import requests
from typing import Dict, Any, Optional
from app.providers.base import BaseProvider
from app.core.config import settings
import logging

logger = logging.getLogger(__name__)

class TelegramProvider(BaseProvider):
    """
    Telegram Bot API provider for testing.
    
    Setup:
    1. Talk to @BotFather on Telegram
    2. Create new bot with /newbot
    3. Copy the bot token
    4. Set TELEGRAM_BOT_TOKEN in .env
    5. Start a chat with your bot
    6. Use your Telegram user ID as the phone number in contacts
    
    To get your Telegram user ID:
    - Message @userinfobot on Telegram
    - OR use https://api.telegram.org/bot<TOKEN>/getUpdates after messaging your bot
    """
    
    def __init__(self):
        self.bot_token = settings.TELEGRAM_BOT_TOKEN
        self.base_url = f"https://api.telegram.org/bot{self.bot_token}"
    
    def send_message(
        self,
        to: str,
        template_name: Optional[str],
        template_body: str,
        variables: Dict[str, str],
        language: str = "en"
    ) -> str:
        """
        Send a message via Telegram Bot API.
        
        Args:
            to: Telegram user ID or chat ID (stored in phone_e164 field)
            template_name: Ignored for Telegram (no template system)
            template_body: Message text with variables like {{first_name}}
            variables: Dict of variables to replace in template_body
            language: Ignored for Telegram
        
        Returns:
            message_id: Telegram message ID as string
        """
        # Replace variables in template
        message_text = template_body
        for key, value in variables.items():
            message_text = message_text.replace(f"{{{{{key}}}}}", value)
        
        # Prepare request
        url = f"{self.base_url}/sendMessage"
        payload = {
            "chat_id": to,
            "text": message_text,
            "parse_mode": "HTML"  # Support basic formatting
        }
        
        logger.info(f"Sending Telegram message to chat_id: {to}")
        
        try:
            response = requests.post(url, json=payload, timeout=10)
            
            # Get response body for debugging
            result = response.json()
            
            if not response.ok or not result.get("ok"):
                error_desc = result.get("description", "Unknown error")
                error_code = result.get("error_code", 0)
                logger.error(f"Telegram API error {error_code}: {error_desc}")
                logger.error(f"Request payload: {payload}")
                raise Exception(f"Telegram API error {error_code}: {error_desc}")
            
            message_id = str(result["result"]["message_id"])
            logger.info(f"Telegram message sent successfully. Message ID: {message_id}")
            
            return message_id
            
        except requests.exceptions.RequestException as e:
            logger.error(f"Telegram API request failed: {str(e)}")
            raise Exception(f"Failed to send Telegram message: {str(e)}")
    
    def get_provider_name(self) -> str:
        return "telegram"