feat(cover): add cover letter name generation

backend/controllers/cover/cover.go

@@ -51,13 +51,13 @@ func Post(c *gin.Context) {
 	}
 
 	// Call chat and ask for cover letter nicely
-	coverLetter, err := chatgpt.GenerateCoverLetter(templates[0].Template, data.Application)
+	generatedCover, err := chatgpt.GenerateCoverLetter(templates[0].Template, data.Application)
 	if err != nil {
 		res.Error(c, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
-	res.Success(c, coverLetter)
+	res.Success(c, generatedCover)
 }
 
 func Put(c *gin.Context) {

backend/utils/chatgpt/chatgpt.go

@@ -10,9 +10,14 @@ import (
 	"time"
 )
 
+type ResponseFormat struct {
+	Type string `json:"type"`
+}
+
 type ChatRequest struct {
-	Model    string        `json:"model"`
-	Messages []ChatMessage `json:"messages"`
+	Model          string          `json:"model"`
+	Messages       []ChatMessage   `json:"messages"`
+	ResponseFormat *ResponseFormat `json:"response_format,omitempty"`
 }
 
 type ChatMessage struct {
@@ -20,40 +25,44 @@ type ChatMessage struct {
 	Content string `json:"content"`
 }
 
-func GenerateCoverLetter(templateHTML string, jobHTML string) (string, error) {
+type GeneratedCover struct {
+	Name  string `json:"name"`
+	Cover string `json:"cover"`
+}
+
+func GenerateCoverLetter(templateHTML string, jobHTML string) (GeneratedCover, error) {
 	apiKey := config.Env["CHATGPT_KEY"]
 	if apiKey == "" {
-		return "", errors.New("no API key chat gpt provided")
+		return GeneratedCover{}, errors.New("no API key chat gpt provided")
 	}
 
 	payload := ChatRequest{
 		Model: "gpt-4o", // o4-mini
+		ResponseFormat: &ResponseFormat{Type: "json_object"},
 		Messages: []ChatMessage{
 			{
 				Role:    "system",
-				Content: `You are a helpful assistant that fills out cover letter templates in HTML format. Replace all <...> tags like <company>, <experience>, etc., with appropriate content based on the job application.`,
+				Content: `You are a helpful assistant that fills out cover letter templates in HTML format and provides a name for it. Replace all <...> tags like <company>, <experience>, etc., with appropriate content based on the job application. You must respond with a JSON object with two keys: "name" for the cover letter title (e.g., "Cover Letter for a Software Engineer"), and "cover" for the filled HTML cover letter.`,
 			},
 			{
 				Role: "user",
-				Content: fmt.Sprintf(`Template: 
+				Content: fmt.Sprintf(`Template:
 %s
 
 Job description:
-%s
-
-Respond with ONLY the filled HTML cover letter.`, templateHTML, jobHTML),
+%s`, templateHTML, jobHTML),
 			},
 		},
 	}
 
 	body, err := json.Marshal(payload)
 	if err != nil {
-		return "", err
+		return GeneratedCover{}, err
 	}
 
 	req, err := http.NewRequest("POST", "https://api.openai.com/v1/chat/completions", bytes.NewBuffer(body))
 	if err != nil {
-		return "", err
+		return GeneratedCover{}, err
 	}
 
 	req.Header.Set("Content-Type", "application/json")
@@ -62,7 +71,7 @@ Respond with ONLY the filled HTML cover letter.`, templateHTML, jobHTML),
 	client := &http.Client{Timeout: 20 * time.Second}
 	res, err := client.Do(req)
 	if err != nil {
-		return "", err
+		return GeneratedCover{}, err
 	}
 	defer res.Body.Close()
 
@@ -75,12 +84,17 @@ Respond with ONLY the filled HTML cover letter.`, templateHTML, jobHTML),
 	}
 
 	if err := json.NewDecoder(res.Body).Decode(&result); err != nil {
-		return "", err
+		return GeneratedCover{}, err
 	}
 
 	if len(result.Choices) == 0 {
-		return "", fmt.Errorf("no response from GPT")
+		return GeneratedCover{}, fmt.Errorf("no response from GPT")
 	}
 
-	return result.Choices[0].Message.Content, nil
+	var cover GeneratedCover
+	if err := json.Unmarshal([]byte(result.Choices[0].Message.Content), &cover); err != nil {
+		return GeneratedCover{}, fmt.Errorf("failed to parse GPT response: %w", err)
+	}
+
+	return cover, nil
 }