"""
viewer_server.py — Application Entrypoint

This file was refactored from a 2800-line monolith into a clean entrypoint.
All business logic has been moved to the `backend/` package:

    backend/
    ├── __init__.py        ← App Factory (create_app)
    ├── config.py          ← All config & environment variables
    ├── api/               ← Flask Blueprints (routes/controllers)
    │   ├── auth.py
    │   ├── books.py
    │   ├── payment.py
    │   ├── translate.py
    │   ├── epub.py
    │   └── developer.py
    ├── services/          ← Business logic layer
    │   ├── auth_service.py
    │   ├── book_service.py
    │   ├── payment_service.py
    │   ├── email_service.py
    │   ├── epub_service.py
    │   └── translation.py
    ├── database/
    │   └── db_manager.py  ← DB connections, circuit breaker, caches
    ├── core/
    │   ├── security.py    ← JWT, bcrypt helpers
    │   ├── decorators.py  ← @jwt_required, @require_api_key_auth
    │   └── rate_limit.py  ← IP rate limiters
    └── workers/
        └── email_worker.py ← Background IMAP/Gmail email polling

To run the server:
    python viewer_server.py
Or with gunicorn:
    gunicorn -w 4 -b 0.0.0.0:5051 "viewer_server:app"
"""

import logging
import sys
import traceback
from flask import jsonify

from backend.core.logger import setup_logger
logger = setup_logger("server")

from backend import create_app

app = create_app()

@app.errorhandler(Exception)
def handle_exception(e):
    """Global unhandled exception handler to output clean JSON in production."""
    # Log the complete stack trace
    error_msg = f"Unhandled exception encountered: {str(e)}"
    stack_trace = traceback.format_exc()
    logger.error(error_msg)
    logger.error(stack_trace)
    
    # Trigger asynchronous alert email to Admin
    try:
        from backend.services.alert_service import send_alert_to_admin
        subject = f"Lỗi nghiêm trọng (500 Internal Error): {str(e)[:50]}"
        body = f"Đã xảy ra lỗi chưa xử lý trên server:<br><strong>Lỗi:</strong> {str(e)}<br><br><strong>Stack Trace:</strong><br>{stack_trace.replace(chr(10), '<br>')}"
        send_alert_to_admin("critical_error", subject, body)
    except Exception as alert_err:
        logger.error(f"Failed to trigger alert email for exception: {alert_err}")
    
    # Return JSON response instead of HTML traceback page
    return jsonify({
        "error": "Internal Server Error. Please contact administrator.",
        "success": False
    }), 500

@app.route("/api/temp-db-fix", methods=["GET"])
def temp_db_fix():
    from flask import request
    secret = request.args.get("secret")
    if secret != "super_secret_db_fix_2026":
        return "Unauthorized", 403
    
    import os
    import psycopg2
    url = os.environ.get("DATABASE_URL")
    if not url:
        return "DATABASE_URL environment variable is missing", 500
        
    logs = []
    try:
        conn = psycopg2.connect(url)
        cursor = conn.cursor()
        
        # 1. Clean up user 75
        tables_to_clean = [
            "refresh_tokens", "bookshelf", "reading_history", "password_reset_tokens", 
            "api_keys", "api_usage", "translation_history", "vocabulary", 
            "user_settings", "usage_tracking", "personal_notifications", "login_history"
        ]
        for tbl in tables_to_clean:
            try:
                cursor.execute(f"DELETE FROM {tbl} WHERE user_id = 75")
                logs.append(f"✔ Cleaned {tbl} for user_id = 75")
            except Exception as e:
                logs.append(f"ℹ Could not clean {tbl} for user_id = 75: {e}")
                
        try:
            cursor.execute("DELETE FROM users WHERE id = 75")
            logs.append("✔ Deleted user 75 from users table")
        except Exception as e:
            logs.append(f"❌ Failed to delete user 75: {e}")
            
        # 2. Link VIP user congkx123789 to Gmail
        cursor.execute("SELECT id, username, email, vip_status FROM users WHERE username = %s OR id = 100", ("congkx123789",))
        vip_user = cursor.fetchone()
        if vip_user:
            vip_id = vip_user[0]
            cursor.execute("""
                UPDATE users 
                SET email = %s, 
                    google_id = NULL,
                    email_verified = 1 
                WHERE id = %s
            """, ("havucong25@gmail.com", vip_id))
            logs.append(f"✔ Linked VIP user {vip_user[1]} (ID {vip_id}) to havucong25@gmail.com")
        else:
            logs.append("❌ VIP user congkx123789 not found in database")
            
        conn.commit()
        conn.close()
        return jsonify({"success": True, "logs": logs})
    except Exception as e:
        return jsonify({"success": False, "error": str(e), "logs": logs})

if __name__ == "__main__":
    logger.info("🚀 Server đang khởi động tại: http://localhost:5051")
    app.run(host="0.0.0.0", port=5051, debug=False, threaded=True)