"""Alembic 迁移环境：从应用配置读取 DATABASE_URL 并连接 Base.metadata。

用法（cd backend）：
    uv run alembic revision --autogenerate -m "add xxx table"
    uv run alembic upgrade head
"""

from __future__ import annotations

from logging.config import fileConfig

from alembic import context
from app.core.config import get_settings
from app.infrastructure.persistence.sqlalchemy.base import Base
from sqlalchemy import engine_from_config, pool

config = context.config

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

config.set_main_option("sqlalchemy.url", get_settings().database_url)

target_metadata = Base.metadata


def run_migrations_offline() -> None:
    """离线模式：只生成 SQL，不连接数据库。"""
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
        render_as_batch=True,  # SQLite 支持 ALTER 需要 batch 模式
    )

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


def run_migrations_online() -> None:
    """在线模式：连接数据库执行迁移。"""
    connectable = engine_from_config(
        config.get_section(config.config_ini_section, {}),
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    with connectable.connect() as connection:
        context.configure(
            connection=connection,
            target_metadata=target_metadata,
            render_as_batch=True,
        )

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


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