fix(shipwrecks): small row and query fixes: era counts in one pass, pickers list only years with a wreck, no Portuguese default

- The legend counted each era twice, scanning every record eight times per
  row refresh; it now counts once.
- Each year picker listed every year from the oldest dated wreck (well over
  a thousand entries); it lists the years that have a wreck, plus the chosen
  ends.
- Labels fell back to Portuguese and links to Portuguese Wikipedia while the
  app ships 11 locales: labels now fall back through the app's languages
  after English, and a wreck with no English article links its Wikidata
  item, which lists the article in every language.

docs/CURRENT-STATE.md

@@ -178,7 +178,7 @@ cull GhostMaps uses, sized by deaths (a bigger toll draws on top) and coloured
 by era (a legend under the row): before 1900
 (ancient wrecks dated only by period count here), 1900–1945, after 1945, and
 date unknown. A period filter under the row picks a start year and an end year
-side by side (two pickers over the years in the data; a reversed pair is
+side by side (two pickers over the years that have a wreck; a reversed pair is
 stored swapped); undated wrecks show only when every year
 is selected. The filter is session-only (not in the share link). Clicking a marker opens a `stateless` card: deaths and
 survivors first, then the sinking date or year (or the archaeological dating) and

src/layers/shipwrecks/index.js

@@ -277,11 +277,20 @@ export function createShipwrecksLayer({
     picking?.unregisterPickOwner?.(SHIPWRECKS_LAYER_ID);
   }
 
-  function countOf(era) {
+  /** Wrecks shown per era, in one pass over the records. */
-    let count = 0;
+  function eraCounts() {
+    const counts = Object.fromEntries(SHIPWRECK_ERAS.map((era) => [era, 0]));
     for (const record of _records.values())
-      if (eraOf(record) === era && inPeriod(record, _range)) count++;
+      if (inPeriod(record, _range)) counts[eraOf(record)]++;
-    return count;
+    return counts;
+  }
+
+  /** The years that have a dated wreck, plus `extra` ones, newest first. */
+  function yearsInData(extra = []) {
+    const years = new Set(extra);
+    for (const record of _records.values())
+      if (Number.isInteger(record.year)) years.add(record.year);
+    return [...years].sort((a, b) => b - a);
   }
 
   /** The start and end year pickers, side by side. */
@@ -293,9 +302,13 @@ export function createShipwrecksLayer({
       : range.from === range.to
         ? String(range.from)
         : `${range.from}–${range.to}`;
-    const options = [];
+    // Only years with a wreck: a picker of every year since the oldest
-    for (let year = _extent.max; year >= _extent.min; year--)
+    // dated wreck would run to well over a thousand entries.
-      options.push({ value: year, label: String(year) });
+    // The chosen ends stay listed even when no wreck sank that year.
+    const options = yearsInData([range.from, range.to]).map((year) => ({
+      value: year,
+      label: String(year),
+    }));
     return {
       range: {
         id: 'period',
@@ -425,16 +438,17 @@ export function createShipwrecksLayer({
     },
 
     getRowControls() {
+      const counts = eraCounts();
       return {
         chips: [],
         ...periodControls(),
         // The colours are a legend: when the ship sank.
         legend: SHIPWRECK_ERAS.map((era) => ({
           label: t(ERA_LABELS[era]),
-          count: countOf(era),
+          count: counts[era],
           color: ERA_COLORS[era],
-          blurb: tn(countOf(era), '{count} wreck', '{count} wrecks', {
+          blurb: tn(counts[era], '{count} wreck', '{count} wrecks', {
-            count: formatNumber(countOf(era)),
+            count: formatNumber(counts[era]),
           }),
         })),
         info: t('EMODnet (European waters) · Wikidata (worldwide)'),

src/layers/shipwrecks/index.test.mjs

@@ -208,3 +208,39 @@ test('a click opens the card; a period that excludes the wreck closes it', async
   );
   assert.equal(h.layer.getStats().count, 1);
 });
+
+test('the year pickers list only years with a wreck, and each era is counted', async () => {
+  const h = harness({
+    snapshots: [
+      snapshot([
+        wreck('a', { year: 300 }),
+        wreck('b', { year: 1912 }),
+        wreck('c', { year: 1912 }),
+        wreck('d', { year: 1990 }),
+        wreck('e', { year: null }),
+      ]),
+    ],
+  });
+  h.layer.enable();
+  await h.layer.update();
+  let controls = h.layer.getRowControls();
+  assert.deepEqual(
+    controls.range.options.map((option) => option.value),
+    [1990, 1912, 300],
+  );
+  assert.deepEqual(
+    controls.legend.map((era) => era.count),
+    [1, 2, 1, 1],
+  );
+  h.layer.setParams({ from: 1900, to: 1950 });
+  controls = h.layer.getRowControls();
+  assert.deepEqual(
+    controls.range.options.map((option) => option.value),
+    [1990, 1950, 1912, 1900, 300],
+    'the chosen ends are listed too',
+  );
+  assert.deepEqual(
+    controls.legend.map((era) => era.count),
+    [0, 2, 0, 0],
+  );
+});

src/layers/shipwrecks/records.js

@@ -20,7 +20,7 @@ export const SHIPWRECK_SOURCES = Object.freeze(['emodnet', 'wikidata']);
  * come with their precision so a month-precise date is not shown as the 1st.
  * Only ship and event facts are read: no items about people.
  */
-export const WIKIDATA_QUERY = `SELECT ?item ?itemLabel ?itemDescription ?coord ?sunk ?sunkPrecision ?end ?endPrecision ?deaths ?survivors ?typeLabel ?enwiki ?ptwiki ?event WHERE {
+export const WIKIDATA_QUERY = `SELECT ?item ?itemLabel ?itemDescription ?coord ?sunk ?sunkPrecision ?end ?endPrecision ?deaths ?survivors ?typeLabel ?enwiki ?event WHERE {
   {
     ?item wdt:P31/wdt:P279* wd:Q852190 ; wdt:P625 ?coord ; wikibase:sitelinks ?links .
     FILTER(?links > 0)
@@ -35,8 +35,7 @@ export const WIKIDATA_QUERY = `SELECT ?item ?itemLabel ?itemDescription ?coord ?
   }
   OPTIONAL { ?item wdt:P1120 ?deaths }
   OPTIONAL { ?enwiki schema:about ?item ; schema:isPartOf <https://en.wikipedia.org/> }
-  OPTIONAL { ?ptwiki schema:about ?item ; schema:isPartOf <https://pt.wikipedia.org/> }
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en,mul,fr,de,es,it,pt,ru,uk,ja,zh,ar". }
-  SERVICE wikibase:label { bd:serviceParam wikibase:language "en,pt,mul". }
 }`;
 
 const MAX_TEXT = 160;
@@ -300,9 +299,9 @@ export function normalizeWikidataResults(payload) {
       country: null,
       originator: null,
       url:
-        wikiUrl(value('enwiki')) ||
+        // English Wikipedia, else the Wikidata item, which links the
-        wikiUrl(value('ptwiki')) ||
+        // article in every language that has one.
-        `https://www.wikidata.org/wiki/${qid}`,
+        wikiUrl(value('enwiki')) || `https://www.wikidata.org/wiki/${qid}`,
     });
   }
   return foldSinkingEvents([...byItem.values()]);

src/layers/shipwrecks/records.test.mjs

@@ -307,3 +307,8 @@ test('the query reads the end of service with its precision', () => {
   );
   assert.doesNotMatch(WIKIDATA_QUERY, /wdt:P576/);
 });
+
+test('labels and links do not default to one other language', () => {
+  assert.doesNotMatch(WIKIDATA_QUERY, /ptwiki|pt\.wikipedia/);
+  assert.match(WIKIDATA_QUERY, /wikibase:language "en,mul,/);
+});