package logic

import (
	"context"

	"slowwild/internal/svc"

	"git.banshen.xyz/huangguangrong/slow_wild_protobuff/slowwild/slowwildserver"
	"github.com/zeromicro/go-zero/core/logx"
	"gorm.io/gorm"

	"slowwild/internal/errorx"
	"slowwild/internal/model"
)

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

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

// 关注用户
func (l *UserFollowLogic) UserFollow(in *slowwildserver.FollowUserReq) (*slowwildserver.FollowUserRes, error) {
	if in.UserId <= 0 || in.FollowUserId <= 0 {
		return nil, errorx.ErrInvalidParam
	}

	// 检查是否已经关注
	followMap, err := l.svcCtx.UserFollowModel.CheckMutualFollows(l.ctx, in.UserId, []int64{in.FollowUserId})
	if err != nil {
		return nil, errorx.ErrUserQueryFailed
	}
	if followMap[in.FollowUserId] {
		return nil, errorx.NewCodeError(10010, "已经关注该用户")
	}

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

		// 创建关注关系
		err := userFollowModel.Follow(l.ctx, in.UserId, in.FollowUserId)
		if err != nil {
			return err
		}

		// 增加当前用户的关注数
		err = userModel.IncrementFollowCount(l.ctx, in.UserId)
		if err != nil {
			return err
		}

		// 增加目标用户的粉丝数
		err = userModel.IncrementFansCount(l.ctx, in.FollowUserId)
		if err != nil {
			return err
		}

		return nil
	})

	if err != nil {
		l.Logger.Errorf("关注用户失败: %v", err)
		return nil, errorx.NewCodeError(10011, "关注用户失败")
	}

	return &slowwildserver.FollowUserRes{}, nil
}