feat: add frontend + backend + database to retrieve and compute news from Yahoo

backend/internal/ai/gemini.go

@@ -0,0 +1,84 @@
+package ai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+type geminiProvider struct {
+	apiKey string
+	model  string
+	client *http.Client
+}
+
+func newGemini(apiKey, model string) *geminiProvider {
+	if model == "" {
+		model = "gemini-2.0-flash"
+	}
+	return &geminiProvider{
+		apiKey: apiKey,
+		model:  model,
+		client: &http.Client{},
+	}
+}
+
+func (p *geminiProvider) Name() string { return "gemini" }
+
+func (p *geminiProvider) Summarize(ctx context.Context, prompt string) (string, error) {
+	url := fmt.Sprintf(
+		"https://generativelanguage.googleapis.com/v1beta/models/%s:generateContent?key=%s",
+		p.model, p.apiKey,
+	)
+	body := map[string]interface{}{
+		"contents": []map[string]interface{}{
+			{"parts": []map[string]string{{"text": prompt}}},
+		},
+	}
+	b, _ := json.Marshal(body)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(b))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	raw, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("gemini API error %d: %s", resp.StatusCode, raw)
+	}
+
+	var result struct {
+		Candidates []struct {
+			Content struct {
+				Parts []struct {
+					Text string `json:"text"`
+				} `json:"parts"`
+			} `json:"content"`
+		} `json:"candidates"`
+	}
+	if err := json.Unmarshal(raw, &result); err != nil {
+		return "", err
+	}
+	if len(result.Candidates) == 0 || len(result.Candidates[0].Content.Parts) == 0 {
+		return "", nil
+	}
+	return result.Candidates[0].Content.Parts[0].Text, nil
+}
+
+func (p *geminiProvider) ListModels(_ context.Context) ([]string, error) {
+	return []string{
+		"gemini-2.0-flash",
+		"gemini-2.0-flash-lite",
+		"gemini-1.5-pro",
+		"gemini-1.5-flash",
+	}, nil
+}