feat: Introduce JSON decoding utility functions and update error handling in…

feat: Introduce JSON decoding utility functions and update error handling in Claude and OpenAI response structures

common/json.go

+package common
+
+import (
+	"bytes"
+	"encoding/json"
+)
+
+func DecodeJson(data []byte, v any) error {
+	return json.NewDecoder(bytes.NewReader(data)).Decode(v)
+}
+
+func DecodeJsonStr(data string, v any) error {
+	return DecodeJson(StringToByteSlice(data), v)
+}

dto/claude.go

@@ -165,8 +165,8 @@ func (c *ClaudeRequest) ParseSystem() []ClaudeMediaMessage {
 }
 
 type ClaudeError struct {
-	Type    string `json:"type"`
-	Message string `json:"message"`
+	Type    string `json:"type,omitempty"`
+	Message string `json:"message,omitempty"`
 }
 
 type ClaudeErrorWithStatusCode struct {

dto/openai_response.go

 package dto
 
 type SimpleResponse struct {
-	Usage   `json:"usage"`
-	Error   OpenAIError                `json:"error"`
-	Choices []OpenAITextResponseChoice `json:"choices"`
+	Usage `json:"usage"`
+	Error *OpenAIError `json:"error"`
 }
 
 type TextResponse struct {
@@ -27,6 +26,7 @@ type OpenAITextResponse struct {
 	Object  string                     `json:"object"`
 	Created int64                      `json:"created"`
 	Choices []OpenAITextResponseChoice `json:"choices"`
+	Error   *OpenAIError               `json:"error"`
 	Usage   `json:"usage"`
 }
 

relay/channel/claude/relay-claude.go

 package claude
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -481,7 +480,7 @@ func FormatClaudeResponseInfo(requestMode int, claudeResponse *dto.ClaudeRespons
 
 func HandleResponseData(c *gin.Context, info *relaycommon.RelayInfo, claudeInfo *ClaudeResponseInfo, data string, requestMode int) error {
 	var claudeResponse dto.ClaudeResponse
-	err := json.NewDecoder(bytes.NewReader(common.StringToByteSlice(data))).Decode(&claudeResponse)
+	err := common.DecodeJsonStr(data, &claudeResponse)
 	if err != nil {
 		common.SysError("error unmarshalling stream response: " + err.Error())
 		return fmt.Errorf("error unmarshalling stream aws response: %w", err)

relay/channel/openai/relay-openai.go

@@ -33,7 +33,7 @@ func sendStreamData(c *gin.Context, info *relaycommon.RelayInfo, data string, fo
 	}
 
 	var lastStreamResponse dto.ChatCompletionsStreamResponse
-	if err := json.Unmarshal(common.StringToByteSlice(data), &lastStreamResponse); err != nil {
+	if err := common.DecodeJsonStr(data, &lastStreamResponse); err != nil {
 		return err
 	}
 
@@ -151,7 +151,7 @@ func OaiStreamHandler(c *gin.Context, resp *http.Response, info *relaycommon.Rel
 
 	shouldSendLastResp := true
 	var lastStreamResponse dto.ChatCompletionsStreamResponse
-	err := json.Unmarshal(common.StringToByteSlice(lastStreamData), &lastStreamResponse)
+	err := common.DecodeJsonStr(lastStreamData, &lastStreamResponse)
 	if err == nil {
 		responseId = lastStreamResponse.Id
 		createAt = lastStreamResponse.Created
@@ -196,7 +196,7 @@ func OaiStreamHandler(c *gin.Context, resp *http.Response, info *relaycommon.Rel
 }
 
 func OpenaiHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo) (*dto.OpenAIErrorWithStatusCode, *dto.Usage) {
-	var simpleResponse dto.SimpleResponse
+	var simpleResponse dto.OpenAITextResponse
 	responseBody, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return service.OpenAIErrorWrapper(err, "read_response_body_failed", http.StatusInternalServerError), nil
@@ -205,16 +205,29 @@ func OpenaiHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayI
 	if err != nil {
 		return service.OpenAIErrorWrapper(err, "close_response_body_failed", http.StatusInternalServerError), nil
 	}
-	err = json.Unmarshal(responseBody, &simpleResponse)
+	err = common.DecodeJson(responseBody, &simpleResponse)
 	if err != nil {
 		return service.OpenAIErrorWrapper(err, "unmarshal_response_body_failed", http.StatusInternalServerError), nil
 	}
-	if simpleResponse.Error.Type != "" {
+	if simpleResponse.Error != nil && simpleResponse.Error.Type != "" {
 		return &dto.OpenAIErrorWithStatusCode{
-			Error:      simpleResponse.Error,
+			Error:      *simpleResponse.Error,
 			StatusCode: resp.StatusCode,
 		}, nil
 	}
+
+	switch info.RelayFormat {
+	case relaycommon.RelayFormatOpenAI:
+		break
+	case relaycommon.RelayFormatClaude:
+		claudeResp := service.ResponseOpenAI2Claude(&simpleResponse, info)
+		claudeRespStr, err := json.Marshal(claudeResp)
+		if err != nil {
+			return service.OpenAIErrorWrapper(err, "marshal_response_body_failed", http.StatusInternalServerError), nil
+		}
+		responseBody = claudeRespStr
+	}
+
 	// Reset response body
 	resp.Body = io.NopCloser(bytes.NewBuffer(responseBody))
 	// We shouldn't set the header before we parse the response body, because the parse part may fail.

service/error.go

@@ -60,7 +60,6 @@ func ClaudeErrorWrapper(err error, code string, statusCode int) *dto.ClaudeError
 	claudeError := dto.ClaudeError{
 		Message: text,
 		Type:    "new_api_error",
-		//Code:    code,
 	}
 	return &dto.ClaudeErrorWithStatusCode{
 		Error:      claudeError,