Official release dates from MangaUpdates; peers lower ecosystem dates (BL-0048, BL-0049)

- scraper/metadata/release-dates.js fills x-dates.release from MangaUpdates
  publisher releases. MangaUpdates also lists English back-catalog re-releases,
  so a date is kept only inside the AniList original run, when no scanlation or
  source upload is more than 4 days earlier, and when it fits the release order
  (no lower chapter dated after a higher one). Seasons that restart chapter
  numbers are skipped; dates this job wrote and no longer accepts are withdrawn.
- The scraper refreshes ongoing series nightly before its update checks, only
  while no download runs, and bumps the publish revision so the reader reconciles.
- tools/release-dates.js for a whole library (dry run default). Production dry
  run: 728 chapters dated (Kagurabachi, JJK, Chainsaw Man, One Piece from 928).
- Peer sync: chapters this library already has adopt a peer's earlier ecosystem
  date (job result ecosystemLowered); the peer listing now carries dates.

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

scraper/metadata/release-dates.js

@@ -0,0 +1,180 @@
+'use strict';
+// Official chapter release dates (BL-0048) from MangaUpdates publisher releases.
+// MangaUpdates also lists English digital re-releases of old chapters as "official"
+// (Naruto ch. 700 shows 2020; it came out in Japan in 2014). A date is accepted only when
+//   1. it lies inside the work's original run (AniList start - 7 days ... end + 30 days), and
+//   2. nothing shows the chapter earlier: no scanlation release in MangaUpdates and no
+//      source upload (bulk or not) more than EARLY_TOLERANCE_DAYS before it, and
+//   3. it fits the release order (see officialDates).
+// Simulpub releases pass all three; back-catalog re-releases fail at least one.
+const fs = require('node:fs').promises;
+const path = require('node:path');
+const crypto = require('node:crypto');
+const { parseKey } = require('../../chapter-identity');
+const { writeJsonAtomic } = require('../lib/json-file');
+
+const DAY = 864e5;
+const EARLY_TOLERANCE_DAYS = 4; // early scans and source uploads of weekly series arrive 1-3 days before the official date
+const ORDER_TOLERANCE_DAYS = 2; // double releases and day-granular dates may put a lower chapter a day or two later
+const OFFICIAL = new Set(['viz', 'viz media', 'manga plus', 'mangaplus', 'shueisha', 'kodansha', 'kodansha usa', 'k manga',
+  'yen press', 'seven seas', 'square enix', 'square enix manga', 'manga up!', 'comikey', 'azuki', 'tappytoon', 'webtoon',
+  'line webtoon', 'webtoons', 'tapas', 'pocket comics', 'manta', 'lezhin', 'lezhin comics', 'j-novel club', 'dark horse',
+  'vertical', 'denpa', 'tokyopop', 'ize press', 'one peace books', 'inky pen', 'kakaopage', 'kakao webtoon', 'naver webtoon']);
+const UA = 'MangaCircus/1.0 (self-hosted manga reader; chapter release dates)';
+const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
+const norm = value => String(value || '').toLowerCase().normalize('NFKD').replace(/[^a-z0-9]+/g, '');
+// "001", "1.50" and "1" are the same chapter; ranges, volumes and letters are not single chapters.
+const chapterKey = value => (/^\s*\d+(?:\.\d+)?\s*$/.test(String(value ?? '')) ? String(Number(value)) : null);
+const isOfficial = groups => groups.some(name => OFFICIAL.has(String(name).toLowerCase().trim()));
+
+async function cached(cacheDir, key, maxAgeMs, load) {
+  const file = cacheDir && path.join(cacheDir, crypto.createHash('sha256').update(key).digest('hex').slice(0, 32) + '.json');
+  if (file) {
+    try {
+      const stat = await fs.stat(file);
+      if (Date.now() - stat.mtimeMs < maxAgeMs) return JSON.parse(await fs.readFile(file, 'utf8'));
+    } catch { /* not cached */ }
+  }
+  const value = await load();
+  if (file) { await fs.mkdir(cacheDir, { recursive: true }); await writeJsonAtomic(file, value); }
+  return value;
+}
+
+class ReleaseDateSources {
+  constructor(options = {}) {
+    this.cacheDir = options.cacheDir || null;
+    this.minGapMs = options.minGapMs ?? 1100;
+    this.fetch = options.fetch || globalThis.fetch;
+    this.last = 0;
+  }
+  async request(url, body) {
+    const wait = this.last + this.minGapMs - Date.now();
+    if (wait > 0) await sleep(wait);
+    this.last = Date.now();
+    const response = await this.fetch(url, { method: 'POST', headers: { 'content-type': 'application/json', 'user-agent': UA },
+      body: JSON.stringify(body), signal: AbortSignal.timeout(30000) });
+    if (!response.ok) throw new Error(`${new URL(url).hostname} HTTP ${response.status}`);
+    return response.json();
+  }
+  // MangaUpdates series whose matched name equals one of the manga's titles and whose year fits.
+  async findSeries(meta) {
+    const titles = [meta.title, ...(Array.isArray(meta.altTitles) ? meta.altTitles : [])].map(norm).filter(Boolean);
+    const year = Number(meta.year) || null;
+    const result = await cached(this.cacheDir, `mu-search:${meta.title}`, 30 * DAY,
+      () => this.request('https://api.mangaupdates.com/v1/series/search', { search: String(meta.title || ''), perpage: 10 }));
+    for (const hit of result.results || []) {
+      const record = hit.record || {}, hitYear = Number(record.year) || null;
+      if (year && hitYear && Math.abs(hitYear - year) > 1) continue;
+      if ([record.title, hit.hit_title].map(norm).some(name => name && titles.includes(name))) {
+        return { id: String(record.series_id), title: record.title, url: record.url || null };
+      }
+    }
+    return null;
+  }
+  async releases(seriesId, { pages = Infinity, maxAgeMs = 7 * DAY } = {}) {
+    return cached(this.cacheDir, `mu-releases:${seriesId}:${pages}`, maxAgeMs, async () => {
+      const rows = [];
+      for (let page = 1; page <= pages; page++) {
+        const result = await this.request('https://api.mangaupdates.com/v1/releases/search',
+          { search: String(seriesId), search_type: 'series', perpage: 100, page, orderby: 'date' });
+        for (const { record } of result.results || []) {
+          if (record?.release_date) rows.push({ chapter: record.chapter, date: record.release_date, groups: (record.groups || []).map(g => g.name) });
+        }
+        if (!result.results?.length || page * 100 >= (result.total_hits || 0)) break;
+      }
+      return rows;
+    });
+  }
+  async originalRun(anilistId) {
+    if (!anilistId) return null;
+    const result = await cached(this.cacheDir, `anilist-run:${anilistId}`, 30 * DAY, () => this.request('https://graphql.anilist.co', {
+      query: 'query ($id: Int) { Media(id: $id, type: MANGA) { status startDate { year month day } endDate { year month day } } }',
+      variables: { id: Number(anilistId) },
+    }));
+    const media = result.data?.Media;
+    if (!media) return null;
+    const date = (d, end) => (d?.year ? Date.UTC(d.year, (d.month || (end ? 12 : 1)) - 1, d.day || (end ? 28 : 1)) : null);
+    return { status: media.status, start: date(media.startDate, false), end: media.status === 'RELEASING' ? null : date(media.endDate, true) };
+  }
+}
+
+// Pure decision: official dates per chapter key, with the reasons others were rejected.
+// evidence: Map chapterKey -> earliest other time (ms) the library knows for that chapter.
+function officialDates(releases, run, evidence = new Map()) {
+  const official = new Map(), scans = new Map();
+  for (const row of releases) {
+    const key = chapterKey(row.chapter), time = Date.parse(row.date);
+    if (!key || !Number.isFinite(time)) continue;
+    const target = isOfficial(row.groups) ? official : scans;
+    const prior = target.get(key);
+    if (!prior || time < prior.time) target.set(key, { time, date: String(row.date).slice(0, 10), groups: row.groups });
+  }
+  const accepted = new Map(), rejected = { outsideRun: 0, earlier: 0, outOfOrder: 0, noRun: 0 };
+  // 3. Walking down from the newest chapter, release dates never rise again: a lower chapter
+  //    dated after a higher one is a back-catalog re-release (One Piece ch. 8 on 2019-02-06).
+  let ceiling = Infinity;
+  for (const [key, item] of [...official].sort((a, b) => Number(b[0]) - Number(a[0]))) {
+    if (!run || !run.start) { rejected.noRun++; continue; }
+    if (item.time < run.start - 7 * DAY || (run.end && item.time > run.end + 30 * DAY)) { rejected.outsideRun++; continue; }
+    const earliest = Math.min(scans.get(key)?.time ?? Infinity, evidence.get(key) ?? Infinity);
+    if (earliest < item.time - EARLY_TOLERANCE_DAYS * DAY) { rejected.earlier++; continue; }
+    if (item.time > ceiling + ORDER_TOLERANCE_DAYS * DAY) { rejected.outOfOrder++; continue; }
+    ceiling = Math.min(ceiling, item.time);
+    accepted.set(key, { at: item.date, precision: 'day', source: `MangaUpdates · ${item.groups.join(', ')}` });
+  }
+  return { accepted, rejected, officialCount: official.size };
+}
+
+// Chapter version folders of one manga with their numeric chapter key.
+async function chapterVersions(mangaDir) {
+  const out = [];
+  const dirs = async dir => (await fs.readdir(dir, { withFileTypes: true })).filter(e => e.isDirectory() && !e.name.startsWith('.')).map(e => e.name);
+  for (const book of await dirs(mangaDir)) {
+    if (!parseKey(book)) continue;
+    for (const chapter of await dirs(path.join(mangaDir, book))) {
+      const parsed = parseKey(chapter);
+      if (!parsed || parsed.x) continue; // extras and specials have no chapter number to match
+      const file = path.join(mangaDir, book, chapter, 'chapter.json');
+      let meta;
+      try { meta = JSON.parse(await fs.readFile(file, 'utf8')); } catch { continue; }
+      out.push({ key: chapterKey(parsed.num), book, file, meta });
+    }
+  }
+  return out;
+}
+
+// Look up, decide and (with apply) write x-dates.release for one manga folder.
+async function refreshMangaReleaseDates(mangaDir, sources, { apply = false, pages = Infinity, maxAgeMs } = {}) {
+  const meta = JSON.parse(await fs.readFile(path.join(mangaDir, 'manga.json'), 'utf8').catch(() => '{}'));
+  const versions = await chapterVersions(mangaDir);
+  const summary = { manga: path.basename(mangaDir), series: null, chapters: new Set(versions.map(v => v.key)).size, official: 0, accepted: 0, written: 0, cleared: 0, rejected: null, ambiguous: false };
+  // Seasons that restart at chapter 1 cannot be matched to MangaUpdates' running numbers.
+  const books = new Map();
+  for (const version of versions) books.set(version.key, (books.get(version.key) || new Set()).add(version.book));
+  if ([...books.values()].some(set => set.size > 1)) { summary.ambiguous = true; return summary; }
+  const series = await sources.findSeries(meta);
+  if (!series) return summary;
+  summary.series = series;
+  const run = await sources.originalRun(meta['x-anilist']?.id || meta['x-scraper']?.ids?.anilist);
+  const evidence = new Map();
+  for (const version of versions) {
+    const time = Date.parse(version.meta['x-dates']?.source?.at);
+    if (version.key && Number.isFinite(time) && time < (evidence.get(version.key) ?? Infinity)) evidence.set(version.key, time);
+  }
+  const { accepted, rejected, officialCount } = officialDates(await sources.releases(series.id, { pages, ...(maxAgeMs ? { maxAgeMs } : {}) }), run, evidence);
+  summary.official = officialCount; summary.rejected = rejected;
+  const have = new Set(versions.map(v => v.key));
+  summary.accepted = [...accepted.keys()].filter(key => have.has(key)).length;
+  for (const version of versions) {
+    const dates = version.meta['x-dates'] || { version: 1 }, next = accepted.get(version.key);
+    const prior = dates.release;
+    let changed = false;
+    if (next && JSON.stringify(prior) !== JSON.stringify(next)) { dates.release = next; changed = true; summary.written++; }
+    // A date this job wrote earlier and no longer accepts is withdrawn; other release dates stay.
+    else if (!next && prior && /^MangaUpdates\b/.test(prior.source || '') && pages === Infinity) { delete dates.release; changed = true; summary.cleared++; }
+    if (changed && apply) await writeJsonAtomic(version.file, { ...version.meta, 'x-dates': dates });
+  }
+  return summary;
+}
+
+module.exports = { ReleaseDateSources, officialDates, refreshMangaReleaseDates, chapterKey, isOfficial, EARLY_TOLERANCE_DAYS };