"""
Alembic migration environment.

Wires Alembic's autogenerate feature to the app's actual SQLAlchemy Base
(app/db/models.py) and reads the DB URL from the app's own Settings
rather than duplicating it in alembic.ini — one source of truth for the
connection string.
"""

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 async_engine_from_config

from app.core.config import get_settings
from app.db.models import Base

config = context.config

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

target_metadata = Base.metadata

settings = get_settings()
config.set_main_option("sqlalchemy.url", settings.DATABASE_URL)


def run_migrations_offline() -> None:
    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:
    context.configure(connection=connection, target_metadata=target_metadata)
    with context.begin_transaction():
        context.run_migrations()


async def run_migrations_online() -> None:
    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()


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