#!/usr/bin/env python3
"""
Google OAuth Token Refresh Script for VoiceCal.ai

This script automatically refreshes Google OAuth access tokens and updates:
1. Local .env file
2. HuggingFace Spaces secrets
3. Credentials JSON file (if exists)

Designed for cron job execution with logging and email notifications.

Usage:
    python3 scripts/refresh_token_only.py [--notify-email EMAIL] [--verbose]
"""

import requests
import json
import os
import sys
import logging
import argparse
from datetime import datetime, timedelta, timezone
from pathlib import Path


def setup_logging(verbose=False):
    """Setup logging configuration."""
    # Create logs directory if it doesn't exist
    log_dir = Path("logs")
    log_dir.mkdir(exist_ok=True)

    # Create timestamped log file
    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    log_file = log_dir / f"token_refresh_{timestamp}.log"

    # Configure logging
    log_format = "%(asctime)s | %(levelname)s | %(message)s"
    log_level = logging.DEBUG if verbose else logging.INFO

    # Log to both file and console
    logging.basicConfig(
        level=log_level,
        format=log_format,
        handlers=[
            logging.FileHandler(log_file),
            logging.StreamHandler(sys.stdout)
        ]
    )

    return log_file


def load_credentials():
    """Load OAuth credentials from environment variables."""
    logging.info("🔍 Loading OAuth credentials...")

    # Load from .env file if it exists
    env_path = Path(".env")
    if env_path.exists():
        logging.info("📝 Loading from environment variables")
        from dotenv import load_dotenv
        load_dotenv()

    refresh_token = os.environ.get('GOOGLE_REFRESH_TOKEN')
    client_id = os.environ.get('GOOGLE_CLIENT_ID')
    client_secret = os.environ.get('GOOGLE_CLIENT_SECRET')

    if not all([refresh_token, client_id, client_secret]):
        logging.error("❌ Missing required environment variables:")
        logging.error(f"   GOOGLE_REFRESH_TOKEN: {'✓' if refresh_token else '✗'}")
        logging.error(f"   GOOGLE_CLIENT_ID: {'✓' if client_id else '✗'}")
        logging.error(f"   GOOGLE_CLIENT_SECRET: {'✓' if client_secret else '✗'}")
        raise ValueError("Missing required environment variables")

    logging.info("✅ Credentials loaded")
    logging.info(f"   Client ID: {client_id[:20]}...")
    logging.info(f"   Refresh Token: {refresh_token[:20]}...")

    return {
        'refresh_token': refresh_token,
        'client_id': client_id,
        'client_secret': client_secret
    }


def refresh_access_token(credentials):
    """Refresh Google OAuth access token."""
    logging.info("🔄 Refreshing access token...")

    data = {
        'client_id': credentials['client_id'],
        'client_secret': credentials['client_secret'],
        'refresh_token': credentials['refresh_token'],
        'grant_type': 'refresh_token'
    }

    try:
        response = requests.post('https://oauth2.googleapis.com/token', data=data, timeout=30)

        if response.status_code == 200:
            tokens = response.json()
            access_token = tokens['access_token']
            expires_in = tokens.get('expires_in', 3600)

            logging.info("✅ Access token refreshed successfully!")
            logging.info(f"   New token: {access_token[:20]}...")
            logging.info(f"   Expires in: {expires_in} seconds ({expires_in/3600:.1f} hours)")

            return {
                'access_token': access_token,
                'expires_in': expires_in
            }
        else:
            error_msg = f"Token has been expired or revoked." if response.status_code == 400 else response.text
            logging.error(f"❌ Failed to refresh token: {error_msg}")
            logging.error(f"   Response: {response.text if response.text else 'No response'}")
            raise Exception(f"Failed to refresh token: {error_msg}")

    except requests.exceptions.RequestException as e:
        logging.error(f"❌ Network error during token refresh: {e}")
        raise
    except Exception as e:
        logging.error(f"❌ Token refresh failed: {e}")
        raise


def update_env_file(access_token, expiry_seconds):
    """Update .env file with new access token."""
    logging.info("💾 Updating .env file...")

    env_path = Path(".env")
    if not env_path.exists():
        logging.warning("⚠️ .env file not found")
        return False

    # Calculate expiry time using timezone-aware datetime
    expiry_time = datetime.now(timezone.utc) + timedelta(seconds=expiry_seconds)

    # Read current .env file
    with open(env_path, 'r') as f:
        lines = f.readlines()

    # Update token lines
    updated_lines = []
    found_access_token = False
    found_token_expiry = False

    for line in lines:
        if line.startswith('GOOGLE_ACCESS_TOKEN='):
            updated_lines.append(f'GOOGLE_ACCESS_TOKEN={access_token}\n')
            found_access_token = True
        elif line.startswith('GOOGLE_TOKEN_EXPIRY='):
            updated_lines.append(f'GOOGLE_TOKEN_EXPIRY={expiry_time.isoformat()}\n')
            found_token_expiry = True
        else:
            updated_lines.append(line)

    # Add lines if they don't exist
    if not found_access_token:
        updated_lines.append(f'GOOGLE_ACCESS_TOKEN={access_token}\n')
    if not found_token_expiry:
        updated_lines.append(f'GOOGLE_TOKEN_EXPIRY={expiry_time.isoformat()}\n')

    # Write back to .env file
    with open(env_path, 'w') as f:
        f.writelines(updated_lines)

    logging.info("✅ .env file updated")
    return True


def update_credentials_file(access_token, expiry_seconds, credentials):
    """Update Google Calendar credentials JSON file."""
    logging.info("📝 Updating credentials file...")

    creds_path = Path("app/credentials/google_calendar_credentials.json")
    if not creds_path.exists():
        logging.warning(f"⚠️ Credentials file not found: {creds_path}")
        return False

    # Calculate expiry time
    expiry_time = datetime.now(timezone.utc) + timedelta(seconds=expiry_seconds)

    # Load existing credentials
    with open(creds_path, 'r') as f:
        creds_data = json.load(f)

    # Update token and expiry
    creds_data['token'] = access_token
    creds_data['expiry'] = expiry_time.isoformat()

    # Write back to file
    with open(creds_path, 'w') as f:
        json.dump(creds_data, f, indent=2)

    logging.info("✅ Credentials file updated")
    return True


def update_huggingface_secrets(access_token, expiry_seconds):
    """Update HuggingFace Spaces secrets with new OAuth tokens."""
    logging.info("☁️ Updating HuggingFace Spaces secrets...")

    try:
        from huggingface_hub import HfApi

        # Get HF token from environment
        hf_token = os.environ.get("HF_TOKEN")
        if not hf_token:
            logging.warning("⚠️ No HF_TOKEN found - skipping HuggingFace Secrets update")
            return False

        # Initialize HF API
        api = HfApi(token=hf_token)

        # Your space repository ID
        repo_id = "pgits/voiceCal-ai-v3"

        # Calculate expiry time
        expiry_time = datetime.now(timezone.utc) + timedelta(seconds=expiry_seconds)

        # Update access token secret
        api.add_space_secret(
            repo_id=repo_id,
            key="GOOGLE_ACCESS_TOKEN",
            value=access_token
        )
        logging.info("✅ Updated GOOGLE_ACCESS_TOKEN in HF Secrets")

        # Update expiry as ISO string
        api.add_space_secret(
            repo_id=repo_id,
            key="GOOGLE_TOKEN_EXPIRY",
            value=expiry_time.isoformat()
        )
        logging.info("✅ Updated GOOGLE_TOKEN_EXPIRY in HF Secrets")

        logging.info("🎉 HuggingFace Secrets updated successfully!")
        return True

    except ImportError:
        logging.warning("⚠️ huggingface_hub not installed - skipping HF Secrets update")
        return False
    except Exception as e:
        logging.error(f"❌ Failed to update HuggingFace Secrets: {e}")
        return False


def send_email_notification(recipient_email, subject, body):
    """Send email notification using SMTP."""
    try:
        import smtplib
        from email.mime.text import MIMEText
        from email.mime.multipart import MIMEMultipart

        smtp_host = os.environ.get("SMTP_HOST", "smtp.gmail.com")
        smtp_port = int(os.environ.get("SMTP_PORT", "587"))
        smtp_username = os.environ.get("SMTP_USERNAME")
        smtp_password = os.environ.get("SMTP_PASSWORD")

        if not all([smtp_username, smtp_password]):
            logging.warning("⚠️ SMTP credentials not configured - skipping email notification")
            return False

        msg = MIMEMultipart()
        msg['From'] = smtp_username
        msg['To'] = recipient_email
        msg['Subject'] = subject

        msg.attach(MIMEText(body, 'plain'))

        with smtplib.SMTP(smtp_host, smtp_port) as server:
            server.starttls()
            server.login(smtp_username, smtp_password)
            server.send_message(msg)

        logging.info(f"✅ Email notification sent to {recipient_email}")
        return True

    except Exception as e:
        logging.error(f"❌ Failed to send email notification: {e}")
        return False


def main():
    """Main execution function."""
    parser = argparse.ArgumentParser(description='Refresh Google OAuth tokens')
    parser.add_argument('--notify-email', help='Email address for failure notifications')
    parser.add_argument('--verbose', action='store_true', help='Enable verbose logging')
    args = parser.parse_args()

    # Setup logging
    log_file = setup_logging(args.verbose)

    logging.info("=" * 80)
    logging.info("VoiceCal.ai OAuth Token Refresh Script")
    logging.info(f"Started at: {datetime.now(timezone.utc).isoformat()}")
    logging.info(f"Log file: {log_file}")
    logging.info("=" * 80)

    success = False
    error_message = None

    try:
        # Load credentials
        credentials = load_credentials()

        # Refresh access token
        tokens = refresh_access_token(credentials)

        # Update .env file
        update_env_file(tokens['access_token'], tokens['expires_in'])

        # Update credentials file (optional)
        update_credentials_file(tokens['access_token'], tokens['expires_in'], credentials)

        # Update HuggingFace Spaces secrets
        update_huggingface_secrets(tokens['access_token'], tokens['expires_in'])

        success = True

    except Exception as e:
        error_message = str(e)
        logging.error(f"❌ Token refresh failed: {error_message}")

        # Send failure notification if email provided
        if args.notify_email:
            logging.info(f"📧 Sending failure notification to {args.notify_email}...")
            subject = "⚠️ VoiceCal.ai OAuth Token Refresh Failed"
            body = f"""
VoiceCal.ai OAuth token refresh failed.

Error: {error_message}
Timestamp: {datetime.now(timezone.utc).isoformat()}
Log file: {log_file}

Please re-authenticate by visiting:
http://localhost:8080/auth/login

-- VoiceCal.ai Automated Token Refresh
            """.strip()
            send_email_notification(args.notify_email, subject, body)

    # Log completion status
    logging.info("=" * 80)
    logging.info(f"Completed at: {datetime.now(timezone.utc).isoformat()}")
    logging.info(f"Status: {'✅ SUCCESS' if success else '❌ FAILED'}")
    logging.info("=" * 80)

    # Exit with appropriate code
    sys.exit(0 if success else 1)


if __name__ == "__main__":
    main()