import os
import click
from datetime import timedelta
from flask import Flask
from dotenv import load_dotenv
from flask_migrate import Migrate
from flask_jwt_extended import JWTManager
from flask_cors import CORS

from models import db, bcrypt, User
from celery_app import celery # Import celery instance

def create_app():
    """Application Factory Pattern"""
    load_dotenv()
    app = Flask(__name__)

    # --- Configuration ---
    app.config.from_mapping(
        SQLALCHEMY_DATABASE_URI=os.environ.get('DATABASE_URL'),
        SQLALCHEMY_ENGINE_OPTIONS={
            'pool_recycle': 3600,
            'pool_size': 20,
            'max_overflow': 30,
            'pool_pre_ping': True,
            'pool_timeout': 30
        },
        JWT_SECRET_KEY=os.environ.get('JWT_SECRET_KEY'),
        SQLALCHEMY_TRACK_MODIFICATIONS=False,
        JWT_ACCESS_TOKEN_EXPIRES=timedelta(days=2),
        CELERY_BROKER_URL=os.environ.get('CELERY_BROKER_URL', 'redis://localhost:6379/0'),
        CELERY_RESULT_BACKEND=os.environ.get('CELERY_RESULT_BACKEND', 'redis://localhost:6379/0'),
        DIFY_API_BASE_URL=os.environ.get("DIFY_API_BASE_URL"),
        DIFY_STT_API_KEY=os.environ.get("DIFY_STT_API_KEY"),
        DIFY_TRANSLATOR_API_KEY=os.environ.get("DIFY_TRANSLATOR_API_KEY"),
        DIFY_SUMMARIZER_API_KEY=os.environ.get("DIFY_SUMMARIZER_API_KEY"),
        DIFY_ACTION_EXTRACTOR_API_KEY=os.environ.get("DIFY_ACTION_EXTRACTOR_API_KEY"),
        # LDAP Configuration
        LDAP_SERVER=os.environ.get('LDAP_SERVER', 'panjit.com.tw'),
        LDAP_PORT=int(os.environ.get('LDAP_PORT', 389)),
        LDAP_USE_SSL=os.environ.get('LDAP_USE_SSL', 'False').lower() == 'true',
        LDAP_BIND_USER_DN=os.environ.get('LDAP_BIND_USER_DN', ''),
        LDAP_BIND_USER_PASSWORD=os.environ.get('LDAP_BIND_USER_PASSWORD', ''),
        LDAP_SEARCH_BASE=os.environ.get('LDAP_SEARCH_BASE', 'DC=panjit,DC=com,DC=tw'),
        LDAP_USER_LOGIN_ATTR=os.environ.get('LDAP_USER_LOGIN_ATTR', 'userPrincipalName')
    )

    project_root = os.path.dirname(os.path.abspath(__file__))
    UPLOAD_FOLDER = os.path.join(project_root, 'uploads')
    if not os.path.exists(UPLOAD_FOLDER):
        os.makedirs(UPLOAD_FOLDER)
    app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
    app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024 * 1024  # 1GB upload limit

    # --- Initialize Extensions ---
    db.init_app(app)
    bcrypt.init_app(app)
    Migrate(app, db)
    JWTManager(app)
    CORS(app)

    # --- Configure Celery ---
    celery.conf.update(app.config)
    # This custom Task class ensures tasks run with the Flask app context
    class ContextTask(celery.Task):
        def __call__(self, *args, **kwargs):
            with app.app_context():
                return self.run(*args, **kwargs)
    celery.Task = ContextTask

    # --- Import and Register Blueprints ---
    from auth_routes import auth_bp
    from api_routes import api_bp
    from ai_routes import ai_bp
    from action_item_routes import action_bp
    app.register_blueprint(auth_bp)
    app.register_blueprint(api_bp)
    app.register_blueprint(ai_bp)
    app.register_blueprint(action_bp)

    # --- Static File Serving (for Single Container) ---
    from flask import send_from_directory, send_file

    # Serve React build files
    @app.route('/')
    def serve_frontend():
        try:
            return send_file(os.path.join(app.root_path, 'frontend/dist/index.html'))
        except:
            return "AI Meeting Assistant is running. Frontend build not found."

    @app.route('/<path:path>')
    def serve_static(path):
        # Try to serve static files first
        try:
            return send_from_directory(os.path.join(app.root_path, 'frontend/dist'), path)
        except:
            # If not found, serve index.html for SPA routing
            try:
                return send_file(os.path.join(app.root_path, 'frontend/dist/index.html'))
            except:
                return "File not found", 404

    # --- CLI Commands ---
    @app.cli.command("create_admin")
    @click.argument("username")
    @click.argument("password")
    def create_admin(username, password):
        """Creates a new admin user."""
        with app.app_context():
            try:
                if User.query.filter_by(username=username).first():
                    print(f"Error: User '{username}' already exists.")
                    return
                admin_user = User(username=username, role='admin')
                admin_user.set_password(password)
                db.session.add(admin_user)
                db.session.commit()
                print(f"Admin user '{username}' created successfully.")
            except Exception as e:
                db.session.rollback()
                print(f"An error occurred: {e}")

    return app

app = create_app()

if __name__ == '__main__':
    port = int(os.environ.get("FLASK_RUN_PORT", 5000))
    app.run(host='0.0.0.0', port=port, debug=True)