"""
Quality App v2 - Flask Application Factory
Robust, modular application with login, dashboard, and multiple modules
"""
from flask import Flask
from flask_session import Session
from datetime import datetime, timedelta
import os
import logging
from logging.handlers import RotatingFileHandler


def create_app(config=None):
    """
    Application factory function
    Creates and configures the Flask application
    """
    app = Flask(__name__)
    
    # Load configuration
    if config is None:
        from app.config import Config
        config = Config
    
    app.config.from_object(config)
    
    # Setup logging
    setup_logging(app)
    logger = logging.getLogger(__name__)
    logger.info("=" * 80)
    logger.info("Flask App Initialization Started")
    logger.info("=" * 80)
    
    # Configure session
    app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(hours=8)
    app.config['SESSION_COOKIE_SECURE'] = False  # Set True in production with HTTPS
    app.config['SESSION_COOKIE_HTTPONLY'] = True
    app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'
    app.config['SESSION_COOKIE_NAME'] = 'quality_app_session'
    app.config['SESSION_REFRESH_EACH_REQUEST'] = True
    
    # Use filesystem for session storage (works with multiple gunicorn workers)
    sessions_dir = os.path.join(app.config.get('LOG_DIR', '/app/data/logs'), '..', 'sessions')
    os.makedirs(sessions_dir, exist_ok=True)
    app.config['SESSION_TYPE'] = 'filesystem'
    app.config['SESSION_FILE_DIR'] = sessions_dir
    app.config['SESSION_FILE_THRESHOLD'] = 500
    
    # Initialize Flask-Session
    Session(app)
    
    # Initialize database connection
    logger.info("Initializing database connection...")
    from app.database import init_db, close_db
    init_db(app)
    app.teardown_appcontext(close_db)
    
    # Register blueprints
    logger.info("Registering blueprints...")
    register_blueprints(app)
    
    # Register error handlers
    logger.info("Registering error handlers...")
    register_error_handlers(app)
    
    # Add template globals
    app.jinja_env.globals['now'] = datetime.now
    
    # Add context processor for app name
    @app.context_processor
    def inject_app_settings():
        """Inject app settings into all templates"""
        try:
            from app.database import get_db
            conn = get_db()
            cursor = conn.cursor()
            cursor.execute(
                "SELECT setting_value FROM application_settings WHERE setting_key = %s",
                ('app_name',)
            )
            result = cursor.fetchone()
            cursor.close()
            app_name = result[0] if result else 'Quality App v2'
        except:
            app_name = 'Quality App v2'
        
        return {'app_name': app_name}
    
    # Add before_request handlers
    register_request_handlers(app)
    
    # Initialize backup scheduler
    logger.info("Initializing backup scheduler...")
    try:
        from app.scheduler import init_scheduler
        init_scheduler(app)
    except Exception as e:
        logger.error(f"Failed to initialize backup scheduler: {e}")
    
    logger.info("=" * 80)
    logger.info("Flask App Initialization Completed Successfully")
    logger.info("=" * 80)
    
    return app



def setup_logging(app):
    """Configure application logging"""
    log_dir = app.config.get('LOG_DIR', '/app/data/logs')
    
    # Create log directory if it doesn't exist
    if not os.path.exists(log_dir):
        os.makedirs(log_dir, exist_ok=True)
    
    # Configure rotating file handler
    log_file = os.path.join(log_dir, 'app.log')
    handler = RotatingFileHandler(
        log_file,
        maxBytes=10485760,  # 10MB
        backupCount=10
    )
    
    # Create formatter
    formatter = logging.Formatter(
        '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )
    handler.setFormatter(formatter)
    
    # Set logging level
    log_level = app.config.get('LOG_LEVEL', 'INFO')
    handler.setLevel(getattr(logging, log_level))
    
    # Add handler to app logger
    app.logger.addHandler(handler)
    app.logger.setLevel(getattr(logging, log_level))


def register_blueprints(app):
    """Register application blueprints"""
    from app.routes import main_bp
    from app.modules.quality.routes import quality_bp
    from app.modules.settings.routes import settings_bp
    from app.modules.warehouse.routes import warehouse_bp
    from app.modules.warehouse.boxes_routes import boxes_bp
    
    app.register_blueprint(main_bp)
    app.register_blueprint(quality_bp, url_prefix='/quality')
    app.register_blueprint(settings_bp, url_prefix='/settings')
    app.register_blueprint(warehouse_bp, url_prefix='/warehouse')
    app.register_blueprint(boxes_bp)
    
    app.logger.info("Blueprints registered: main, quality, settings, warehouse, boxes")


def register_error_handlers(app):
    """Register error handlers"""
    
    @app.errorhandler(404)
    def page_not_found(e):
        from flask import render_template
        return render_template('errors/404.html'), 404
    
    @app.errorhandler(500)
    def internal_error(e):
        from flask import render_template
        app.logger.error(f"Internal error: {e}")
        return render_template('errors/500.html'), 500
    
    @app.errorhandler(403)
    def forbidden(e):
        from flask import render_template
        return render_template('errors/403.html'), 403


def register_request_handlers(app):
    """Register before/after request handlers"""
    
    @app.before_request
    def before_request():
        """Handle pre-request logic"""
        from flask import session, request, redirect, url_for
        
        # Skip authentication check for login and static files
        if request.endpoint and (
            request.endpoint in ['static', 'main.login', 'main.index'] or
            request.path.startswith('/static/')
        ):
            return None
        
        # Check if user is logged in
        if 'user_id' not in session:
            return redirect(url_for('main.login'))
        
        return None
    
    @app.after_request
    def after_request(response):
        """Handle post-request logic"""
        return response