feat(ia): implement Smart Digest and fix UI alignment

internal/service/ai.go

@@ -0,0 +1,107 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+)
+
+// AIService handles interactions with AI providers (OpenRouter).
+type AIService struct {
+	apiKey string
+	client *http.Client
+}
+
+// NewAIService creates a new AI service.
+func NewAIService() *AIService {
+	return &AIService{
+		apiKey: os.Getenv("OPENROUTER_API_KEY"),
+		client: &http.Client{},
+	}
+}
+
+// OpenRouterRequest represents the request body for OpenRouter.
+type OpenRouterRequest struct {
+	Model    string    `json:"model"`
+	Messages []Message `json:"messages"`
+}
+
+// Message represents a message in the conversation.
+type Message struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+// OpenRouterResponse represents the response body from OpenRouter.
+type OpenRouterResponse struct {
+	Choices []struct {
+		Message Message `json:"message"`
+	} `json:"choices"`
+	Error *struct {
+		Message string `json:"message"`
+	} `json:"error,omitempty"`
+}
+
+// Summarize generates a concise summary of the given content.
+func (s *AIService) Summarize(ctx context.Context, content string) (string, error) {
+	if s.apiKey == "" {
+		return "", fmt.Errorf("OPENROUTER_API_KEY not set")
+	}
+
+	prompt := fmt.Sprintf("Résume l'article suivant en 3 à 5 phrases percutantes. Sois direct et informatif :\n\n%s", content)
+
+	reqBody := OpenRouterRequest{
+		Model: "google/gemini-2.0-flash-001", // Économique et performant
+		Messages: []Message{
+			{Role: "user", Content: prompt},
+		},
+	}
+
+	jsonData, err := json.Marshal(reqBody)
+	if err != nil {
+		return "", fmt.Errorf("marshaling request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", "https://openrouter.ai/api/v1/chat/completions", bytes.NewBuffer(jsonData))
+	if err != nil {
+		return "", fmt.Errorf("creating request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+s.apiKey)
+	req.Header.Set("HTTP-Referer", "https://github.com/michael/flowreader") // Optionnel pour OpenRouter
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("sending request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("reading response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("API error (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	var orResp OpenRouterResponse
+	if err := json.Unmarshal(body, &orResp); err != nil {
+		return "", fmt.Errorf("unmarshaling response: %w", err)
+	}
+
+	if orResp.Error != nil {
+		return "", fmt.Errorf("OpenRouter error: %s", orResp.Error.Message)
+	}
+
+	if len(orResp.Choices) == 0 {
+		return "", fmt.Errorf("no summary generated")
+	}
+
+	return orResp.Choices[0].Message.Content, nil
+}