import os
from flask import Flask
from flask_migrate import Migrate
from flask_socketio import SocketIO
from dotenv import load_dotenv
from sqlalchemy import text
from .models import db

socketio = SocketIO(cors_allowed_origins="*")
migrate = Migrate()


def create_app():
    load_dotenv()

    app = Flask(__name__)
    app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "dev-secret")
    app.config["SQLALCHEMY_DATABASE_URI"] = os.getenv(
        "DATABASE_URL",
        "postgresql+psycopg2://rezept_finder:rezept_finder@localhost:5432/rezept_finder",
    )
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

    @app.after_request
    def add_cors_headers(response):
        origin = os.getenv("FRONTEND_ORIGIN", "*")
        response.headers["Access-Control-Allow-Origin"] = origin
        response.headers["Access-Control-Allow-Headers"] = "Content-Type"
        response.headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS"
        return response

    db.init_app(app)
    migrate.init_app(app, db)
    socketio.init_app(app, cors_allowed_origins=os.getenv("FRONTEND_ORIGIN", "*"))

    from .routes.sessions import bp as sessions_bp
    app.register_blueprint(sessions_bp, url_prefix="/api/sessions")

    from .socket import events  # noqa: F401

    with app.app_context():
        ensure_schema()

    return app


def ensure_schema():
    db.create_all()
    engine_name = db.engine.url.get_backend_name()
    if engine_name != "postgresql":
        return

    db.session.execute(text(
        "ALTER TABLE session_settings "
        "ADD COLUMN IF NOT EXISTS match_mode VARCHAR(20) NOT NULL DEFAULT 'first_match'"
    ))
    db.session.execute(text(
        "ALTER TABLE session_settings "
        "ADD COLUMN IF NOT EXISTS voting_round INTEGER NOT NULL DEFAULT 1"
    ))
    db.session.commit()