feat: add batch processing with injected db and api

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/lib/process.js

@@ -0,0 +1,73 @@
+import { computeScore, shouldSave } from './score.js';
+
+export const RECHECK_MS = 24 * 60 * 60 * 1000;
+
+const watchUrl = (videoId) => `https://www.youtube.com/watch?v=${videoId}`;
+
+function isFresh(checkedAt, nowMs) {
+  return checkedAt !== undefined && nowMs - Date.parse(checkedAt) < RECHECK_MS;
+}
+
+export async function processBatch(items, { settings, db, api, now = new Date() }) {
+  const nowMs = now.getTime();
+  const nowIso = now.toISOString();
+  const byId = new Map(items.map((item) => [item.videoId, item]));
+
+  const seen = await db.getSeen([...byId.keys()]);
+  const due = [...byId.values()].filter(
+    (item) => item.vidiqScore !== null || !isFresh(seen.get(item.videoId)?.checkedAt, nowMs),
+  );
+  if (due.length === 0) return { checked: 0, saved: 0 };
+
+  const { videos, missingIds } = await api.fetchVideos(due.map((item) => item.videoId));
+
+  const channelIds = [...new Set(videos.map((video) => video.channelId))];
+  const cachedChannels = await db.getChannels(channelIds);
+  const staleIds = channelIds.filter((id) => !isFresh(cachedChannels.get(id)?.fetchedAt, nowMs));
+  const fetchedChannels = staleIds.length > 0 ? await api.fetchChannels(staleIds) : [];
+  const channelRecords = fetchedChannels.map((channel) => ({ ...channel, fetchedAt: nowIso }));
+  const channels = new Map(cachedChannels);
+  for (const record of channelRecords) channels.set(record.channelId, record);
+
+  const existing = await db.getOutliers(videos.map((video) => video.videoId));
+  const outliers = [];
+  for (const video of videos) {
+    const item = byId.get(video.videoId);
+    const previous = existing.get(video.videoId);
+    const channel = channels.get(video.channelId);
+    const subscribers = channel?.subscribers ?? null;
+    const score = computeScore(video.views, subscribers);
+    const vidiqScore = item.vidiqScore ?? previous?.vidiqScore ?? null;
+
+    if (!previous && !shouldSave({ views: video.views, score, vidiqScore }, settings)) continue;
+
+    outliers.push({
+      videoId: video.videoId,
+      title: video.title,
+      url: watchUrl(video.videoId),
+      thumbnailUrl: video.thumbnailUrl,
+      channelId: video.channelId,
+      channelTitle: video.channelTitle,
+      channelUrl: channel?.url ?? `https://www.youtube.com/channel/${video.channelId}`,
+      subscribers,
+      views: video.views,
+      publishedAt: video.publishedAt,
+      durationSec: video.durationSec,
+      isShort: item.viaShortsUrl || previous?.isShort || false,
+      score,
+      vidiqScore,
+      foundOn: previous?.foundOn ?? item.page,
+      firstSeenAt: previous?.firstSeenAt ?? nowIso,
+      updatedAt: nowIso,
+    });
+  }
+
+  // Results first, `seen` last: if anything above throws, the ids are retried later.
+  await db.putChannels(channelRecords);
+  await db.putOutliers(outliers);
+  await db.putSeen([
+    ...videos.map((video) => ({ videoId: video.videoId, checkedAt: nowIso, status: 'ok' })),
+    ...missingIds.map((videoId) => ({ videoId, checkedAt: nowIso, status: 'unavailable' })),
+  ]);
+  return { checked: due.length, saved: outliers.length };
+}