feat: add gemini 1.5 flash support

Author: zhu327

README.md

@@ -99,10 +99,12 @@ Gemini-OpenAI-Proxy offers a straightforward way to integrate OpenAI functionali
 
    Model Mapping:
 
-   - gpt-3.5-turbo -> gemini-1.0-pro-latest
-   - gpt-4 -> gemini-1.0-ultra-latest
-   - gpt-4-turbo-preview -> gemini-1.5-pro-latest
-   - gpt-4-vision-preview -> gemini-1.0-pro-vision-latest
+   | GPT 模型 | Gemini 模型 |
+   |---|---|
+   | gpt-3.5-turbo | gemini-1.0-pro-latest |
+   | gpt-4 | gemini-1.5-flash-latest |
+   | gpt-4-turbo-preview | gemini-1.5-pro-latest |
+   | gpt-4-vision-preview | gemini-1.0-pro-vision-latest |
 
    If you wish to map `gpt-4-vision-preview` to `gemini-1.5-pro-latest`, you can configure the environment variable `GPT_4_VISION_PREVIEW = gemini-1.5-pro-latest`. This is because `gemini-1.5-pro-latest` now also supports multi-modal data.
 

pkg/adapter/chat.go

@@ -19,6 +19,7 @@ import (
 const (
 	Gemini1Pro       = "gemini-1.0-pro-latest"
 	Gemini1Dot5Pro   = "gemini-1.5-pro-latest"
+	Gemini1Dot5Flash = "gemini-1.5-flash-latest"
 	Gemini1ProVision = "gemini-1.0-pro-vision-latest"
 	Gemini1Ultra     = "gemini-1.0-ultra-latest"
 

pkg/adapter/struct.go

@@ -54,7 +54,7 @@ func (req *ChatCompletionRequest) ToGenaiModel() string {
 	case req.Model == openai.GPT4TurboPreview || req.Model == openai.GPT4Turbo1106 || req.Model == openai.GPT4Turbo0125:
 		return Gemini1Dot5Pro
 	case strings.HasPrefix(req.Model, openai.GPT4):
-		return Gemini1Ultra
+		return Gemini1Dot5Flash
 	default:
 		return Gemini1Pro
 	}