1 files changed, 73 insertions, 0 deletions

diff --git a/viewer/src/services/itemComparators.ts b/viewer/src/services/itemComparators.ts
new file mode 100644
index 0000000..bd9accb
--- /dev/null
+++ b/viewer/src/services/itemComparators.ts
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+/* ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2019-2020  Guillaume FOUET
+--
+-- This program 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.
+--
+-- This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+import { TranslateResult } from "vue-i18n";
+import i18n from "@/plugins/i18n";
+
+export type ItemComparator = (left: Gallery.Item, right: Gallery.Item) => number;
+export type ItemSort = { text: TranslateResult; fn: ItemComparator };
+
+export default class ItemComparators {
+  static readonly ITEM_SORTS: Record<Gallery.ItemSortStr, ItemSort> = {
+    title_asc: {
+      text: i18n.t("command.sort.byTitleAsc"),
+      fn: ItemComparators.chain(ItemComparators.sortByTitleAsc, ItemComparators.sortByPathAsc),
+    },
+    date_asc: {
+      text: i18n.t("command.sort.byDateAsc"),
+      fn: ItemComparators.chain(ItemComparators.sortByDateAsc, ItemComparators.sortByPathAsc),
+    },
+    date_desc: {
+      text: i18n.t("command.sort.byDateDesc"),
+      fn: ItemComparators.reverse(ItemComparators.chain(ItemComparators.sortByDateAsc, ItemComparators.sortByPathAsc)),
+    },
+  };
+
+  static readonly DEFAULT = ItemComparators.ITEM_SORTS.date_asc;
+
+  static sortByPathAsc(left: Gallery.Item, right: Gallery.Item): number {
+    return left.path.localeCompare(right.path, undefined, {
+      sensitivity: "base",
+      ignorePunctuation: true,
+      numeric: true,
+    });
+  }
+
+  static sortByTitleAsc(left: Gallery.Item, right: Gallery.Item): number {
+    return left.title.localeCompare(right.title, undefined, {
+      sensitivity: "base",
+      ignorePunctuation: true,
+      numeric: true,
+    });
+  }
+
+  static sortByDateAsc(left: Gallery.Item, right: Gallery.Item): number {
+    return left.datetime.localeCompare(right.datetime); // TODO: handle timezones
+  }
+
+  static reverse(fn: ItemComparator): ItemComparator {
+    return (l, r) => -fn(l, r);
+  }
+
+  static chain(primary: ItemComparator, tieBreaker: ItemComparator): ItemComparator {
+    return (l, r) => {
+      const primaryComparison = primary(l, r);
+      return primaryComparison !== 0 ? primaryComparison : tieBreaker(l, r);
+    };
+  }
+}