_forward
update_id = None

    while True:
        updates = get_updates(offset=update_id)
    
        for update in updates:
            if 'update_id' in update:
                update_id = update['update_id'] + 1
    
            if 'message' in update:
                message = update['message']
                chat_id = message['chat']['id']
                text = message.get('text', '')
    
                if text == '/start' and not auto_forward:
                    auto_forward = True
                    send_message(chat_id, "Auto-forwarding started.")
                elif text == '/stop' and auto_forward:
                    auto_forward = False
                    send_message(chat_id, "Auto-forwarding stopped.")
    
            if auto_forward and 'channel_post' in update and update['channel_post']['chat']['id'] == SOURCE_CHANNEL_ID:
                channel_post = update['channel_post']
                message_id = channel_post['message_id']
                reply_to_message = channel_post.get('reply_to_message', None)
    
                if message_id in forwarded_messages:
                    continue
    
                quoted_message_id = None
                forwarded_quoted_message_ids = {}
    
                if reply_to_message:
                    quoted_message_id = reply_to_message.get('message_id')
                    quoted_message_text = reply_to_message.get('text')
                    print(f"Quoted Message ID: {quoted_message_id}", quoted_message_text)
    
                for dest_channel_id in DESTINATION_CHANNEL_IDS:
                    if reply_to_message:
                        # Forward the quoted message first if it exists and hasn't been forwarded yet
                        if quoted_message_id and dest_channel_id not in forwarded_quoted_message_ids:
                            result_quoted = forward_message(
                                chat_id=dest_channel_id,
                                from_chat_id=SOURCE_CHANNEL_ID,
                                message_id=quoted_message_id
                            )
                            if result_quoted['ok']:
                                forwarded_quoted_message_ids[dest_channel_id] = result_quoted['result']['message_id']
                                print(f"Successfully forwarded quoted message to {dest_channel_id}.")
                            else:
                                print(f"Failed to forward quoted message to {dest_channel_id}. Error: {result_quoted.get('description')}")
    
                    # Forward the main message quoting the already forwarded quoted message
                    if dest_channel_id in forwarded_quoted_message_ids:
                        result_main = forward_message(
                            chat_id=dest_channel_id,
                            from_chat_id=SOURCE_CHANNEL_ID,
                            message_id=message_id,
                            reply_to_message_id=forwarded_quoted_message_ids[dest_channel_id]
                        )
                    else:
                        result_main = forward_message(
                            chat_id=dest_channel_id,
                            from_chat_id=SOURCE_CHANNEL_ID,
                            message_id=message_id
                        )
    
                    if result_main['ok']:
                        print(f"Successfully forwarded main message to {dest_channel_id}.")
                    else:
                        print(f"Failed to forward main message to {dest_channel_id}. Error: {result_main.get('description')}")
    
                forwarded_messages[message_id] = True
    
        time.sleep(1)

if __name__ == '__main__':
main()