add correct backfile

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

internal/pipeline/coingecko.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"strings"
+	"time"
 )
 
 // ResolveCryptoID résout un ticker crypto (ex: "BTC") en ID CoinGecko (ex: "bitcoin").
@@ -46,6 +47,48 @@ func ResolveCryptoID(ctx context.Context, apiKey, ticker string) (string, error)
 	return "", fmt.Errorf("no coingecko match for ticker %s", ticker)
 }
 
+// FetchCoinGeckoHistory récupère les prix EUR journaliers entre from et to pour un coin.
+func FetchCoinGeckoHistory(ctx context.Context, apiKey, coinID string, from, to time.Time) ([]PricePoint, error) {
+	baseURL := "https://api.coingecko.com/api/v3"
+	if apiKey != "" {
+		baseURL = "https://pro-api.coingecko.com/api/v3"
+	}
+
+	url := fmt.Sprintf("%s/coins/%s/market_chart/range?vs_currency=eur&from=%d&to=%d",
+		baseURL, coinID, from.Unix(), to.Unix())
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	if apiKey != "" {
+		req.Header.Set("x-cg-pro-api-key", apiKey)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	// Réponse : {"prices": [[timestamp_ms, price], ...]}
+	var raw struct {
+		Prices [][2]float64 `json:"prices"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&raw); err != nil {
+		return nil, fmt.Errorf("decode coingecko history: %w", err)
+	}
+
+	points := make([]PricePoint, 0, len(raw.Prices))
+	for _, p := range raw.Prices {
+		points = append(points, PricePoint{
+			At:    time.UnixMilli(int64(p[0])).UTC(),
+			Price: p[1],
+		})
+	}
+	return points, nil
+}
+
 // FetchCoinGeckoPrices récupère les prix EUR pour une liste d'IDs CoinGecko.
 // Le ticker stocké dans instrument_ticker_cache doit être l'ID CoinGecko (ex: "bitcoin", "ethereum").
 func FetchCoinGeckoPrices(ctx context.Context, apiKey string, coinIDs []string) (map[string]float64, error) {