import os
import sys
from logging.config import fileConfig
from sqlalchemy import pool, create_engine
from alembic import context

# Přidání backend do sys.path pro správný import
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from app.core.db import Base

config = context.config
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

target_metadata = Base.metadata

DATABASE_URL = os.getenv("DATABASE_URL")
if not DATABASE_URL:
    # fallback na synchronní url pro Alembic (používá sync driver)
    mariadb_host = os.getenv("MARIADB_HOST", "localhost")
    mariadb_port = os.getenv("MARIADB_PORT", "3306")
    mariadb_db = os.getenv("MARIADB_DB", "group_project")
    mariadb_user = os.getenv("MARIADB_USER", "root")
    mariadb_password = os.getenv("MARIADB_PASSWORD", "strongpassword")
    DATABASE_URL = f"mysql+pymysql://{mariadb_user}:{mariadb_password}@{mariadb_host}:{mariadb_port}/{mariadb_db}"

# Vždy používej synchronní engine pro migrace
SYNC_DATABASE_URL = DATABASE_URL.replace("+asyncmy", "+pymysql")


def run_migrations_offline() -> None:
    context.configure(
        url=SYNC_DATABASE_URL,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )
    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online() -> None:
    connectable = create_engine(SYNC_DATABASE_URL, poolclass=pool.NullPool)
    with connectable.connect() as connection:
        context.configure(
            connection=connection,
            target_metadata=target_metadata,
        )
        with context.begin_transaction():
            context.run_migrations()


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()