package dept

import (
	"context"
	"fmt"

	authHelper "perms-system-server/internal/logic/auth"
	"perms-system-server/internal/response"
	"perms-system-server/internal/svc"
	"perms-system-server/internal/types"

	"github.com/zeromicro/go-zero/core/logx"
	"github.com/zeromicro/go-zero/core/stores/sqlx"
)

type DeleteDeptLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewDeleteDeptLogic(ctx context.Context, svcCtx *svc.ServiceContext) *DeleteDeptLogic {
	return &DeleteDeptLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *DeleteDeptLogic) DeleteDept(req *types.DeleteDeptReq) error {
	if err := authHelper.RequireSuperAdmin(l.ctx); err != nil {
		return err
	}

	return l.svcCtx.SysDeptModel.TransactCtx(l.ctx, func(ctx context.Context, session sqlx.Session) error {
		// 行锁锁定目标部门，防止并发删除/修改
		var deptId int64
		lockQuery := fmt.Sprintf("SELECT `id` FROM %s WHERE `id` = ? FOR UPDATE", l.svcCtx.SysDeptModel.TableName())
		if err := session.QueryRowCtx(ctx, &deptId, lockQuery, req.Id); err != nil {
			return response.ErrNotFound("部门不存在")
		}

		var childCount int64
		countChildQuery := fmt.Sprintf("SELECT COUNT(*) FROM %s WHERE `parentId` = ?", l.svcCtx.SysDeptModel.TableName())
		if err := session.QueryRowCtx(ctx, &childCount, countChildQuery, req.Id); err != nil {
			return err
		}
		if childCount > 0 {
			return response.ErrBadRequest("该部门下存在子部门，无法删除")
		}

		var userCount int64
		countUserQuery := fmt.Sprintf("SELECT COUNT(*) FROM %s WHERE `deptId` = ?", l.svcCtx.SysUserModel.TableName())
		if err := session.QueryRowCtx(ctx, &userCount, countUserQuery, req.Id); err != nil {
			return err
		}
		if userCount > 0 {
			return response.ErrBadRequest("该部门下仍有关联用户，无法删除")
		}

		return l.svcCtx.SysDeptModel.DeleteWithTx(ctx, session, req.Id)
	})
}