feat: support dify (close #299)

relay/channel/dify/relay-dify.go

@@ -0,0 +1,154 @@
+package dify
+
+import (
+	"bufio"
+	"encoding/json"
+	"github.com/gin-gonic/gin"
+	"io"
+	"net/http"
+	"one-api/common"
+	"one-api/dto"
+	relaycommon "one-api/relay/common"
+	"one-api/service"
+	"strings"
+)
+
+func requestOpenAI2Dify(request dto.GeneralOpenAIRequest) *DifyChatRequest {
+	content := ""
+	for _, message := range request.Messages {
+		if message.Role == "system" {
+			content += "SYSTEM: \n" + message.StringContent() + "\n"
+		} else if message.Role == "assistant" {
+			content += "ASSISTANT: \n" + message.StringContent() + "\n"
+		} else {
+			content += "USER: \n" + message.StringContent() + "\n"
+		}
+	}
+	mode := "blocking"
+	if request.Stream {
+		mode = "streaming"
+	}
+	user := request.User
+	if user == "" {
+		user = "api-user"
+	}
+	return &DifyChatRequest{
+		Inputs:           make(map[string]interface{}),
+		Query:            content,
+		ResponseMode:     mode,
+		User:             user,
+		AutoGenerateName: false,
+	}
+}
+
+func streamResponseDify2OpenAI(difyResponse DifyChunkChatCompletionResponse) *dto.ChatCompletionsStreamResponse {
+	response := dto.ChatCompletionsStreamResponse{
+		Object:  "chat.completion.chunk",
+		Created: common.GetTimestamp(),
+		Model:   "dify",
+	}
+	var choice dto.ChatCompletionsStreamResponseChoice
+	if difyResponse.Event == "workflow_started" {
+		choice.Delta.SetContentString("Workflow: " + difyResponse.Data.WorkflowId + "\n")
+	} else if difyResponse.Event == "node_started" {
+		choice.Delta.SetContentString("Node: " + difyResponse.Data.NodeId + "\n")
+	} else if difyResponse.Event == "message" {
+		choice.Delta.SetContentString(difyResponse.Answer)
+	}
+	response.Choices = append(response.Choices, choice)
+	return &response
+}
+
+func difyStreamHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo) (*dto.OpenAIErrorWithStatusCode, *dto.Usage) {
+	var responseText string
+	usage := &dto.Usage{}
+	scanner := bufio.NewScanner(resp.Body)
+	scanner.Split(bufio.ScanLines)
+
+	service.SetEventStreamHeaders(c)
+
+	for scanner.Scan() {
+		data := scanner.Text()
+		if len(data) < 5 || !strings.HasPrefix(data, "data:") {
+			continue
+		}
+		data = strings.TrimPrefix(data, "data:")
+		var difyResponse DifyChunkChatCompletionResponse
+		err := json.Unmarshal([]byte(data), &difyResponse)
+		if err != nil {
+			common.SysError("error unmarshalling stream response: " + err.Error())
+			continue
+		}
+		var openaiResponse dto.ChatCompletionsStreamResponse
+		if difyResponse.Event == "message_end" {
+			usage = &difyResponse.MetaData.Usage
+			break
+		} else if difyResponse.Event == "error" {
+			break
+		} else {
+			openaiResponse = *streamResponseDify2OpenAI(difyResponse)
+			if len(openaiResponse.Choices) != 0 {
+				responseText += openaiResponse.Choices[0].Delta.GetContentString()
+			}
+		}
+		err = service.ObjectData(c, openaiResponse)
+		if err != nil {
+			common.SysError(err.Error())
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		common.SysError("error reading stream: " + err.Error())
+	}
+	service.Done(c)
+	err := resp.Body.Close()
+	if err != nil {
+		//return service.OpenAIErrorWrapper(err, "close_response_body_failed", http.StatusInternalServerError), nil
+		common.SysError("close_response_body_failed: " + err.Error())
+	}
+	if usage.TotalTokens == 0 {
+		usage.PromptTokens = info.PromptTokens
+		usage.CompletionTokens, _ = service.CountTokenText("gpt-3.5-turbo", responseText)
+		usage.TotalTokens = usage.PromptTokens + usage.CompletionTokens
+	}
+	return nil, usage
+}
+
+func difyHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo) (*dto.OpenAIErrorWithStatusCode, *dto.Usage) {
+	var difyResponse DifyChatCompletionResponse
+	responseBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "read_response_body_failed", http.StatusInternalServerError), nil
+	}
+	err = resp.Body.Close()
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "close_response_body_failed", http.StatusInternalServerError), nil
+	}
+	err = json.Unmarshal(responseBody, &difyResponse)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "unmarshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+	fullTextResponse := dto.OpenAITextResponse{
+		Id:      difyResponse.ConversationId,
+		Object:  "chat.completion",
+		Created: common.GetTimestamp(),
+		Usage:   difyResponse.MetaData.Usage,
+	}
+	content, _ := json.Marshal(difyResponse.Answers)
+	choice := dto.OpenAITextResponseChoice{
+		Index: 0,
+		Message: dto.Message{
+			Role:    "assistant",
+			Content: content,
+		},
+		FinishReason: "stop",
+	}
+	fullTextResponse.Choices = append(fullTextResponse.Choices, choice)
+	jsonResponse, err := json.Marshal(fullTextResponse)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "marshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+	c.Writer.Header().Set("Content-Type", "application/json")
+	c.Writer.WriteHeader(resp.StatusCode)
+	_, err = c.Writer.Write(jsonResponse)
+	return nil, &difyResponse.MetaData.Usage
+}