import logging
from datetime import datetime, timedelta
from typing import List, Dict, Any
from sqlalchemy.orm import Session

from backend.models import User

logger = logging.getLogger(__name__)


class AdminService:
    """管理员服务"""

    @staticmethod
    def approval_warning_for_user(
        user: User, allow_unverified_email: bool = False, next_email: str | None = None
    ) -> Dict[str, Any] | None:
        from backend.services.email_settings_service import EmailSettingsService

        email_changed = next_email is not None and next_email != user.email
        has_verified_email = bool(user.email and user.email_verified_at and not email_changed)
        should_warn = (
            EmailSettingsService.should_warn_unverified_email_before_approval()
            and not has_verified_email
        )
        if should_warn and not allow_unverified_email:
            return {
                "success": False,
                "message": "用户邮箱未验证，确认后仍可继续审批",
                "requires_override": True,
                "warning_code": "UNVERIFIED_EMAIL",
            }
        if should_warn:
            return {"warning_code": "UNVERIFIED_EMAIL"}
        return None

    @staticmethod
    def get_pending_users(db: Session) -> List[User]:
        """获取待审批用户列表"""
        users = (
            db.query(User)
            .filter(User.is_approved == False, User.role == "user")
            .order_by(User.created_at.desc())
            .all()
        )

        return users

    @staticmethod
    def approve_user(
        user_id: int, db: Session, allow_unverified_email: bool = False
    ) -> Dict[str, Any]:
        """审批通过用户"""
        user = db.query(User).filter(User.id == user_id).first()

        if not user:
            return {"success": False, "message": "用户不存在"}

        if user.is_approved:
            return {"success": False, "message": "用户已经通过审批"}

        warning = AdminService.approval_warning_for_user(user, allow_unverified_email)
        if warning and warning.get("requires_override"):
            return warning

        user.is_approved = True
        user.updated_at = datetime.now()
        db.commit()

        logger.info(f"管理员审批通过用户: {user.alias} (ID: {user.id})")

        result = {"success": True, "message": "审批成功", "user_id": user.id}
        if warning and warning.get("warning_code"):
            result["warning_code"] = warning["warning_code"]
        return result

    @staticmethod
    def reject_user(user_id: int, db: Session) -> Dict[str, Any]:
        """拒绝并删除用户"""
        user = db.query(User).filter(User.id == user_id).first()

        if not user:
            return {"success": False, "message": "用户不存在"}

        alias = user.alias
        db.delete(user)
        db.commit()

        logger.info(f"管理员拒绝用户: {alias} (ID: {user_id})")

        return {"success": True, "message": "已拒绝并删除用户"}

    @staticmethod
    def delete_expired_pending_users(db: Session) -> int:
        """删除24小时未审批的用户"""
        cutoff_time = datetime.now() - timedelta(hours=24)

        expired_users = (
            db.query(User)
            .filter(User.is_approved == False, User.role == "user", User.created_at < cutoff_time)
            .all()
        )

        count = len(expired_users)

        for user in expired_users:
            logger.info(f"删除过期未审批用户: {user.alias} (ID: {user.id})")
            db.delete(user)

        db.commit()

        return count