"""
Alembic 环境配置。
"""
from logging.config import fileConfig
import os
import sys

from sqlalchemy import engine_from_config
from sqlalchemy import pool

from alembic import context

# 将父目录添加到路径以进行导入
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(__file__))))

# 从项目根目录加载 .env（从 alembic 目录向上 3 级）
from dotenv import load_dotenv
project_root = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(__file__)))))
env_path = os.path.join(project_root, '.env')
load_dotenv(env_path)

from app.config import Settings
from app.db.models import Base

# 这是 Alembic 配置对象
config = context.config

# 为 Python 日志解释配置文件
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# 加载设置并设置数据库 URL
settings = Settings()
config.set_main_option("sqlalchemy.url", settings.database_url)

# 为 'autogenerate' 支持添加模型的 MetaData 对象
target_metadata = Base.metadata


def run_migrations_offline() -> None:
    """
    在 'offline' 模式下运行迁移。
    """
    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 run_migrations_online() -> None:
    """
    在 'online' 模式下运行迁移。
    """
    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
        )

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


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