from flask import Flask, current_app
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from config import Config
import os
from datetime import datetime
import sqlite3

# Initialize extensions
db = SQLAlchemy()
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.login_message_category = 'info'

def initialize_database(app):
    """Create database tables if they don't exist"""
    with app.app_context():
        try:
            # Create all tables
            db.create_all()
            app.logger.info("Database tables created successfully")
        except Exception as e:
            app.logger.error(f"Error creating database tables: {str(e)}")

def run_migrations(app):
    """Apply any necessary database migrations"""
    db_path = app.config['SQLALCHEMY_DATABASE_URI'].replace('sqlite:///', '')
    
    if not os.path.exists(db_path):
        app.logger.info(f"Database file does not exist: {db_path}")
        return
    
    try:
        conn = sqlite3.connect(db_path)
        cursor = conn.cursor()
        
        # Check if storage_name column exists in file table
        cursor.execute("PRAGMA table_info(file)")
        columns = [column[1] for column in cursor.fetchall()]
        
        if 'storage_name' not in columns:
            app.logger.info("Adding storage_name column to file table")
            cursor.execute("ALTER TABLE file ADD COLUMN storage_name TEXT")
            
            # Update existing records to use filename as storage_name
            cursor.execute("UPDATE file SET storage_name = name WHERE storage_name IS NULL AND is_folder = 0")
            conn.commit()
        
        conn.close()
        app.logger.info("Database migrations completed successfully")
    except sqlite3.OperationalError as e:
        if "no such table: file" in str(e):
            app.logger.info("File table doesn't exist yet, will be created with db.create_all()")
        else:
            app.logger.error(f"Error during migration: {str(e)}")
    except Exception as e:
        app.logger.error(f"Error during migration: {str(e)}")
        
def create_app(config_class=Config):
    app = Flask(__name__)
    app.config.from_object(config_class)
    
    # Initialize extensions
    db.init_app(app)
    login_manager.init_app(app)
    
    # Initialize the upload folder
    os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)
    
    # Auto initialize database if it doesn't exist
    with app.app_context():
        initialize_database(app)
        run_migrations(app)
    
    # Register blueprints
    from app.routes.auth import auth_bp
    from app.routes.files import files_bp
    from app.routes.dashboard import dashboard_bp
    
    app.register_blueprint(auth_bp)
    app.register_blueprint(files_bp)
    app.register_blueprint(dashboard_bp)
    
    # Add context processor for template variables
    @app.context_processor
    def inject_now():
        return {'now': datetime.now()}
    
    return app

from app import models