import os
import logging

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import text

from config import Config

logger = logging.getLogger(__name__)
db = SQLAlchemy()


def create_app(config_class=Config):
    app = Flask(__name__)
    app.config.from_object(config_class)

    # Ensure upload directories exist
    os.makedirs(app.config["PHOTO_FOLDER"], exist_ok=True)
    os.makedirs(app.config["QR_FOLDER"], exist_ok=True)
    os.makedirs(app.config["LOGO_FOLDER"], exist_ok=True)
    os.makedirs(os.path.dirname(app.config["SQLALCHEMY_DATABASE_URI"].replace("sqlite:///", "")), exist_ok=True)

    db.init_app(app)

    from app.routes import main_bp
    app.register_blueprint(main_bp)

    with app.app_context():
        db.create_all()
        _migrate_existing_data(app)
        _create_default_users(app)

    return app


def _column_exists(table_name, column_name):
    return db.session.execute(
        text(f"SELECT COUNT(*) FROM pragma_table_info('{table_name}') WHERE name='{column_name}'")
    ).scalar()


def _add_column_if_missing(table_name, column_name, column_def):
    if not _column_exists(table_name, column_name):
        db.session.execute(text(f"ALTER TABLE {table_name} ADD COLUMN {column_name} {column_def}"))


def _migrate_existing_data(app):
    """Миграция существующих гостей в дефолтное мероприятие и добавление новых колонок."""
    from app.models import Event, Guest

    try:
        # Добавляем колонки дизайна билета в таблицу events
        _add_column_if_missing("events", "ticket_title", "VARCHAR(255)")
        _add_column_if_missing("events", "ticket_subtitle", "VARCHAR(255)")
        _add_column_if_missing("events", "ticket_body_text", "TEXT")
        _add_column_if_missing("events", "ticket_background_color", "VARCHAR(7) DEFAULT '#ffffff'")
        _add_column_if_missing("events", "ticket_text_color", "VARCHAR(7) DEFAULT '#000000'")
        _add_column_if_missing("events", "ticket_accent_color", "VARCHAR(7) DEFAULT '#0d6efd'")
        _add_column_if_missing("events", "ticket_show_qr", "BOOLEAN DEFAULT 1")
        _add_column_if_missing("events", "ticket_show_photo", "BOOLEAN DEFAULT 0")
        _add_column_if_missing("events", "ticket_layout", "VARCHAR(20) DEFAULT 'portrait'")
        _add_column_if_missing("events", "logo_filename", "VARCHAR(255)")

        # Добавляем колонки ФИО/телефона в таблицу guests
        _add_column_if_missing("guests", "last_name", "VARCHAR(255)")
        _add_column_if_missing("guests", "first_name", "VARCHAR(255)")
        _add_column_if_missing("guests", "middle_name", "VARCHAR(255)")
        _add_column_if_missing("guests", "phone", "VARCHAR(50)")

        # Проверяем, есть ли колонка event_id в таблице guests
        if _column_exists("guests", "event_id"):
            db.session.commit()
            return  # Миграция гостей уже выполнена

        # Создаём дефолтное мероприятие для существующих гостей
        default_event = Event(
            name=app.config.get("DEFAULT_EVENT_NAME", "Архивное мероприятие"),
            description="Автоматически созданное мероприятие для существующих гостей",
            is_active=True,
        )
        db.session.add(default_event)
        db.session.flush()

        # Добавляем колонку event_id
        db.session.execute(text("ALTER TABLE guests ADD COLUMN event_id INTEGER REFERENCES events(id)"))

        # Привязываем всех существующих гостей к дефолтному мероприятию
        db.session.execute(
            text("UPDATE guests SET event_id = :event_id"),
            {"event_id": default_event.id},
        )

        # Добавляем колонку event_id в check_ins (опционально)
        if not _column_exists("check_ins", "event_id"):
            db.session.execute(text("ALTER TABLE check_ins ADD COLUMN event_id INTEGER REFERENCES events(id)"))
            db.session.execute(
                text("""
                    UPDATE check_ins
                    SET event_id = (
                        SELECT event_id FROM guests WHERE guests.id = check_ins.guest_id
                    )
                """)
            )

        db.session.commit()
        logger.info(f"Migration completed: existing guests moved to event '{default_event.name}' (id={default_event.id})")
    except Exception as e:
        db.session.rollback()
        logger.warning(f"Migration skipped or failed: {e}")


def _create_default_users(app):
    """Создание начальных пользователей, если в базе нет ни одного."""
    from app.models import User

    try:
        if User.query.first() is not None:
            return

        admin = User(
            username=app.config.get("ADMIN_USERNAME", "admin"),
            role="admin",
            is_active=True,
        )
        admin.set_password(app.config.get("ADMIN_PASSWORD", "admin"))

        staff = User(
            username=app.config.get("STAFF_USERNAME", "staff"),
            role="staff",
            is_active=True,
        )
        staff.set_password(app.config.get("STAFF_PASSWORD", "staff"))

        db.session.add(admin)
        db.session.add(staff)
        db.session.commit()

        if app.config.get("ADMIN_PASSWORD") == "admin" or app.config.get("STAFF_PASSWORD") == "staff":
            logger.warning("Default users created with default passwords. Change them in production!")
        else:
            logger.info("Default users 'admin' and 'staff' created from environment variables.")
    except Exception as e:
        db.session.rollback()
        logger.warning(f"Default users creation skipped or failed: {e}")