# app/__init__.py

import click
from flask import Flask
from flask.cli import with_appcontext
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from werkzeug.middleware.proxy_fix import ProxyFix
from sqlalchemy import event
from sqlalchemy.engine import Engine
import sqlite3

db = SQLAlchemy()
migrate = Migrate()


# =============================================================================
# CLI Commands
# =============================================================================

@click.command("version-check")
@with_appcontext
def version_check_command():
    """Check app version and run data migrations if needed (e.g., phash recomputation)."""
    from app.utils.version_migration import check_and_run_migrations
    check_and_run_migrations()

@event.listens_for(Engine, "connect")
def set_sqlite_pragma(dbapi_connection, connection_record):
    # Only apply to SQLite connections
    if isinstance(dbapi_connection, sqlite3.Connection):
        cursor = dbapi_connection.cursor()
        cursor.execute("PRAGMA foreign_keys = ON")
        cursor.close()

def create_app(config_class='config.Config'):
    app = Flask(__name__)
    app.config.from_object(config_class)
    app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
        "pool_pre_ping": True
    }

    db.init_app(app)
    migrate.init_app(app, db)

    app.wsgi_app = ProxyFix(app.wsgi_app, x_for=1, x_proto=1, x_host=1, x_port=1)

    from app.main import main
    app.register_blueprint(main)

    @app.template_filter('datetimeformat')
    def datetimeformat(value, format="%Y-%m-%d"):
        return value.strftime(format) if value else ""

    # Register CLI commands
    app.cli.add_command(version_check_command)

    return app