feat: harden search ranking and deduplication

internal/isphere/groups.go

@@ -38,24 +38,32 @@ func SearchGroupsFromMessages(messages []Message, query SearchGroupsQuery) Searc
 		}
 	}
 
-	queryText := strings.ToLower(strings.TrimSpace(query.Query))
-	ids := make([]string, 0, len(unique))
-	for id := range unique {
-		if queryText == "" || strings.Contains(strings.ToLower(id), queryText) || strings.Contains(strings.ToLower(unique[id].DisplayName), queryText) {
-			ids = append(ids, id)
+	queryText := normalizedSearchText(query.Query)
+	groups := make([]Group, 0, len(unique))
+	for _, group := range unique {
+		if groupMatchesQuery(group, queryText) {
+			groups = append(groups, group)
 		}
 	}
-	sort.Strings(ids)
+	sort.Slice(groups, func(i, j int) bool {
+		leftRank := groupSearchRank(groups[i], queryText)
+		rightRank := groupSearchRank(groups[j], queryText)
+		if leftRank != rightRank {
+			return leftRank < rightRank
+		}
+		leftID := strings.ToLower(groups[i].GroupID)
+		rightID := strings.ToLower(groups[j].GroupID)
+		if leftID != rightID {
+			return leftID < rightID
+		}
+		return groups[i].GroupID < groups[j].GroupID
+	})
 
 	limit := query.Limit
-	if limit <= 0 || limit > len(ids) {
-		limit = len(ids)
+	if limit <= 0 || limit > len(groups) {
+		limit = len(groups)
 	}
-	groups := make([]Group, 0, limit)
-	for _, id := range ids[:limit] {
-		groups = append(groups, unique[id])
-	}
-	return SearchGroupsResult{Groups: groups}
+	return SearchGroupsResult{Groups: groups[:limit]}
 }
 
 func addMessageGroup(unique map[string]Group, id string) {
@@ -63,10 +71,11 @@ func addMessageGroup(unique map[string]Group, id string) {
 	if trimmed == "" || !isLikelyGroupJID(trimmed) {
 		return
 	}
-	if _, exists := unique[trimmed]; exists {
+	key := strings.ToLower(trimmed)
+	if _, exists := unique[key]; exists {
 		return
 	}
-	unique[trimmed] = Group{
+	unique[key] = Group{
 		GroupID:     trimmed,
 		DisplayName: trimmed,
 		Source:      "local_readonly",
@@ -79,3 +88,32 @@ func isLikelyGroupJID(id string) bool {
 	lower := strings.ToLower(strings.TrimSpace(id))
 	return strings.Contains(lower, "conference") || strings.Contains(lower, "muc") || strings.Contains(lower, "group")
 }
+
+func groupMatchesQuery(group Group, queryText string) bool {
+	if queryText == "" {
+		return true
+	}
+	return strings.Contains(strings.ToLower(group.GroupID), queryText) ||
+		strings.Contains(strings.ToLower(group.DisplayName), queryText)
+}
+
+func groupSearchRank(group Group, queryText string) int {
+	if queryText == "" {
+		return 0
+	}
+	values := []string{
+		strings.ToLower(group.GroupID),
+		strings.ToLower(group.DisplayName),
+	}
+	for _, value := range values {
+		if value == queryText {
+			return 0
+		}
+	}
+	for _, value := range values {
+		if strings.HasPrefix(value, queryText) {
+			return 1
+		}
+	}
+	return 2
+}