import asyncio
from logging.config import fileConfig

from alembic import context
from sqlalchemy import pool
from sqlalchemy.engine import Connection
from sqlalchemy.ext.asyncio import create_async_engine

from lead_scoring.config import Settings
from lead_scoring.db import Base

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# add your model's MetaData object here
# for 'autogenerate' support
target_metadata = Base.metadata


def get_database_url() -> str:
    attr_url = config.attributes.get("sqlalchemy_url")
    if attr_url:
        return str(attr_url)
    opt_url = config.get_main_option("sqlalchemy.url")
    if opt_url:
        return opt_url
    return Settings().database_url


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode."""
    url = get_database_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:
    context.configure(connection=connection, target_metadata=target_metadata)

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


async def run_async_migrations() -> None:
    """Run migrations in async engine scenario."""
    url = get_database_url()
    connectable = create_async_engine(
        url,
        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."""
    connectable = config.attributes.get("connection", None)

    if connectable is not None:
        do_run_migrations(connectable)
    else:
        asyncio.run(run_async_migrations())


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