add owner handle

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

internal/auth/auth.go

@@ -0,0 +1,41 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strconv"
+)
+
+type contextKey struct{}
+
+func WithOwner(ctx context.Context, ownerID int32) context.Context {
+	return context.WithValue(ctx, contextKey{}, ownerID)
+}
+
+func OwnerFromContext(ctx context.Context) (int32, bool) {
+	id, ok := ctx.Value(contextKey{}).(int32)
+	return id, ok
+}
+
+// Middleware extrait X-Owner-ID du header et l'injecte dans le contexte.
+// Pour le dev, c'est l'ID numérique de l'owner. À remplacer par JWT en prod.
+func Middleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		v := r.Header.Get("X-Owner-ID")
+		if v == "" {
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusUnauthorized)
+			fmt.Fprintln(w, `{"error":"missing X-Owner-ID header"}`)
+			return
+		}
+		id, err := strconv.Atoi(v)
+		if err != nil || id <= 0 {
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusUnauthorized)
+			fmt.Fprintln(w, `{"error":"invalid X-Owner-ID"}`)
+			return
+		}
+		next.ServeHTTP(w, r.WithContext(WithOwner(r.Context(), int32(id))))
+	})
+}