v0.3.8

internal/backend/agent/model/content_parts.go

@@ -0,0 +1,213 @@
+package modeladapter
+
+import (
+	"encoding/base64"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	contentPartTypeText  = "text"
+	contentPartTypeImage = "image"
+)
+
+// ContentPart 表示一条消息中的结构化内容块。
+type ContentPart struct {
+	Type  string        `json:"type"`
+	Text  string        `json:"text,omitempty"`
+	Image *ImageContent `json:"image,omitempty"`
+}
+
+// ImageContent 表示消息中携带的一张图片。
+type ImageContent struct {
+	MIMEType string `json:"mime_type,omitempty"`
+	Path     string `json:"path,omitempty"`
+	Data     []byte `json:"data,omitempty"`
+}
+
+func hasImageContentParts(parts []ContentPart) bool {
+	for _, part := range parts {
+		if normalizeContentPartType(part.Type) == contentPartTypeImage {
+			return true
+		}
+	}
+	return false
+}
+
+func collapseTextContentParts(parts []ContentPart) string {
+	if len(parts) == 0 {
+		return ""
+	}
+	texts := make([]string, 0, len(parts))
+	for _, part := range parts {
+		if normalizeContentPartType(part.Type) != contentPartTypeText {
+			continue
+		}
+		if strings.TrimSpace(part.Text) == "" {
+			continue
+		}
+		texts = append(texts, part.Text)
+	}
+	return strings.Join(texts, "")
+}
+
+func normalizeContentPartType(value string) string {
+	trimmed := strings.TrimSpace(strings.ToLower(value))
+	switch trimmed {
+	case "", contentPartTypeText:
+		return contentPartTypeText
+	case contentPartTypeImage:
+		return contentPartTypeImage
+	default:
+		return trimmed
+	}
+}
+
+func openAIContentValue(message Message) (any, error) {
+	if !hasImageContentParts(message.ContentParts) {
+		content := message.Content
+		if strings.TrimSpace(content) == "" && len(message.ContentParts) > 0 {
+			content = collapseTextContentParts(message.ContentParts)
+		}
+		return content, nil
+	}
+
+	parts := make([]map[string]any, 0, len(message.ContentParts)+1)
+	if len(message.ContentParts) == 0 && strings.TrimSpace(message.Content) != "" {
+		parts = append(parts, map[string]any{
+			"type": contentPartTypeText,
+			"text": message.Content,
+		})
+	}
+	for _, part := range message.ContentParts {
+		switch normalizeContentPartType(part.Type) {
+		case contentPartTypeText:
+			if part.Text == "" {
+				continue
+			}
+			parts = append(parts, map[string]any{
+				"type": contentPartTypeText,
+				"text": part.Text,
+			})
+		case contentPartTypeImage:
+			dataURL, err := imageContentDataURL(part.Image)
+			if err != nil {
+				return nil, err
+			}
+			parts = append(parts, map[string]any{
+				"type": "image_url",
+				"image_url": map[string]any{
+					"url": dataURL,
+				},
+			})
+		default:
+			return nil, fmt.Errorf("unsupported openai content part type: %s", strings.TrimSpace(part.Type))
+		}
+	}
+	if len(parts) == 0 {
+		return message.Content, nil
+	}
+	return parts, nil
+}
+
+func anthropicContentBlocks(message Message) ([]map[string]any, error) {
+	if len(message.ContentParts) == 0 {
+		if strings.TrimSpace(message.Content) == "" {
+			return nil, nil
+		}
+		return []map[string]any{{
+			"type": contentPartTypeText,
+			"text": message.Content,
+		}}, nil
+	}
+
+	blocks := make([]map[string]any, 0, len(message.ContentParts))
+	for _, part := range message.ContentParts {
+		switch normalizeContentPartType(part.Type) {
+		case contentPartTypeText:
+			if part.Text == "" {
+				continue
+			}
+			blocks = append(blocks, map[string]any{
+				"type": contentPartTypeText,
+				"text": part.Text,
+			})
+		case contentPartTypeImage:
+			payload, mediaType, err := resolveImageContent(part.Image)
+			if err != nil {
+				return nil, err
+			}
+			blocks = append(blocks, map[string]any{
+				"type": contentPartTypeImage,
+				"source": map[string]any{
+					"type":       "base64",
+					"media_type": mediaType,
+					"data":       base64.StdEncoding.EncodeToString(payload),
+				},
+			})
+		default:
+			return nil, fmt.Errorf("unsupported anthropic content part type: %s", strings.TrimSpace(part.Type))
+		}
+	}
+	if len(blocks) == 0 && strings.TrimSpace(message.Content) != "" {
+		blocks = append(blocks, map[string]any{
+			"type": contentPartTypeText,
+			"text": message.Content,
+		})
+	}
+	return blocks, nil
+}
+
+func imageContentDataURL(image *ImageContent) (string, error) {
+	payload, mediaType, err := resolveImageContent(image)
+	if err != nil {
+		return "", err
+	}
+	return "data:" + mediaType + ";base64," + base64.StdEncoding.EncodeToString(payload), nil
+}
+
+func resolveImageContent(image *ImageContent) ([]byte, string, error) {
+	if image == nil {
+		return nil, "", fmt.Errorf("image content is required")
+	}
+	if len(image.Data) > 0 {
+		return image.Data, normalizeImageMIMEType(image.MIMEType, image.Path, image.Data), nil
+	}
+	path := strings.TrimSpace(image.Path)
+	if path == "" {
+		return nil, "", fmt.Errorf("image content is missing data and path")
+	}
+	payload, err := os.ReadFile(path)
+	if err != nil {
+		return nil, "", fmt.Errorf("read image content failed: %w", err)
+	}
+	return payload, normalizeImageMIMEType(image.MIMEType, path, payload), nil
+}
+
+func normalizeImageMIMEType(mimeType string, path string, payload []byte) string {
+	trimmed := strings.TrimSpace(strings.ToLower(mimeType))
+	if trimmed != "" {
+		return trimmed
+	}
+	if len(payload) > 0 {
+		detected := strings.TrimSpace(strings.ToLower(http.DetectContentType(payload)))
+		if strings.HasPrefix(detected, "image/") {
+			return detected
+		}
+	}
+	switch strings.ToLower(filepath.Ext(strings.TrimSpace(path))) {
+	case ".jpg", ".jpeg":
+		return "image/jpeg"
+	case ".png":
+		return "image/png"
+	case ".gif":
+		return "image/gif"
+	case ".webp":
+		return "image/webp"
+	default:
+		return "image/png"
+	}
+}