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

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

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
    Config.init_app(app)
    
    # Auto initialize database if it doesn't exist
    with app.app_context():
        initialize_database(app)
        run_migrations(app)
    
    # Register blueprints
    from app.routes import auth_bp, files_bp, 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

def initialize_database(app):
    """Create database tables if they don't exist."""
    db_path = app.config['SQLALCHEMY_DATABASE_URI'].replace('sqlite:///', '')
    
    # Check if database file exists
    if not os.path.exists(db_path):
        print("Database does not exist. Creating tables...")
        db.create_all()
        
        # Import models here to avoid circular imports
        from app.models import User
        
        # Create admin user if it doesn't exist
        admin = User.query.filter_by(username='admin').first()
        if not admin:
            admin = User(username='admin')
            admin.set_password('admin')  # Change this in production
            db.session.add(admin)
            db.session.commit()
            print("Admin user created.")

def run_migrations(app):
    """Run any needed database migrations."""
    db_path = app.config['SQLALCHEMY_DATABASE_URI'].replace('sqlite:///', '')
    conn = sqlite3.connect(db_path)
    cursor = conn.cursor()
    
    try:
        # Check for missing columns in File table
        cursor.execute("PRAGMA table_info(file)")
        columns = [column[1] for column in cursor.fetchall()]
        
        # Add storage_name column if missing
        if 'storage_name' not in columns:
            print("Running migration: Adding storage_name column to file table...")
            cursor.execute("ALTER TABLE file ADD COLUMN storage_name TEXT")
            
            # Update existing files to use name as storage_name
            cursor.execute("UPDATE file SET storage_name = name WHERE is_folder = 0")
            
            conn.commit()
            print("Migration completed successfully!")
    except Exception as e:
        print(f"Migration error: {e}")
    finally:
        conn.close()

from app import models