"""Module with Alembic configuration."""

import asyncio
from logging.config import fileConfig

from alembic import context
from config import PostgreSQLSettings
from sqlalchemy import pool
from sqlalchemy.engine import Connection
from sqlalchemy.ext.asyncio import async_engine_from_config
from src.infrastructure.models import Base

config = context.config
database_config = PostgreSQLSettings()

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

target_metadata = Base.metadata

DSN = '{driver}://{user}:{password}@{host}:{port}/{name}'.format(
    driver=database_config.db_driver,
    user=database_config.db_user,
    password=database_config.db_password,
    host=database_config.db_host,
    port=database_config.db_port,
    name=database_config.db_name,
)

config.set_main_option('sqlalchemy.url', DSN)


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option('sqlalchemy.url')
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={'paramstyle': 'named'},
    )

    with context.begin_transaction():
        context.run_migrations()


def do_run_migrations(connection: Connection) -> None:
    """Do migrations.

    Args:
        connection (Connection): Connection to Database.
    """
    context.configure(connection=connection, target_metadata=target_metadata)

    with context.begin_transaction():
        context.run_migrations()


async def run_async_migrations() -> None:
    """In this scenario we need to create an Engine.

    And associate a connection with the context.
    """
    connectable = async_engine_from_config(
        config.get_section(config.config_ini_section, {}),
        prefix='sqlalchemy.',
        poolclass=pool.NullPool,
    )

    async with connectable.connect() as connection:
        await connection.run_sync(do_run_migrations)

    await connectable.dispose()


def run_migrations_online() -> None:
    """Run migrations in 'online' mode."""
    asyncio.run(run_async_migrations())


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