"""
Employee Workstation Activity Tracking - Flask Application Factory

This module provides the application factory function 'create_app' that initializes 
the Flask application with its configuration, database connection, and registered blueprints.
"""
import os
import logging
from logging.handlers import RotatingFileHandler
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from dotenv import load_dotenv

# Initialize SQLAlchemy globally to avoid circular imports
db = SQLAlchemy()

def create_app(test_config=None):
    """Create and configure the Flask application using the factory pattern."""
    
    # Load environment variables
    load_dotenv()  # Try .env first
    config_env_path = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'config.env')
    if os.path.exists(config_env_path):
        load_dotenv(config_env_path)
        print(f"Loaded environment variables from {config_env_path}")
    else:
        print(f"Warning: config.env file not found at {config_env_path}")
    
    # Get the project root directory (parent of app directory)
    project_root = os.path.dirname(os.path.dirname(__file__))
    
    # Create and configure the app with template folder in project root
    app = Flask(__name__, 
                instance_relative_config=True,
                template_folder=os.path.join(project_root, 'templates'),
                static_folder=os.path.join(project_root, 'static'))
    
    # Default configuration
    app.config.from_mapping(
        SECRET_KEY=os.environ.get('SECRET_KEY', 'dev'),
        SQLALCHEMY_DATABASE_URI=os.environ.get('DATABASE_URI', os.environ.get('DATABASE_URL')),
        SQLALCHEMY_TRACK_MODIFICATIONS=False
    )
    
    # Override configuration with test config if provided
    if test_config is not None:
        app.config.update(test_config)
    
    # Ensure DATABASE_URI is set
    if not app.config['SQLALCHEMY_DATABASE_URI']:
        raise ValueError("DATABASE_URI or DATABASE_URL environment variable must be set")
    
    # Ensure the instance folder exists
    try:
        os.makedirs(app.instance_path)
    except OSError:
        pass
    
    # Configure logging
    if not app.debug:  # Avoid duplicate logs in debug mode
        log_formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
        log_handler = RotatingFileHandler(
            os.path.join(app.instance_path, 'server.log'),
            maxBytes=1024 * 1024 * 5,  # 5 MB
            backupCount=5
        )
        log_handler.setFormatter(log_formatter)
        log_handler.setLevel(logging.INFO)
        app.logger.addHandler(log_handler)
        app.logger.setLevel(logging.INFO)
    
    app.logger.info('Flask application starting up...')
    
    # Initialize database with the app
    db.init_app(app)
    
    # Import and register blueprints
    from app.api import events_bp, reports_bp
    app.register_blueprint(events_bp)
    app.register_blueprint(reports_bp)
    
    from app.views.dashboard import views_bp
    app.register_blueprint(views_bp)
    
    # Register error handlers
    from app.errors import register_error_handlers
    register_error_handlers(app)
    
    # Initialize database tables when in development
    @app.cli.command("init-db")
    def init_db_command():
        """Clear existing data and create new tables."""
        with app.app_context():
            db.create_all()
            app.logger.info("Database tables created")
    
    @app.route('/healthcheck')
    def healthcheck():
        return {'status': 'ok'}, 200
    
    return app

def init_db():
    """Initialize the database outside of the CLI context"""
    app = create_app()
    with app.app_context():
        db.create_all()
        app.logger.info("Database initialized")