package logic

import (
	"context"
	"slowwild/internal/errorx"
	"slowwild/internal/model"
	"slowwild/internal/svc"

	"git.banshen.xyz/huangguangrong/slow_wild_protobuff/slowwild/slowwildserver"

	"slowwild/internal/constants"

	"github.com/spf13/cast"
	"github.com/zeromicro/go-zero/core/logx"
	"gorm.io/gorm"
)

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

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

// 删除帖子
func (l *PostDeleteLogic) PostDelete(in *slowwildserver.PostDeleteReq) (*slowwildserver.PostDeleteRsp, error) {
	// 从context中获取userId
	userId, err := cast.ToInt64E(l.ctx.Value(constants.UserIDKey))
	if err != nil {
		return nil, errorx.ErrInvalidParam
	}

	if in.PostId <= 0 {
		return nil, errorx.ErrInvalidParam
	}

	// 开启事务
	err = l.svcCtx.UserModel.Transaction(l.ctx, func(tx *gorm.DB) error {
		postModel := model.NewPostModel(tx, l.svcCtx.Redis)
		userModel := model.NewUserModel(tx)

		// 获取帖子信息
		post, err := postModel.GetPostDetail(l.ctx, in.PostId)
		if err != nil {
			return err
		}

		// 检查是否是自己的帖子
		if post.UserId != userId {
			return errorx.NewCodeError(20008, "无权删除该帖子")
		}

		// 删除帖子
		if err := postModel.Delete(l.ctx, in.PostId); err != nil {
			return err
		}

		// 减少用户的帖子数
		if err := userModel.DecrementTweetCount(l.ctx, userId); err != nil {
			return err
		}

		// 删除相关缓存
		postModel.ClearCache(l.ctx, in.PostId)

		return nil
	})

	if err != nil {
		l.Logger.Errorf("删除帖子失败: %v", err)
		return nil, errorx.NewCodeError(20009, "删除帖子失败")
	}

	return &slowwildserver.PostDeleteRsp{}, nil
}