gemini text generation

relay/channel/gemini/adaptor.go

@@ -10,6 +10,7 @@ import (
 	"one-api/dto"
 	"one-api/relay/channel"
 	relaycommon "one-api/relay/common"
+	"one-api/relay/constant"
 	"one-api/service"
 	"one-api/setting/model_setting"
 	"strings"
@@ -165,6 +166,11 @@ func (a *Adaptor) DoRequest(c *gin.Context, info *relaycommon.RelayInfo, request
 }
 
 func (a *Adaptor) DoResponse(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo) (usage any, err *dto.OpenAIErrorWithStatusCode) {
+	if info.RelayMode == constant.RelayModeGemini {
+		err, usage = GeminiTextGenerationHandler(c, resp, info)
+		return usage, err
+	}
+
 	if strings.HasPrefix(info.UpstreamModelName, "imagen") {
 		return GeminiImageHandler(c, resp, info)
 	}

relay/channel/gemini/relay-gemini-native.go

@@ -0,0 +1,77 @@
+package gemini
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"one-api/common"
+	"one-api/dto"
+	relaycommon "one-api/relay/common"
+	"one-api/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+func GeminiTextGenerationHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo) (*dto.OpenAIErrorWithStatusCode, *dto.Usage) {
+	// 读取响应体
+	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
+	}
+
+	if common.DebugEnabled {
+		println(string(responseBody))
+	}
+
+	// 解析为 Gemini 原生响应格式
+	var geminiResponse dto.GeminiTextGenerationResponse
+	err = common.DecodeJson(responseBody, &geminiResponse)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "unmarshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+
+	// 检查是否有候选响应
+	if len(geminiResponse.Candidates) == 0 {
+		return &dto.OpenAIErrorWithStatusCode{
+			Error: dto.OpenAIError{
+				Message: "No candidates returned",
+				Type:    "server_error",
+				Param:   "",
+				Code:    500,
+			},
+			StatusCode: resp.StatusCode,
+		}, nil
+	}
+
+	// 计算使用量（基于 UsageMetadata）
+	usage := dto.Usage{
+		PromptTokens:     geminiResponse.UsageMetadata.PromptTokenCount,
+		CompletionTokens: geminiResponse.UsageMetadata.CandidatesTokenCount,
+		TotalTokens:      geminiResponse.UsageMetadata.TotalTokenCount,
+	}
+
+	// 设置模型版本
+	if geminiResponse.ModelVersion == "" {
+		geminiResponse.ModelVersion = info.UpstreamModelName
+	}
+
+	// 直接返回 Gemini 原生格式的 JSON 响应
+	jsonResponse, err := json.Marshal(geminiResponse)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "marshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+
+	// 设置响应头并写入响应
+	c.Writer.Header().Set("Content-Type", "application/json")
+	c.Writer.WriteHeader(resp.StatusCode)
+	_, err = c.Writer.Write(jsonResponse)
+	if err != nil {
+		return service.OpenAIErrorWrapper(err, "write_response_failed", http.StatusInternalServerError), nil
+	}
+
+	return nil, &usage
+}