refactor progress

packages/list_utils/src/ListFormattingFallback.tsx

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2026 Fluxer Contributors
+ *
+ * This file is part of Fluxer.
+ *
+ * Fluxer is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Fluxer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import type {ListFormatType} from '@fluxer/list_utils/src/ListFormattingTypes';
+
+function getFallbackConjunction(type: ListFormatType): string {
+	if (type === 'disjunction') {
+		return 'or';
+	}
+	return 'and';
+}
+
+export function formatListWithFallback(items: ReadonlyArray<string>, type: ListFormatType): string {
+	if (items.length === 0) {
+		return '';
+	}
+
+	if (items.length === 1) {
+		return items[0] ?? '';
+	}
+
+	if (type === 'unit') {
+		return items.join(', ');
+	}
+
+	const conjunction = getFallbackConjunction(type);
+
+	if (items.length === 2) {
+		return `${items[0]} ${conjunction} ${items[1]}`;
+	}
+
+	const lastItem = items[items.length - 1];
+	const leadingItems = items.slice(0, -1).join(', ');
+	return `${leadingItems}, ${conjunction} ${lastItem}`;
+}