feat: Update GptClient to accept model, improve README.md and use con…

…text in request

README.md

@@ -10,7 +10,7 @@
 
 > No more headaches with commit messages.
 
-AI-Commit is a command line tool that uses OpenAI's language generation capabilities to generate conventional commit messages for your Git repositories.
+AI-Commit is a command line tool that uses OpenAI's ChatGPT model to generate commit messages for your Git repositories. As a result, you can write meaningful commit messages without having to think about them.
 
 ## Prerequisites
 

client.go

@@ -23,29 +23,30 @@ type ChatCompleteRequest struct {
 
 type GptClient struct {
 	apiKey     string
+	model      string
 	httpClient *http.Client
 }
 
-const chatModel = "gpt-3.5-turbo"
 const chatEndpoint = "https://api.openai.com/v1/chat/completions"
 
-func NewGptClient(apiKey string) *GptClient {
+func NewGptClient(apiKey string, model string) *GptClient {
 	return &GptClient{
 		apiKey:     apiKey,
+		model:      model,
 		httpClient: http.DefaultClient,
 	}
 }
 
 func (c *GptClient) ChatComplete(ctx context.Context, messages []*Message) (string, error) {
 
 	request := &ChatCompleteRequest{
-		Model:    chatModel,
+		Model:    c.model,
 		Messages: messages,
 	}
 
 	payload, _ := json.Marshal(request)
 	payloadReader := bytes.NewReader(payload)
-	req, err := http.NewRequest("POST", chatEndpoint, payloadReader)
+	req, err := http.NewRequestWithContext(ctx, "POST", chatEndpoint, payloadReader)
 	if err != nil {
 		return "", err
 	}

main.go

@@ -21,6 +21,11 @@ func main() {
 		os.Exit(1)
 	}
 
+	model := os.Getenv("AI_COMMIT_MODEL")
+	if model == "" {
+		model = "gpt-3.5-turbo"
+	}
+
 	systemPrompt := os.Getenv("AI_COMMIT_SYSTEM_PROMPT")
 	if systemPrompt == "" {
 		systemPrompt = `You are a GitCommitGPT-4, You will help user to write commit message, commit message should be short (less than 100 chars), clean and meaningful. Only response the message.`
@@ -33,7 +38,7 @@ func main() {
 		},
 	}
 
-	client := NewGptClient(apiKey)
+	client := NewGptClient(apiKey, model)
 
 	// prepare the diff
 	diff, err := getDiff()