feat: refactor response parsing logic to support multiple formats (#782)

* feat: Refactor response parsing logic to support multiple formats

The parsing logic for responses in relay.go and relay-audio.go was refactored to support multiple response formats - 'json', 'text', 'srt', 'verbose_json', and 'vtt'. The existing `WhisperResponse` struct was renamed to `WhisperJsonResponse` and a new struct `WhisperVerboseJsonResponse` was added to support the 'verbose_json' format. Additional parsing functions were added to extract text from these new response types. This change was necessary to make the parsing logic more flexible and extendable for different types of responses.

* chore: update name

---------

Co-authored-by: JustSong <songquanpeng@foxmail.com>

controller/relay-audio.go

@@ -1,6 +1,7 @@
 package controller
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"encoding/json"
@@ -102,7 +103,13 @@ func relayAudioHelper(c *gin.Context, relayMode int) *OpenAIErrorWithStatusCode
 		fullRequestURL = fmt.Sprintf("%s/openai/deployments/%s/audio/transcriptions?api-version=%s", baseURL, audioModel, apiVersion)
 	}
 
-	requestBody := c.Request.Body
+	requestBody := &bytes.Buffer{}
+	_, err = io.Copy(requestBody, c.Request.Body)
+	if err != nil {
+		return errorWrapper(err, "new_request_body_failed", http.StatusInternalServerError)
+	}
+	c.Request.Body = io.NopCloser(bytes.NewBuffer(requestBody.Bytes()))
+	responseFormat := c.DefaultPostForm("response_format", "json")
 
 	req, err := http.NewRequest(c.Request.Method, fullRequestURL, requestBody)
 	if err != nil {
@@ -144,12 +151,33 @@ func relayAudioHelper(c *gin.Context, relayMode int) *OpenAIErrorWithStatusCode
 		if err != nil {
 			return errorWrapper(err, "close_response_body_failed", http.StatusInternalServerError)
 		}
-		var whisperResponse WhisperResponse
-		err = json.Unmarshal(responseBody, &whisperResponse)
-		if err != nil {
-			return errorWrapper(err, "unmarshal_response_body_failed", http.StatusInternalServerError)
+
+		var openAIErr TextResponse
+		if err = json.Unmarshal(responseBody, &openAIErr); err == nil {
+			if openAIErr.Error.Message != "" {
+				return errorWrapper(fmt.Errorf("type %s, code %v, message %s", openAIErr.Error.Type, openAIErr.Error.Code, openAIErr.Error.Message), "request_error", http.StatusInternalServerError)
+			}
 		}
-		quota = countTokenText(whisperResponse.Text, audioModel)
+
+		var text string
+		switch responseFormat {
+		case "json":
+			text, err = getTextFromJSON(responseBody)
+		case "text":
+			text, err = getTextFromText(responseBody)
+		case "srt":
+			text, err = getTextFromSRT(responseBody)
+		case "verbose_json":
+			text, err = getTextFromVerboseJSON(responseBody)
+		case "vtt":
+			text, err = getTextFromVTT(responseBody)
+		default:
+			return errorWrapper(errors.New("unexpected_response_format"), "unexpected_response_format", http.StatusInternalServerError)
+		}
+		if err != nil {
+			return errorWrapper(err, "get_text_from_body_err", http.StatusInternalServerError)
+		}
+		quota = countTokenText(text, audioModel)
 		resp.Body = io.NopCloser(bytes.NewBuffer(responseBody))
 	}
 	if resp.StatusCode != http.StatusOK {
@@ -187,3 +215,48 @@ func relayAudioHelper(c *gin.Context, relayMode int) *OpenAIErrorWithStatusCode
 	}
 	return nil
 }
+
+func getTextFromVTT(body []byte) (string, error) {
+	return getTextFromSRT(body)
+}
+
+func getTextFromVerboseJSON(body []byte) (string, error) {
+	var whisperResponse WhisperVerboseJSONResponse
+	if err := json.Unmarshal(body, &whisperResponse); err != nil {
+		return "", fmt.Errorf("unmarshal_response_body_failed err :%w", err)
+	}
+	return whisperResponse.Text, nil
+}
+
+func getTextFromSRT(body []byte) (string, error) {
+	scanner := bufio.NewScanner(strings.NewReader(string(body)))
+	var builder strings.Builder
+	var textLine bool
+	for scanner.Scan() {
+		line := scanner.Text()
+		if textLine {
+			builder.WriteString(line)
+			textLine = false
+			continue
+		} else if strings.Contains(line, "-->") {
+			textLine = true
+			continue
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+	return builder.String(), nil
+}
+
+func getTextFromText(body []byte) (string, error) {
+	return strings.TrimSuffix(string(body), "\n"), nil
+}
+
+func getTextFromJSON(body []byte) (string, error) {
+	var whisperResponse WhisperJSONResponse
+	if err := json.Unmarshal(body, &whisperResponse); err != nil {
+		return "", fmt.Errorf("unmarshal_response_body_failed err :%w", err)
+	}
+	return whisperResponse.Text, nil
+}