fix(openai): keep citation indexes one-based

internal/httpapi/openai/citation_links_test.go

@@ -54,3 +54,31 @@ func TestReplaceCitationMarkersWithLinksSupportsReferenceZeroBased(t *testing.T)
 		t.Fatalf("expected %q, got %q", want, got)
 	}
 }
+
+func TestReplaceCitationMarkersWithLinksKeepsCitationOneBasedWithZeroBasedReference(t *testing.T) {
+	raw := "引用[citation:1]，来源[reference:0]，后续[reference:1]。"
+	links := map[int]string{
+		1: "https://example.com/first",
+		2: "https://example.com/second",
+	}
+
+	got := replaceCitationMarkersWithLinks(raw, links)
+	want := "引用[1](https://example.com/first)，来源[0](https://example.com/first)，后续[1](https://example.com/second)。"
+	if got != want {
+		t.Fatalf("expected %q, got %q", want, got)
+	}
+}
+
+func TestReplaceCitationMarkersWithLinksDetectsSpacedReferenceZeroBased(t *testing.T) {
+	raw := "来源[reference: 0] 与 [reference: 1]。"
+	links := map[int]string{
+		1: "https://example.com/first",
+		2: "https://example.com/second",
+	}
+
+	got := replaceCitationMarkersWithLinks(raw, links)
+	want := "来源[0](https://example.com/first) 与 [1](https://example.com/second)。"
+	if got != want {
+		t.Fatalf("expected %q, got %q", want, got)
+	}
+}

internal/httpapi/openai/shared/citation_links.go

@@ -13,7 +13,7 @@ func ReplaceCitationMarkersWithLinks(text string, links map[int]string) string {
 	if strings.TrimSpace(text) == "" || len(links) == 0 {
 		return text
 	}
-	zeroBased := strings.Contains(strings.ToLower(text), "[reference:0]")
+	zeroBasedReference := hasZeroBasedReferenceMarker(text)
 	return citationMarkerPattern.ReplaceAllStringFunc(text, func(match string) string {
 		sub := citationMarkerPattern.FindStringSubmatch(match)
 		if len(sub) < 3 {
@@ -24,7 +24,7 @@ func ReplaceCitationMarkersWithLinks(text string, links map[int]string) string {
 			return match
 		}
 		lookupIdx := idx
-		if zeroBased {
+		if strings.EqualFold(sub[1], "reference") && zeroBasedReference {
 			lookupIdx = idx + 1
 		}
 		url := strings.TrimSpace(links[lookupIdx])
@@ -34,3 +34,16 @@ func ReplaceCitationMarkersWithLinks(text string, links map[int]string) string {
 		return fmt.Sprintf("[%d](%s)", idx, url)
 	})
 }
+
+func hasZeroBasedReferenceMarker(text string) bool {
+	for _, sub := range citationMarkerPattern.FindAllStringSubmatch(text, -1) {
+		if len(sub) < 3 || !strings.EqualFold(sub[1], "reference") {
+			continue
+		}
+		idx, err := strconv.Atoi(strings.TrimSpace(sub[2]))
+		if err == nil && idx == 0 {
+			return true
+		}
+	}
+	return false
+}