package memory

import (
	"fmt"

	"github.com/hxclaw/hxclaw/cmd/hxclaw/internal"
)

type RecallResult struct {
	Type      string    `json:"type"`
	Message   string    `json:"message"`
	Sessions  []*Session `json:"sessions,omitempty"`
	Chats     []*Chat    `json:"chats,omitempty"`
}

func RecallHistory() (*RecallResult, error) {
	db := GetDB()
	if db == nil {
		return nil, fmt.Errorf("数据库未初始化")
	}

	sessions, err := db.GetAllSessions()
	if err != nil {
		return nil, fmt.Errorf("查询会话失败: %v", err)
	}

	if len(sessions) == 0 {
		return &RecallResult{
			Type:    "history",
			Message: "暂无历史会话记录",
		}, nil
	}

	msg := "以下是所有历史会话摘要：\n\n"
	for i, s := range sessions {
		summary := s.Summary
		if summary == "" {
			summary = "（暂无摘要）"
		}
		msg += fmt.Sprintf("**会话 %d** (ID: %d)\n%s\n\n", i+1, s.ID, summary)
	}

	return &RecallResult{
		Type:      "history",
		Message:   msg,
		Sessions:  sessions,
	}, nil
}

func RecallTopic(query string, topK int) (*RecallResult, error) {
	vs := GetVectorService()
	if vs == nil {
		return nil, fmt.Errorf("向量服务未初始化")
	}

	cfg := internal.GetProjectConfig().Memory
	if topK <= 0 {
		topK = cfg.Vector.MaxSearchResults
		if topK <= 0 {
			topK = 5
		}
	}

	results, err := SearchSimilar(query, topK)
	if err != nil {
		return nil, fmt.Errorf("向量检索失败: %v", err)
	}

	if len(results) == 0 {
		return &RecallResult{
			Type:    "topic",
			Message: fmt.Sprintf("未找到与「%s」相关的内容", query),
		}, nil
	}

	type sessionChat struct {
		sessionID int64
		chat      *Chat
		similarity float64
	}

	sessionChats := make(map[int64]*sessionChat)
	for _, r := range results {
		if existing, ok := sessionChats[r.Chat.SessionID]; ok {
			if r.Similarity > existing.similarity {
				sessionChats[r.Chat.SessionID] = &sessionChat{
					sessionID: r.Chat.SessionID,
					chat:      r.Chat,
					similarity: r.Similarity,
				}
			}
		} else {
			sessionChats[r.Chat.SessionID] = &sessionChat{
				sessionID: r.Chat.SessionID,
				chat:      r.Chat,
				similarity: r.Similarity,
			}
		}
	}

	msg := fmt.Sprintf("找到与「%s」相关的内容：\n\n", query)
	var chats []*Chat
	for _, sc := range sessionChats {
		msg += fmt.Sprintf("**会话 %d** (相似度: %.2f)\n%s\n\n",
			sc.sessionID, sc.similarity, sc.chat.Summary)
		chats = append(chats, sc.chat)
	}

	return &RecallResult{
		Type:    "topic",
		Message: msg,
		Chats:   chats,
	}, nil
}

func RecallSession(sessionID int64) (*RecallResult, error) {
	db := GetDB()
	if db == nil {
		return nil, fmt.Errorf("数据库未初始化")
	}

	session, err := db.GetSessionByID(sessionID)
	if err != nil {
		return nil, fmt.Errorf("查询会话失败: %v", err)
	}
	if session == nil {
		return &RecallResult{
			Type:    "session",
			Message: fmt.Sprintf("未找到会话 ID: %d", sessionID),
		}, nil
	}

	msg := fmt.Sprintf("**会话 %d 的摘要**\n\n%s", sessionID, session.Summary)

	return &RecallResult{
		Type:     "session",
		Message:  msg,
		Sessions: []*Session{session},
	}, nil
}

func RecallWithinSession(sessionID int64, query string) (*RecallResult, error) {
	db := GetDB()
	if db == nil {
		return nil, fmt.Errorf("数据库未初始化")
	}

	chats, err := db.GetChatsBySessionID(sessionID)
	if err != nil {
		return nil, fmt.Errorf("查询聊天记录失败: %v", err)
	}

	if len(chats) == 0 {
		return &RecallResult{
			Type:    "within_session",
			Message: fmt.Sprintf("会话 %d 中暂无聊天记录", sessionID),
		}, nil
	}

	vs := GetVectorService()
	if vs == nil {
		return nil, fmt.Errorf("向量服务未初始化")
	}

	queryEmb, err := vs.Generate(query)
	if err != nil {
		return nil, fmt.Errorf("生成查询向量失败: %v", err)
	}

	type scoredChat struct {
		chat      *Chat
		similarity float64
	}

	var scored []scoredChat
	for _, c := range chats {
		if len(c.SummaryEmbedding) == 0 {
			continue
		}
		sim := vs.CosineSimilarity(queryEmb, c.SummaryEmbedding)
		scored = append(scored, scoredChat{chat: c, similarity: sim})
	}

	for i := 0; i < len(scored); i++ {
		for j := i + 1; j < len(scored); j++ {
			if scored[j].similarity > scored[i].similarity {
				scored[i], scored[j] = scored[j], scored[i]
			}
		}
	}

	topK := 3
	if topK > len(scored) {
		topK = len(scored)
	}

	msg := fmt.Sprintf("会话 %d 中与「%s」相关内容：\n\n", sessionID, query)
	var matchedChats []*Chat
	for i := 0; i < topK; i++ {
		msg += fmt.Sprintf("**相似度: %.2f**\n%s\n\n",
			scored[i].similarity, scored[i].chat.Summary)
		matchedChats = append(matchedChats, scored[i].chat)
	}

	return &RecallResult{
		Type:    "within_session",
		Message: msg,
		Chats:   matchedChats,
	}, nil
}

func FormatRecallResults(result *RecallResult) string {
	return result.Message
}