slow_wild_backend/internal/model/post_action_model.go

package model

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"
	"time"

	"github.com/go-redis/redis/v8"
	"gorm.io/gorm"
)

// PPostAction 冒泡/文章动作
type PostAction struct {
	*Model
	PostId     int64 `json:"post_id" gorm:"post_id"`         // POST ID
	UserId     int64 `json:"user_id" gorm:"user_id"`         // 用户ID
	ActionType int8  `json:"action_type" gorm:"action_type"` // 对帖子的动作0-点赞1-收藏2-分享
}

// TableName 表名称
func (*PostAction) TableName() string {
	return "p_post_action"
}

// MessageModel 消息模型
type PostActionModel struct {
	conn  *gorm.DB
	redis *redis.Client
}

func NewPostActionModel(conn *gorm.DB, rConn *redis.Client) *PostActionModel {
	return &PostActionModel{
		conn:  conn,
		redis: rConn,
	}
}

func (p *PostActionModel) CreatePostAction(c context.Context, data *PostAction) error {
	return p.conn.WithContext(c).Create(data).Error
}

func (p *PostActionModel) DeletePostAction(c context.Context, data *PostAction) error {
	return p.conn.WithContext(c).Updates(data).Error
}

// CheckPostAction 检查用户是否对帖子执行过某个动作
func (p *PostActionModel) CheckPostAction(ctx context.Context, userId, postId int64, actionType int8) (bool, error) {
	var count int64
	err := p.conn.WithContext(ctx).Model(&PostAction{}).
		Where("user_id = ? AND post_id = ? AND action_type = ? AND is_del = 0", userId, postId, actionType).
		Count(&count).Error
	if err != nil {
		return false, err
	}
	return count > 0, nil
}

const (
	prefixUserCollectionKey = "user:collection:%d:%d:%d" // userId:page:pageSize
)

// GetUserCollectionPosts 获取用户收藏的帖子列表（带缓存）
func (p *PostActionModel) GetUserCollectionPosts(ctx context.Context, userId int64, page, pageSize int) ([]*Post, int64, error) {
	// 尝试从缓存获取
	key := fmt.Sprintf(prefixUserCollectionKey, userId, page, pageSize)
	data, err := p.redis.Get(ctx, key).Bytes()
	if err == nil {
		var cacheData struct {
			Posts []*Post
			Total int64
		}
		if err := json.Unmarshal(data, &cacheData); err == nil {
			return cacheData.Posts, cacheData.Total, nil
		}
	}

	// 从数据库获取
	var posts []*Post
	var total int64

	// 获取收藏总数
	err = p.conn.Model(&PostAction{}).
		Where("user_id = ? AND action_type = ? AND is_del = 0", userId, 1). // 1表示收藏动作
		Count(&total).Error
	if err != nil {
		return nil, 0, err
	}

	// 获取收藏的帖子列表
	offset := (page - 1) * pageSize
	err = p.conn.Table("p_post_action pa").
		Select("p.*").
		Joins("LEFT JOIN p_post p ON p.id = pa.post_id").
		Where("pa.user_id = ? AND pa.action_type = ? AND pa.is_del = 0 AND p.is_del = 0", userId, 1).
		Order("pa.created_on DESC").
		Offset(offset).
		Limit(pageSize).
		Find(&posts).Error
	if err != nil {
		return nil, 0, err
	}

	// 写入缓存
	cacheData := struct {
		Posts []*Post
		Total int64
	}{
		Posts: posts,
		Total: total,
	}
	if data, err := json.Marshal(cacheData); err == nil {
		p.redis.Set(ctx, key, data, 5*time.Minute)
	}

	return posts, total, nil
}

// ClearUserCollectionCache 清除用户收藏列表缓存
func (p *PostActionModel) ClearUserCollectionCache(ctx context.Context, userId int64) {
	pattern := fmt.Sprintf(prefixUserCollectionKey[:strings.LastIndex(prefixUserCollectionKey, ":")]+"*", userId)
	keys, err := p.redis.Keys(ctx, pattern).Result()
	if err != nil {
		return
	}
	if len(keys) > 0 {
		p.redis.Del(ctx, keys...)
	}
}