local conversion

site/src/lib/dataloader.ts

@@ -0,0 +1,123 @@
+/**
+ * Data access abstraction layer.
+ *
+ * All Svelte components load BAS data through these functions instead of
+ * calling fetch() directly. Each function merges server/bundled data with
+ * any activities stored locally in IndexedDB (via localstore.ts), so the
+ * app works the same whether it is connected to a cloud instance, running
+ * offline, or somewhere in between.
+ *
+ * Design notes:
+ * - Server fetch and IDB read run concurrently (Promise.allSettled).
+ * - If the server is unreachable, local-only data is returned.
+ * - If IDB is empty, pure server data is returned — zero overhead.
+ * - Local activities override server ones with the same ID (local is authoritative
+ *   for anything the user recorded or converted on this device).
+ */
+
+import type { ActivityDetail, ActivitySummary, BASIndex } from './types';
+import { listLocalActivities } from './localstore';
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+async function fetchJSON<T>(url: string): Promise<T> {
+  const r = await fetch(url);
+  if (!r.ok) throw new Error(`HTTP ${r.status}`);
+  return r.json() as Promise<T>;
+}
+
+async function idbGetActivity(id: string): Promise<ActivityDetail | null> {
+  // Inline IDB read — avoids importing openDB into every caller
+  return new Promise(resolve => {
+    try {
+      const req = indexedDB.open('bincio', 1);
+      req.onsuccess = e => {
+        const db: IDBDatabase = (e.target as IDBOpenDBRequest).result;
+        const tx = db.transaction('files', 'readonly');
+        const get = tx.objectStore('files').get(`/data/activities/${id}.json`);
+        get.onsuccess = ge => resolve((ge.target as IDBRequest).result?.data ?? null);
+        get.onerror   = () => resolve(null);
+      };
+      req.onerror = () => resolve(null);
+    } catch {
+      resolve(null);
+    }
+  });
+}
+
+function emptyIndex(): BASIndex {
+  return {
+    bas_version: '1.0',
+    owner: { handle: 'unknown', display_name: '' },
+    generated_at: '',
+    shards: [],
+    activities: [],
+  };
+}
+
+// ── Public API ────────────────────────────────────────────────────────────────
+
+/**
+ * Load the activity index, merging the server's copy with any locally-stored
+ * activities. Local entries override server entries with the same ID.
+ */
+export async function loadIndex(baseUrl: string): Promise<BASIndex> {
+  const [serverResult, localResult] = await Promise.allSettled([
+    fetchJSON<BASIndex>(`${baseUrl}data/index.json`),
+    listLocalActivities(),
+  ]);
+
+  const server = serverResult.status === 'fulfilled' ? serverResult.value : null;
+  const local  = localResult.status  === 'fulfilled' ? localResult.value  : [];
+
+  if (local.length === 0) return server ?? emptyIndex();
+  if (!server)            return { ...emptyIndex(), activities: local as ActivitySummary[] };
+
+  // Local overrides server for the same ID; new local entries are appended
+  const merged = new Map<string, ActivitySummary>();
+  for (const a of server.activities ?? []) merged.set(a.id, a);
+  for (const a of local as ActivitySummary[]) merged.set(a.id, a);
+
+  return {
+    ...server,
+    activities: [...merged.values()].sort(
+      (a, b) => (b.started_at ?? '').localeCompare(a.started_at ?? ''),
+    ),
+  };
+}
+
+/**
+ * Load a single activity detail, checking IndexedDB first so locally-converted
+ * activities are available offline.
+ *
+ * @param id        Activity ID (used for the IDB lookup)
+ * @param detailUrl Relative path from the BAS index (e.g. "activities/id.json")
+ * @param baseUrl   Site base URL
+ */
+export async function loadActivity(
+  id:        string,
+  detailUrl: string,
+  baseUrl:   string,
+): Promise<ActivityDetail | null> {
+  // IDB first — instant and works offline
+  const cached = await idbGetActivity(id);
+  if (cached) return cached;
+
+  try {
+    return await fetchJSON<ActivityDetail>(`${baseUrl}data/${detailUrl}`);
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Load athlete profile. Athlete data is not stored locally yet, so this is
+ * always a network fetch with a graceful null on failure.
+ */
+export async function loadAthlete(baseUrl: string): Promise<Record<string, unknown> | null> {
+  try {
+    return await fetchJSON(`${baseUrl}data/athlete.json`);
+  } catch {
+    return null;
+  }
+}