# -*- coding: utf-8 -*-
"""迁移脚本：为非空邮箱补充唯一索引。"""
import logging
from sqlalchemy import text
from insurance.db.compat import db


def migrate():
    """创建 wecom_user_mapping.email 非空唯一索引。"""
    try:
        from sqlalchemy import inspect

        inspector = inspect(db.engine)
        if not inspector.has_table("wecom_user_mapping"):
            logging.info("wecom_user_mapping 表不存在，跳过邮箱唯一索引")
            return

        user_columns = {col["name"] for col in inspector.get_columns("wecom_user_mapping")}
        if "email" not in user_columns:
            logging.info("wecom_user_mapping.email 字段不存在，跳过邮箱唯一索引")
            return

        index_names = {idx["name"] for idx in inspector.get_indexes("wecom_user_mapping")}
        if "idx_wecom_user_mapping_email_unique" in index_names:
            logging.info("邮箱唯一索引已存在，跳过创建")
            return

        duplicate_email = db.session.execute(text("""
            SELECT email
            FROM wecom_user_mapping
            WHERE email IS NOT NULL AND email <> ''
            GROUP BY email
            HAVING COUNT(*) > 1
            LIMIT 1
        """)).fetchone()
        if duplicate_email:
            logging.warning(
                "wecom_user_mapping 存在重复邮箱 %s，跳过邮箱唯一索引创建",
                duplicate_email[0],
            )
            return

        db.session.execute(text("""
            CREATE UNIQUE INDEX IF NOT EXISTS idx_wecom_user_mapping_email_unique
            ON wecom_user_mapping (email)
            WHERE email IS NOT NULL AND email <> ''
        """))
        db.session.commit()
        logging.info("成功创建 wecom_user_mapping.email 唯一索引")
    except Exception as e:
        logging.error("创建邮箱唯一索引失败: %s", e)
        db.session.rollback()
        raise


def downgrade():
    """删除邮箱唯一索引。"""
    try:
        db.session.execute(text("DROP INDEX IF EXISTS idx_wecom_user_mapping_email_unique"))
        db.session.commit()
    except Exception as e:
        logging.error("删除邮箱唯一索引失败: %s", e)
        db.session.rollback()
        raise