anthropic: improve handling of multipart tool responses

llms/anthropic/anthropicllm.go

@@ -272,35 +272,52 @@
 	return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for human message", ErrInvalidContentType)
 }
 
-func handleAIMessage(msg llms.MessageContent) (anthropicclient.ChatMessage, error) {
-	if toolCall, ok := msg.Parts[0].(llms.ToolCall); ok {
-		var inputStruct map[string]interface{}
-		err := json.Unmarshal([]byte(toolCall.FunctionCall.Arguments), &inputStruct)
-		if err != nil {
-			return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: failed to unmarshal tool call arguments: %w", err)
-		}
-		toolUse := anthropicclient.ToolUseContent{
-			Type:  "tool_use",
-			ID:    toolCall.ID,
-			Name:  toolCall.FunctionCall.Name,
-			Input: inputStruct,
-		}
+func getTextPart(part llms.TextContent) *anthropicclient.TextContent {
+	return &anthropicclient.TextContent{
+		Type: "text",
+		Text: part.Text,
+	}
+}
 
-		return anthropicclient.ChatMessage{
-			Role:    RoleAssistant,
-			Content: []anthropicclient.Content{toolUse},
-		}, nil
+func getToolPart(part llms.ToolCall) (*anthropicclient.ToolUseContent, error) {
+	var inputStruct map[string]interface{}
+	err := json.Unmarshal([]byte(part.FunctionCall.Arguments), &inputStruct)
+	if err != nil {
+		return nil, fmt.Errorf("anthropic: failed to unmarshal tool call arguments: %w", err)
 	}
-	if textContent, ok := msg.Parts[0].(llms.TextContent); ok {
-		return anthropicclient.ChatMessage{
-			Role: RoleAssistant,
-			Content: []anthropicclient.Content{&anthropicclient.TextContent{
-				Type: "text",
-				Text: textContent.Text,
-			}},
-		}, nil
+	return &anthropicclient.ToolUseContent{
+		Type:  "tool_use",
+		ID:    part.ID,
+		Name:  part.FunctionCall.Name,
+		Input: inputStruct,
+	}, nil
+}
+
+func handleAIMessage(msg llms.MessageContent) (anthropicclient.ChatMessage, error) {
+	cm := anthropicclient.ChatMessage{
+		Role:    RoleAssistant,
+		Content: make([]anthropicclient.Content, 0),
 	}
-	return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for AI message", ErrInvalidContentType)
+
+	contentArr := make([]anthropicclient.Content, 0)
+
+	for _, part := range msg.Parts {
+		switch part.(type) {
+		case llms.TextContent:
+			contentArr = append(contentArr, getTextPart(part.(llms.TextContent)))
+		case llms.ToolCall:
+			tp, err := getToolPart(part.(llms.ToolCall))
+			if err != nil {
+				return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for AI message %T", err, part)
+			}
+			contentArr = append(contentArr, tp)
+		default:
+			return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for AI message %T", ErrInvalidContentType, part)
+		}
+	}
+
+	cm.Content = contentArr
+	return cm, nil
 }
 
 type ToolResult struct {
@@ -309,18 +326,39 @@
 	Content   string `json:"content"`
 }
 
+func getToolResponse(part llms.ToolCallResponse) (*anthropicclient.ToolResultContent, error) {
+	return &anthropicclient.ToolResultContent{
+		Type:      "tool_result",
+		ToolUseID: part.ToolCallID,
+		Content:   part.Content,
+	}, nil
+
+}
+
 func handleToolMessage(msg llms.MessageContent) (anthropicclient.ChatMessage, error) {
-	if toolCallResponse, ok := msg.Parts[0].(llms.ToolCallResponse); ok {
-		toolContent := anthropicclient.ToolResultContent{
-			Type:      "tool_result",
-			ToolUseID: toolCallResponse.ToolCallID,
-			Content:   toolCallResponse.Content,
-		}
+	cm := anthropicclient.ChatMessage{
+		Role:    RoleUser,
+		Content: make([]anthropicclient.Content, 0),
+	}
 
-		return anthropicclient.ChatMessage{
-			Role:    RoleUser,
-			Content: []anthropicclient.Content{toolContent},
-		}, nil
+	contentArr := make([]anthropicclient.Content, 0)
+
+	for _, part := range msg.Parts {
+		switch part.(type) {
+		case llms.TextContent:
+			contentArr = append(contentArr, getTextPart(part.(llms.TextContent)))
+		case llms.ToolCallResponse:
+			tp, err := getToolResponse(part.(llms.ToolCallResponse))
+			if err != nil {
+				return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for tool part response message %T", err, part)
+			}
+			contentArr = append(contentArr, tp)
+		default:
+			return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for AI message %T", ErrInvalidContentType, part)
+		}
 	}
-	return anthropicclient.ChatMessage{}, fmt.Errorf("anthropic: %w for tool message", ErrInvalidContentType)
+
+	cm.Content = contentArr
+
+	return cm, nil
 }