backend/internal/cache/keys.go

package cache

import (
	"fmt"
)

// 缓存键前缀常量
const (
	// 帖子相关
	PrefixPostList = "posts:list"
	PrefixPost     = "posts:detail"

	// 会话相关
	PrefixConversationList   = "conversations:list"
	PrefixConversationDetail = "conversations:detail"

	// 群组相关
	PrefixGroupMembers = "groups:members"
	PrefixGroupInfo    = "groups:info"

	// 未读数相关
	PrefixUnreadSystem       = "unread:system"
	PrefixUnreadConversation = "unread:conversation"
	PrefixUnreadDetail       = "unread:detail"

	// 用户相关
	PrefixUserInfo = "users:info"
	PrefixUserMe   = "users:me"

	// 消息缓存相关
	keyPrefixMsgHash  = "msg_hash"  // 消息详情 Hash
	keyPrefixMsgIndex = "msg_index" // 消息索引 Sorted Set
	keyPrefixMsgCount = "msg_count" // 消息计数
	keyPrefixMsgSeq   = "msg_seq"   // Seq 计数器
	keyPrefixMsgPage  = "msg_page"  // 分页缓存
)

// PostListKey 生成帖子列表缓存键
// postType: 帖子类型 (recommend, hot, follow, latest)
// page: 页码
// pageSize: 每页数量
// userID: 用户维度（仅在个性化列表如 follow 场景使用）
func PostListKey(postType string, userID string, page, pageSize int) string {
	if userID == "" {
		return fmt.Sprintf("%s:%s:%d:%d", PrefixPostList, postType, page, pageSize)
	}
	return fmt.Sprintf("%s:%s:%s:%d:%d", PrefixPostList, postType, userID, page, pageSize)
}

// PostDetailKey 生成帖子详情缓存键
func PostDetailKey(postID string) string {
	return fmt.Sprintf("%s:%s", PrefixPost, postID)
}

// ConversationListKey 生成会话列表缓存键
func ConversationListKey(userID string, page, pageSize int) string {
	return fmt.Sprintf("%s:%s:%d:%d", PrefixConversationList, userID, page, pageSize)
}

// ConversationDetailKey 生成会话详情缓存键
func ConversationDetailKey(conversationID, userID string) string {
	return fmt.Sprintf("%s:%s:%s", PrefixConversationDetail, conversationID, userID)
}

// GroupMembersKey 生成群组成员缓存键
func GroupMembersKey(groupID string, page, pageSize int) string {
	return fmt.Sprintf("%s:%s:page:%d:size:%d", PrefixGroupMembers, groupID, page, pageSize)
}

// GroupMembersAllKey 生成群组全量成员ID列表缓存键
func GroupMembersAllKey(groupID string) string {
	return fmt.Sprintf("%s:all:%s", PrefixGroupMembers, groupID)
}

// GroupInfoKey 生成群组信息缓存键
func GroupInfoKey(groupID string) string {
	return fmt.Sprintf("%s:%s", PrefixGroupInfo, groupID)
}

// UnreadSystemKey 生成系统消息未读数缓存键
func UnreadSystemKey(userID string) string {
	return fmt.Sprintf("%s:%s", PrefixUnreadSystem, userID)
}

// UnreadConversationKey 生成会话未读总数缓存键
func UnreadConversationKey(userID string) string {
	return fmt.Sprintf("%s:%s", PrefixUnreadConversation, userID)
}

// UnreadDetailKey 生成单个会话未读数缓存键
func UnreadDetailKey(userID, conversationID string) string {
	return fmt.Sprintf("%s:%s:%s", PrefixUnreadDetail, userID, conversationID)
}

// UserInfoKey 生成用户信息缓存键
func UserInfoKey(userID string) string {
	return fmt.Sprintf("%s:%s", PrefixUserInfo, userID)
}

// UserMeKey 生成当前用户信息缓存键
func UserMeKey(userID string) string {
	return fmt.Sprintf("%s:%s", PrefixUserMe, userID)
}

// InvalidatePostList 失效帖子列表缓存
func InvalidatePostList(cache Cache) {
	cache.DeleteByPrefix(PrefixPostList)
}

// InvalidatePostDetail 失效帖子详情缓存
func InvalidatePostDetail(cache Cache, postID string) {
	cache.Delete(PostDetailKey(postID))
}

// InvalidateConversationList 失效会话列表缓存
func InvalidateConversationList(cache Cache, userID string) {
	cache.DeleteByPrefix(PrefixConversationList + ":" + userID + ":")
}

// InvalidateConversationDetail 失效会话详情缓存
func InvalidateConversationDetail(cache Cache, conversationID, userID string) {
	cache.Delete(ConversationDetailKey(conversationID, userID))
}

// InvalidateGroupMembers 失效群组成员缓存
func InvalidateGroupMembers(cache Cache, groupID string) {
	cache.DeleteByPrefix(PrefixGroupMembers + ":" + groupID)
}

// InvalidateGroupInfo 失效群组信息缓存
func InvalidateGroupInfo(cache Cache, groupID string) {
	cache.Delete(GroupInfoKey(groupID))
}

// InvalidateUnreadSystem 失效系统消息未读数缓存
func InvalidateUnreadSystem(cache Cache, userID string) {
	cache.Delete(UnreadSystemKey(userID))
}

// InvalidateUnreadConversation 失效会话未读数缓存
func InvalidateUnreadConversation(cache Cache, userID string) {
	cache.Delete(UnreadConversationKey(userID))
}

// InvalidateUnreadDetail 失效单个会话未读数缓存
func InvalidateUnreadDetail(cache Cache, userID, conversationID string) {
	cache.Delete(UnreadDetailKey(userID, conversationID))
}

// InvalidateUserInfo 失效用户信息缓存
func InvalidateUserInfo(cache Cache, userID string) {
	cache.Delete(UserInfoKey(userID))
	cache.Delete(UserMeKey(userID))
}

// ============================================================
// 消息缓存 Key 生成函数
// ============================================================

// MessageHashKey 消息详情 Hash key
func MessageHashKey(convID string) string {
	return fmt.Sprintf("%s:%s", keyPrefixMsgHash, convID)
}

// MessageIndexKey 消息索引 Sorted Set key
func MessageIndexKey(convID string) string {
	return fmt.Sprintf("%s:%s", keyPrefixMsgIndex, convID)
}

// MessageCountKey 消息计数 key
func MessageCountKey(convID string) string {
	return fmt.Sprintf("%s:%s", keyPrefixMsgCount, convID)
}

// MessageSeqKey Seq 计数器 key
func MessageSeqKey(convID string) string {
	return fmt.Sprintf("%s:%s", keyPrefixMsgSeq, convID)
}

// MessagePageKey 分页缓存 key
func MessagePageKey(convID string, page, pageSize int) string {
	return fmt.Sprintf("%s:%s:%d:%d", keyPrefixMsgPage, convID, page, pageSize)
}

// InvalidateMessagePages 失效会话消息分页缓存
func InvalidateMessagePages(cache Cache, conversationID string) {
	cache.DeleteByPrefix(fmt.Sprintf("%s:%s:", keyPrefixMsgPage, conversationID))
}