More things

frontend/app/composables/useRecentlyViewed.ts

@@ -1,12 +1,27 @@
 export interface ViewedArticle {
+  /** the article read, by its identity — the canonical version's slug. An
+   *  entry written before versions had addresses of their own may hold a
+   *  document's own slug, which the reader still resolves. */
   slug: string
   title: string
+  /** the language it was last read in, so a jump returns to that version.
+   *  Absent from entries written when one address stood for the whole article */
+  lang?: string
   viewedAt: number
 }
 
 const STORAGE_KEY = 'mathew-recently-viewed'
 const MAX_ENTRIES = 8
 
+/** where a jump leads: the version the article was last read in, or — for an
+ *  entry that recorded no language — the short address, which the reader turns
+ *  onto whichever version the slug speaks */
+export function viewedHref(viewed: Pick<ViewedArticle, 'slug' | 'lang'>): string {
+  return viewed.lang
+    ? versionHref(viewed.slug, viewed.lang)
+    : `/wiki/${encodeURIComponent(viewed.slug)}`
+}
+
 let loaded = false
 
 function readStored(): ViewedArticle[] {
@@ -36,14 +51,25 @@ export function useRecentlyViewed() {
     if (stored.length) viewed.value = stored
   })
 
-  function record(article: { slug: string; title: string }) {
+  function record(article: {
+    slug: string
+    title: string
+    baseSlug?: string | null
+    language?: string
+  }) {
+    /* filed by the article's identity and turned to the language it was read
+       in: an article read in two languages is still one article remembered
+       once, at the version it was last opened at */
+    const entry = {
+      slug: identityOf(article),
+      lang: articleLanguage(article),
+      title: article.title,
+    }
     /* merge with what's already saved so recording before the list has
        loaded (e.g. deep-linking straight to an article) can't clobber it */
     const base = viewed.value.length ? viewed.value : readStored()
-    viewed.value = [
-      { ...article, viewedAt: Date.now() },
-      ...base.filter((v) => v.slug !== article.slug),
-    ].slice(0, MAX_ENTRIES)
+    const fresh = { ...entry, viewedAt: Date.now() }
+    viewed.value = [fresh, ...base.filter((v) => v.slug !== entry.slug)].slice(0, MAX_ENTRIES)
     loaded = true
     try {
       localStorage.setItem(STORAGE_KEY, JSON.stringify(viewed.value))