feat: more role backend and admin/writer roles additions and adjustments

api/pkg/access/access.go

@@ -0,0 +1,34 @@
+package access
+
+import (
+	"RenewCMS/api/pkg/apperr"
+	"RenewCMS/internal/domain/role"
+	"context"
+	"errors"
+	"net/http"
+)
+
+type grantsContextKey struct{}
+
+func NewContext(ctx context.Context, grants role.GrantSet) context.Context {
+	return context.WithValue(ctx, grantsContextKey{}, grants)
+}
+
+func Grants(r *http.Request) role.GrantSet {
+	grants, _ := r.Context().Value(grantsContextKey{}).(role.GrantSet)
+	return grants
+}
+
+func WriteMissingPermission(w http.ResponseWriter, key string) {
+	w.Header().Set(apperr.MissingPermissionHeader, key)
+	http.Error(w, apperr.MissingPermissionErrorMessage, http.StatusForbidden)
+}
+
+func WriteIfMissingPermission(w http.ResponseWriter, err error) bool {
+	var missing role.MissingPermissionError
+	if !errors.As(err, &missing) {
+		return false
+	}
+	WriteMissingPermission(w, missing.Key)
+	return true
+}