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ai-agent/internal/ai/rag/retrieve.go
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2026-04-09 10:01:23 +08:00
package rag
import (
"context"
"fmt"
"log/slog"
"sort"
"strings"
"time"
"cs-agent/internal/models"
"github.com/mlogclub/simple/sqls"
"cs-agent/internal/ai"
"cs-agent/internal/ai/rag/vectordb"
"cs-agent/internal/pkg/enums"
"cs-agent/internal/repositories"
)
type retrieve struct {
}
var Retrieve = &retrieve{}
func (s *retrieve) Retrieve(ctx context.Context, req RetrieveRequest) ([]RetrieveResult, error) {
results, _, err := s.RetrieveWithTrace(ctx, req)
return results, err
}
type RetrieveTrace struct {
EmbeddingMs int64
VectorSearchMs int64
HydrateMs int64
}
func (s *retrieve) RetrieveWithTrace(ctx context.Context, req RetrieveRequest) ([]RetrieveResult, *RetrieveTrace, error) {
trace := &RetrieveTrace{}
if req.Query == "" {
return nil, trace, nil
}
knowledgeBaseIDs := normalizeKnowledgeBaseIDs(req.KnowledgeBaseIDs)
if len(knowledgeBaseIDs) == 0 {
return nil, trace, nil
}
retrievableKnowledgeBases := s.loadRetrievableKnowledgeBases(knowledgeBaseIDs)
if len(retrievableKnowledgeBases) == 0 {
slog.Info("Skip retrieve for non-enabled knowledge bases",
"knowledge_base_ids", fmt.Sprint(knowledgeBaseIDs))
return nil, trace, nil
}
embeddingStartedAt := time.Now()
embeddingResult, err := ai.Embedding.GenerateEmbedding(ctx, req.Query)
trace.EmbeddingMs = time.Since(embeddingStartedAt).Milliseconds()
if err != nil {
return nil, trace, fmt.Errorf("failed to generate query embedding: %w", err)
}
collectionName := knowledgeCollectionName
provider := vectordb.GetProvider()
if provider == nil {
return nil, trace, fmt.Errorf("vectordb provider not initialized")
}
searchResults := make([]vectordb.SearchResult, 0)
vectorSearchStartedAt := time.Now()
for _, knowledgeBase := range retrievableKnowledgeBases {
topK, scoreThreshold := resolveKnowledgeBaseSearchOptions(req, &knowledgeBase)
kbResults, searchErr := provider.Search(ctx, &vectordb.SearchRequest{
CollectionName: collectionName,
Vector: embeddingResult.Vector,
TopK: topK,
ScoreThreshold: scoreThreshold,
Filter: &vectordb.SearchFilter{
KnowledgeBaseIDs: []int64{knowledgeBase.ID},
},
})
if searchErr != nil {
slog.Error("Failed to search vectors",
"knowledge_base_id", knowledgeBase.ID,
"error", searchErr)
trace.VectorSearchMs = time.Since(vectorSearchStartedAt).Milliseconds()
return nil, trace, fmt.Errorf("failed to search vectors: %w", searchErr)
}
if len(kbResults) == 0 && scoreThreshold > 0 {
s.logEmptySearchDiagnostics(ctx, provider, collectionName, embeddingResult.Vector, topK, scoreThreshold, []int64{knowledgeBase.ID}, req)
}
searchResults = append(searchResults, kbResults...)
}
trace.VectorSearchMs = time.Since(vectorSearchStartedAt).Milliseconds()
if len(searchResults) == 0 {
return nil, trace, nil
}
sort.SliceStable(searchResults, func(i, j int) bool {
if searchResults[i].Score == searchResults[j].Score {
return searchResults[i].ID < searchResults[j].ID
}
return searchResults[i].Score > searchResults[j].Score
})
results := make([]RetrieveResult, 0, len(searchResults))
hydrateStartedAt := time.Now()
vectorIDs := make([]string, 0, len(searchResults))
for _, sr := range searchResults {
if strings.TrimSpace(sr.ID) == "" {
continue
}
vectorIDs = append(vectorIDs, sr.ID)
}
chunks := repositories.KnowledgeChunkRepository.FindByVectorIDs(sqls.DB(), vectorIDs)
chunkByVectorID := make(map[string]*models.KnowledgeChunk, len(chunks))
documentIDs := make([]int64, 0)
faqIDs := make([]int64, 0)
documentSeen := make(map[int64]struct{})
faqSeen := make(map[int64]struct{})
for i := range chunks {
chunk := &chunks[i]
chunkByVectorID[chunk.VectorID] = chunk
if chunk.DocumentID > 0 {
if _, ok := documentSeen[chunk.DocumentID]; !ok {
documentSeen[chunk.DocumentID] = struct{}{}
documentIDs = append(documentIDs, chunk.DocumentID)
}
}
if chunk.FaqID > 0 {
if _, ok := faqSeen[chunk.FaqID]; !ok {
faqSeen[chunk.FaqID] = struct{}{}
faqIDs = append(faqIDs, chunk.FaqID)
}
}
}
documents := repositories.KnowledgeDocumentRepository.FindByIDs(sqls.DB(), documentIDs)
documentByID := make(map[int64]*models.KnowledgeDocument, len(documents))
for i := range documents {
document := &documents[i]
documentByID[document.ID] = document
}
faqs := repositories.KnowledgeFAQRepository.FindByIDs(sqls.DB(), faqIDs)
faqByID := make(map[int64]*models.KnowledgeFAQ, len(faqs))
for i := range faqs {
faq := &faqs[i]
faqByID[faq.ID] = faq
}
for _, sr := range searchResults {
chunk := chunkByVectorID[sr.ID]
if chunk == nil || chunk.Status != enums.StatusOk {
continue
}
documentTitle := ""
faqQuestion := ""
if chunk.DocumentID > 0 {
document := documentByID[chunk.DocumentID]
if document == nil || document.Status != enums.StatusOk {
continue
}
documentTitle = document.Title
}
if chunk.FaqID > 0 {
faq := faqByID[chunk.FaqID]
if faq == nil || faq.Status != enums.StatusOk {
continue
}
faqQuestion = faq.Question
}
results = append(results, RetrieveResult{
KnowledgeBaseID: chunk.KnowledgeBaseID,
ChunkID: chunk.ID,
DocumentID: chunk.DocumentID,
DocumentTitle: documentTitle,
FaqID: chunk.FaqID,
FaqQuestion: faqQuestion,
ChunkNo: chunk.ChunkNo,
Title: chunk.Title,
SectionPath: chunk.SectionPath,
Content: chunk.Content,
Score: sr.Score,
ChunkType: extractChunkType(sr.Payload),
})
}
trace.HydrateMs = time.Since(hydrateStartedAt).Milliseconds()
return results, trace, nil
}
func extractChunkType(payload vectordb.ChunkPayload) string {
if payload.ChunkType != "" {
return payload.ChunkType
}
return string(enums.KnowledgeChunkTypeText)
}
func (s *retrieve) logEmptySearchDiagnostics(ctx context.Context, provider vectordb.Provider, collectionName string, vector []float32, topK int, scoreThreshold float32, knowledgeBaseIDs []int64, req RetrieveRequest) {
rawResults, err := provider.Search(ctx, &vectordb.SearchRequest{
CollectionName: collectionName,
Vector: vector,
TopK: topK,
ScoreThreshold: 0,
Filter: &vectordb.SearchFilter{
KnowledgeBaseIDs: knowledgeBaseIDs,
},
})
if err != nil {
slog.Warn("Knowledge retrieve diagnostics failed",
"knowledge_base_ids", fmt.Sprint(knowledgeBaseIDs),
"collection", collectionName,
"query", truncateForLog(req.Query, 80),
"score_threshold", scoreThreshold,
"error", err)
return
}
if len(rawResults) == 0 {
slog.Info("Knowledge retrieve returned no candidates even without threshold",
"knowledge_base_ids", fmt.Sprint(knowledgeBaseIDs),
"collection", collectionName,
"query", truncateForLog(req.Query, 80),
"score_threshold", scoreThreshold)
return
}
candidates := make([]string, 0, len(rawResults))
for _, item := range rawResults {
candidates = append(candidates, fmt.Sprintf("%s:%.4f", item.ID, item.Score))
}
slog.Info("Knowledge retrieve filtered all candidates by score threshold",
"knowledge_base_ids", fmt.Sprint(knowledgeBaseIDs),
"collection", collectionName,
"query", truncateForLog(req.Query, 80),
"score_threshold", scoreThreshold,
"top_candidates", strings.Join(candidates, ","))
}
func truncateForLog(text string, limit int) string {
if limit <= 0 {
return ""
}
runes := []rune(strings.TrimSpace(text))
if len(runes) <= limit {
return string(runes)
}
return string(runes[:limit]) + "..."
}
func (s *retrieve) RetrieveWithRerank(ctx context.Context, req RetrieveRequest, rerankLimit int) ([]RetrieveResult, error) {
results, err := s.Retrieve(ctx, req)
if err != nil {
return nil, err
}
if len(results) <= rerankLimit {
return results, nil
}
rerankedResults, err := s.rerank(ctx, req.Query, results, rerankLimit)
if err != nil {
slog.Warn("Rerank failed, returning original results", "error", err)
if len(results) > rerankLimit {
return results[:rerankLimit], nil
}
return results, nil
}
return rerankedResults, nil
}
func (s *retrieve) rerank(ctx context.Context, query string, results []RetrieveResult, limit int) ([]RetrieveResult, error) {
return Rerank.RerankResults(ctx, query, results, limit)
}
func (s *retrieve) SelectContextResults(results []RetrieveResult, maxTokens int) []RetrieveResult {
if len(results) == 0 {
return nil
}
normalizedResults := normalizeContextResults(results)
selected := make([]RetrieveResult, 0, len(normalizedResults))
totalTokens := 0
documentUsage := make(map[int64]int)
for _, item := range normalizedResults {
if documentUsage[item.DocumentID] >= 2 {
continue
}
chunkText := buildContextChunkText(item)
estimatedTokens := len(chunkText) / 2
if totalTokens+estimatedTokens > maxTokens {
break
}
selected = append(selected, item)
totalTokens += estimatedTokens
documentUsage[item.DocumentID]++
}
return selected
}
func (s *retrieve) BuildContext(ctx context.Context, results []RetrieveResult, maxTokens int) string {
if len(results) == 0 {
return ""
}
normalizedResults := s.SelectContextResults(results, maxTokens)
context := ""
for _, r := range normalizedResults {
chunkText := buildContextChunkText(r)
context += chunkText
}
return context
}
func normalizeContextResults(results []RetrieveResult) []RetrieveResult {
if len(results) == 0 {
return nil
}
merged := mergeAdjacentResults(results)
return dedupeSectionResults(merged)
}
func dedupeSectionResults(results []RetrieveResult) []RetrieveResult {
seen := make(map[string]struct{})
deduped := make([]RetrieveResult, 0, len(results))
for _, item := range results {
key := buildSectionKey(item)
if _, ok := seen[key]; ok {
continue
}
seen[key] = struct{}{}
deduped = append(deduped, item)
}
return deduped
}
func mergeAdjacentResults(results []RetrieveResult) []RetrieveResult {
if len(results) == 0 {
return nil
}
merged := make([]RetrieveResult, 0, len(results))
for _, item := range results {
if len(merged) == 0 {
merged = append(merged, item)
continue
}
last := &merged[len(merged)-1]
if canMergeContextResult(*last, item) {
last.Content = strings.TrimSpace(last.Content + "\n" + item.Content)
if item.Score > last.Score {
last.Score = item.Score
}
continue
}
merged = append(merged, item)
}
return merged
}
func canMergeContextResult(left, right RetrieveResult) bool {
if left.FaqID > 0 || right.FaqID > 0 {
return false
}
if left.DocumentID != right.DocumentID {
return false
}
if left.SectionPath == "" || right.SectionPath == "" {
return false
}
if left.SectionPath != right.SectionPath {
return false
}
return right.ChunkNo == left.ChunkNo+1
}
func buildSectionKey(item RetrieveResult) string {
if item.FaqID > 0 {
return fmt.Sprintf("faq:%d", item.FaqID)
}
sectionPath := strings.TrimSpace(item.SectionPath)
if sectionPath != "" {
return fmt.Sprintf("%d|%s", item.DocumentID, sectionPath)
}
title := strings.TrimSpace(item.Title)
if title != "" {
return fmt.Sprintf("%d|%s", item.DocumentID, title)
}
return fmt.Sprintf("%d|chunk:%d", item.DocumentID, item.ChunkNo)
}
func buildContextChunkText(item RetrieveResult) string {
if item.FaqID > 0 {
title := strings.TrimSpace(item.FaqQuestion)
if title == "" {
title = strings.TrimSpace(item.Title)
}
if title == "" {
title = fmt.Sprintf("FAQ#%d", item.FaqID)
}
return fmt.Sprintf("【FAQ%s】\n%s\n\n", title, item.Content)
}
title := strings.TrimSpace(item.DocumentTitle)
if title == "" {
title = fmt.Sprintf("文档#%d", item.DocumentID)
}
if item.SectionPath != "" {
return fmt.Sprintf("【文档:%s|章节:%s】\n%s\n\n", title, item.SectionPath, item.Content)
}
if item.Title != "" {
return fmt.Sprintf("【文档:%s|标题:%s】\n%s\n\n", title, item.Title, item.Content)
}
return fmt.Sprintf("【文档:%s】\n%s\n\n", title, item.Content)
}
func (s *retrieve) GetKnowledgeBaseStats(ctx context.Context, knowledgeBaseID int64) (*KnowledgeBaseStats, error) {
knowledgeBase := repositories.KnowledgeBaseRepository.Get(sqls.DB(), knowledgeBaseID)
if knowledgeBase == nil {
return nil, fmt.Errorf("knowledge base not found")
}
documentCount := repositories.KnowledgeDocumentRepository.CountByKnowledgeBaseID(sqls.DB(), knowledgeBaseID)
chunkCount := repositories.KnowledgeChunkRepository.CountByKnowledgeBaseID(sqls.DB(), knowledgeBaseID)
publishedCount := repositories.KnowledgeDocumentRepository.Count(sqls.DB(), sqls.NewCnd().
Eq("knowledge_base_id", knowledgeBaseID).
Eq("status", enums.StatusOk))
return &KnowledgeBaseStats{
KnowledgeBaseID: knowledgeBaseID,
DocumentCount: documentCount,
PublishedCount: publishedCount,
ChunkCount: chunkCount,
VectorCount: int(chunkCount),
}, nil
}
func normalizeKnowledgeBaseIDs(ids []int64) []int64 {
if len(ids) == 0 {
return nil
}
seen := make(map[int64]struct{}, len(ids))
normalized := make([]int64, 0, len(ids))
for _, id := range ids {
if id <= 0 {
continue
}
if _, ok := seen[id]; ok {
continue
}
seen[id] = struct{}{}
normalized = append(normalized, id)
}
return normalized
}
func resolveKnowledgeBaseSearchOptions(req RetrieveRequest, knowledgeBase *models.KnowledgeBase) (int, float32) {
topK := req.TopK
if topK <= 0 && knowledgeBase != nil && knowledgeBase.DefaultTopK > 0 {
topK = knowledgeBase.DefaultTopK
}
if topK <= 0 {
topK = 8
}
scoreThreshold := float32(req.ScoreThreshold)
if scoreThreshold <= 0 && knowledgeBase != nil && knowledgeBase.DefaultScoreThreshold > 0 {
scoreThreshold = float32(knowledgeBase.DefaultScoreThreshold)
}
if scoreThreshold <= 0 {
scoreThreshold = 0.3
}
return topK, scoreThreshold
}
func (s *retrieve) loadRetrievableKnowledgeBases(ids []int64) []models.KnowledgeBase {
if len(ids) == 0 {
return nil
}
items := repositories.KnowledgeBaseRepository.Find(sqls.DB(), sqls.NewCnd().In("id", ids))
if len(items) == 0 {
return nil
}
allowed := make(map[int64]models.KnowledgeBase, len(items))
for _, item := range items {
if item.Status == enums.StatusOk {
allowed[item.ID] = item
}
}
filtered := make([]models.KnowledgeBase, 0, len(ids))
for _, id := range ids {
if item, ok := allowed[id]; ok {
filtered = append(filtered, item)
}
}
return filtered
}
type KnowledgeBaseStats struct {
KnowledgeBaseID int64 `json:"knowledgeBaseId"`
DocumentCount int64 `json:"documentCount"`
PublishedCount int64 `json:"publishedCount"`
ChunkCount int64 `json:"chunkCount"`
VectorCount int `json:"vectorCount"`
}