1 files changed, 94 insertions, 0 deletions
diff --git a/src/content/dependencies/generateAlbumSecondaryNavGroupPart.js b/src/content/dependencies/generateAlbumSecondaryNavGroupPart.js
new file mode 100644
index 00000000..22dfa51c
--- /dev/null
+++ b/src/content/dependencies/generateAlbumSecondaryNavGroupPart.js
@@ -0,0 +1,94 @@
+import {sortChronologically} from '#sort';
+import {atOffset} from '#sugar';
+
+export default {
+  contentDependencies: [
+    'generateColorStyleAttribute',
+    'generateSecondaryNavParentSiblingsPart',
+    'linkAlbumDynamically',
+    'linkGroup',
+  ],
+
+  extraDependencies: ['html'],
+
+  query(group, album) {
+    const query = {};
+
+    if (album.date) {
+      // Sort by latest first. This matches the sorting order used on group
+      // gallery pages, ensuring that previous/next matches moving up/down
+      // the gallery. Note that this makes the index offsets "backwards"
+      // compared to how latest-last chronological lists are accessed.
+      const albums =
+        sortChronologically(
+          group.albums.filter(album => album.date),
+          {latestFirst: true});
+
+      const currentIndex =
+        albums.indexOf(album);
+
+      query.previousAlbum =
+        atOffset(albums, currentIndex, +1);
+
+      query.nextAlbum =
+        atOffset(albums, currentIndex, -1);
+    }
+
+    return query;
+  },
+
+  relations: (relation, query, group, _album) => ({
+    parentSiblingsPart:
+      relation('generateSecondaryNavParentSiblingsPart'),
+
+    groupLink:
+      relation('linkGroup', group),
+
+    colorStyle:
+      relation('generateColorStyleAttribute', group.color),
+
+    previousAlbumLink:
+      (query.previousAlbum
+        ? relation('linkAlbumDynamically', query.previousAlbum)
+        : null),
+
+    nextAlbumLink:
+      (query.nextAlbum
+        ? relation('linkAlbumDynamically', query.nextAlbum)
+        : null),
+  }),
+
+  slots: {
+    mode: {
+      validate: v => v.is('album', 'track'),
+      default: 'album',
+    },
+  },
+
+  generate: (relations, slots) =>
+    relations.parentSiblingsPart.slots({
+      attributes: {class: 'group-nav-links'},
+
+      showPreviousNext: slots.mode === 'album',
+
+      colorStyle: relations.colorStyle,
+      mainLink: relations.groupLink,
+
+      previousLink:
+        (relations.previousAlbumLink
+          ? relations.previousAlbumLink.slots({
+              linkCommentaryPages: true,
+            })
+          : null),
+
+      nextLink:
+        (relations.nextAlbumLink
+          ? relations.nextAlbumLink.slots({
+              linkCommentaryPages: true,
+            })
+          : null),
+
+      stringsKey: 'albumSecondaryNav.group',
+      mainLinkOption: 'group',
+    }),
+};