"""Alembic 迁移环境配置 — 异步引擎 + 自动加载模型"""
import asyncio
from logging.config import fileConfig

from alembic import context
from sqlalchemy.ext.asyncio import create_async_engine

from app.core.config import settings
from app.models import Base  # 自动发现所有 SQLAlchemy 模型

# Alembic Config 对象
config = context.config

# 日志配置
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# 将 DATABASE_URL 同步到 alembic 配置中（覆盖 alembic.ini 中的占位值）
config.set_main_option("sqlalchemy.url", settings.DATABASE_URL)

# 自动生成迁移时需要的 models 元数据
target_metadata = Base.metadata


def run_migrations_offline() -> None:
    """离线模式：生成 SQL 脚本而非直接执行"""
    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):
    """在线模式：通过数据库连接执行迁移"""
    context.configure(connection=connection, target_metadata=target_metadata)
    with context.begin_transaction():
        context.run_migrations()


async def run_migrations_online() -> None:
    """在线模式：异步引擎"""
    connectable = create_async_engine(
        config.get_main_option("sqlalchemy.url"),
        echo=settings.DEBUG,
    )
    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())