Merge branch 'feature/gemini-2.0-flash'

relay/adaptor/gemini/main.go

@@ -9,7 +9,6 @@ import (
 	"strings"
 
 	"github.com/gin-gonic/gin"
-
 	"github.com/songquanpeng/one-api/common"
 	"github.com/songquanpeng/one-api/common/config"
 	"github.com/songquanpeng/one-api/common/helper"
@@ -33,12 +32,6 @@ var mimeTypeMap = map[string]string{
 	"text":        "text/plain",
 }
 
-var toolChoiceTypeMap = map[string]string{
-	"none":     "NONE",
-	"auto":     "AUTO",
-	"required": "ANY",
-}
-
 // Setting safety to the lowest possible values since Gemini is already powerless enough
 func ConvertRequest(textRequest model.GeneralOpenAIRequest) *ChatRequest {
 	geminiRequest := ChatRequest{
@@ -97,24 +90,7 @@ func ConvertRequest(textRequest model.GeneralOpenAIRequest) *ChatRequest {
 			},
 		}
 	}
-	if textRequest.ToolChoice != nil {
-		geminiRequest.ToolConfig = &ToolConfig{
-			FunctionCallingConfig: FunctionCallingConfig{
-				Mode: "auto",
-			},
-		}
-		switch mode := textRequest.ToolChoice.(type) {
-		case string:
-			geminiRequest.ToolConfig.FunctionCallingConfig.Mode = toolChoiceTypeMap[mode]
-		case map[string]interface{}:
-			geminiRequest.ToolConfig.FunctionCallingConfig.Mode = "ANY"
-			if fn, ok := mode["function"].(map[string]interface{}); ok {
-				if name, ok := fn["name"].(string); ok {
-					geminiRequest.ToolConfig.FunctionCallingConfig.AllowedFunctionNames = []string{name}
-				}
-			}
-		}
-	}
+	shouldAddDummyModelMessage := false
 	for _, message := range textRequest.Messages {
 		content := ChatContent{
 			Role: message.Role,
@@ -152,21 +128,32 @@ func ConvertRequest(textRequest model.GeneralOpenAIRequest) *ChatRequest {
 		if content.Role == "assistant" {
 			content.Role = "model"
 		}
-		// Converting system prompt to SystemInstructions
+		// Converting system prompt to prompt from user for the same reason
 		if content.Role == "system" {
-			geminiRequest.SystemInstruction = &content
-			continue
+			shouldAddDummyModelMessage = true
+			if IsModelSupportSystemInstruction(textRequest.Model) {
+				geminiRequest.SystemInstruction = &content
+				geminiRequest.SystemInstruction.Role = ""
+				continue
+			} else {
+				content.Role = "user"
+			}
 		}
-		geminiRequest.Contents = append(geminiRequest.Contents, content)
-	}
 
-	// As of 2025-02-06, the newly released gemini 2.0 models do not support system_instruction,
-	// which can reasonably be considered a bug. Google may fix this issue in the future.
-	if geminiRequest.SystemInstruction != nil &&
-		strings.Contains(textRequest.Model, "-2.0") &&
-		textRequest.Model != "gemini-2.0-flash-exp" &&
-		textRequest.Model != "gemini-2.0-flash-thinking-exp-01-21" {
-		geminiRequest.SystemInstruction = nil
+		geminiRequest.Contents = append(geminiRequest.Contents, content)
+
+		// If a system message is the last message, we need to add a dummy model message to make gemini happy
+		if shouldAddDummyModelMessage {
+			geminiRequest.Contents = append(geminiRequest.Contents, ChatContent{
+				Role: "model",
+				Parts: []Part{
+					{
+						Text: "Okay",
+					},
+				},
+			})
+			shouldAddDummyModelMessage = false
+		}
 	}
 
 	return &geminiRequest
@@ -204,16 +191,10 @@ func (g *ChatResponse) GetResponseText() string {
 	if g == nil {
 		return ""
 	}
-	var builder strings.Builder
-	for _, candidate := range g.Candidates {
-		for idx, part := range candidate.Content.Parts {
-			if idx > 0 {
-				builder.WriteString("\n")
-			}
-			builder.WriteString(part.Text)
-		}
+	if len(g.Candidates) > 0 && len(g.Candidates[0].Content.Parts) > 0 {
+		return g.Candidates[0].Content.Parts[0].Text
 	}
-	return builder.String()
+	return ""
 }
 
 type ChatCandidate struct {
@@ -276,8 +257,8 @@ func responseGeminiChat2OpenAI(response *ChatResponse) *openai.TextResponse {
 				choice.Message.ToolCalls = getToolCalls(&candidate)
 			} else {
 				var builder strings.Builder
-				for idx, part := range candidate.Content.Parts {
-					if idx > 0 {
+				for _, part := range candidate.Content.Parts {
+					if i > 0 {
 						builder.WriteString("\n")
 					}
 					builder.WriteString(part.Text)