"""Alembic environment configuration

说明：
- DataMate Python 服务使用异步 SQLAlchemy（mysql+aiomysql）。
- 为了让 `alembic upgrade head` 开箱即用，这里自动从 `settings.database_url`
  注入 `sqlalchemy.url`，无需在 alembic.ini 手工维护。
"""

from __future__ import annotations

import asyncio
import os
import sys
from logging.config import fileConfig

from alembic import context
from sqlalchemy import pool
from sqlalchemy.ext.asyncio import async_engine_from_config

# 添加项目路径（runtime/datamate-python）
sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))

from app.core.config import settings
from app.db.session import Base
from app.db.models import *  # noqa: F401,F403

config = context.config

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

# 自动注入 sqlalchemy.url（优先使用 settings.database_url）
if not config.get_main_option("sqlalchemy.url"):
    config.set_main_option("sqlalchemy.url", settings.database_url)

target_metadata = Base.metadata


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode."""
    url = config.get_main_option("sqlalchemy.url")
    if not url:
        raise RuntimeError("alembic 未配置 sqlalchemy.url，且无法从 settings.database_url 推导")

    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) -> None:
    context.configure(connection=connection, target_metadata=target_metadata)

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


async def run_async_migrations() -> 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()


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()