"""Alembic env.py — 支持 async Postgres。"""

import asyncio
from logging.config import fileConfig

from sqlalchemy import pool
from sqlalchemy.engine import Connection
from sqlalchemy.ext.asyncio import async_engine_from_config

from alembic import context

# Alembic Config
config = context.config

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

# 导入所有模型以注册 metadata
import sys
import os

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "backend"))
from app.config import get_settings
from app.models import Task, Event, Thought, Todo  # noqa
from app.db import Base

target_metadata = Base.metadata
settings = get_settings()

# Alembic 默认回退到本地配置，但运行时优先使用 Settings / DATABASE_URL。
config.set_main_option("sqlalchemy.url", settings.database_url_sync)


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode."""
    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_async_migrations() -> None:
    """Run migrations in 'online' mode with async engine."""
    config_section = config.get_section(config.config_ini_section, {})
    config_section["sqlalchemy.url"] = settings.database_url

    connectable = async_engine_from_config(
        config_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()