/**
 * Responsive preview tiers (#1095).
 *
 * A phone can display ~1170px at most, so the single 1920px preview ships
 * roughly twice the bytes it can use on every lightbox swipe — and the
 * lightbox prefetches neighbours, so a guest flicking through a wedding
 * gallery on cellular pays that repeatedly.
 *
 * The width is whitelisted rather than free-form: every distinct value is a
 * permanent cache entry on disk, so an open ?w= is an invitation to fill the
 * volume with renditions nobody asked for.
 */

const path = require('path');
const fs = require('fs');
const os = require('os');

process.env.NODE_ENV = 'test';
const tmpRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'picpeak-tiers-'));
process.env.TEST_DATABASE_PATH = path.join(tmpRoot, 'db.sqlite');
process.env.JWT_SECRET = process.env.JWT_SECRET || 'tiers-test-secret';
process.env.STORAGE_PATH = path.join(tmpRoot, 'storage');
fs.mkdirSync(process.env.STORAGE_PATH, { recursive: true });

const sharp = require('sharp');
const imageProcessor = require('../../src/services/imageProcessor');
const { bootCrmDb } = require('./helpers/crmDb');

let db; let cleanup;

describe('preview tiers (#1095)', () => {
  beforeAll(async () => {
    ({ db, cleanup } = await bootCrmDb());
  }, 120000);

  afterAll(async () => {
    if (cleanup) await cleanup();
    await fs.promises.rm(tmpRoot, { recursive: true, force: true }).catch(() => {});
  });

  describe('normalizeTierWidth', () => {
    const { normalizeTierWidth, PREVIEW_WIDTHS, THUMBNAIL_WIDTHS } = imageProcessor;

    it('accepts every advertised width', () => {
      for (const w of PREVIEW_WIDTHS) {
        expect(normalizeTierWidth(String(w), PREVIEW_WIDTHS)).toBe(w);
      }
      for (const w of THUMBNAIL_WIDTHS) {
        expect(normalizeTierWidth(String(w), THUMBNAIL_WIDTHS)).toBe(w);
      }
    });

    it('rejects anything not on the list', () => {
      // The disk-filling cases: arbitrary sizes, and a caller walking a range.
      for (const bad of ['999', '1921', '0', '-100', '99999']) {
        expect(normalizeTierWidth(bad, PREVIEW_WIDTHS)).toBeNull();
      }
    });

    it('rejects junk without throwing', () => {
      // Straight off a query string, so it is whatever the client sent.
      for (const bad of [undefined, null, '', 'abc', '12abc', {}, [], '1e3', 'NaN']) {
        expect(normalizeTierWidth(bad, PREVIEW_WIDTHS)).toBeNull();
      }
    });

    it('does not let a thumbnail width through the preview list', () => {
      // The two lists are separate on purpose; 600 is a thumb tier, not a
      // preview tier, and vice versa for 1280.
      expect(normalizeTierWidth('600', PREVIEW_WIDTHS)).toBeNull();
      expect(normalizeTierWidth('1280', THUMBNAIL_WIDTHS)).toBeNull();
    });
  });

  describe('ensurePreviewImageAtWidth', () => {
    async function seedPhoto() {
      const [e] = await db('events').insert({
        slug: `tier-${Math.random().toString(36).slice(2, 8)}`,
        event_type: 'wedding',
        event_name: 'tier',
        event_date: '2026-01-01',
        host_email: 'h@example.com',
        admin_email: 'a@example.com',
        password_hash: 'x',
        share_link: `tier-${Math.random()}`,
        expires_at: new Date().toISOString(),
      }).returning('id');
      const eventId = typeof e === 'object' ? e.id : e;

      // A real image on disk under STORAGE_PATH, since the managed branch
      // resolves through storage rather than a mount.
      const rel = `events/active/tier/${Math.random().toString(36).slice(2, 8)}.jpg`;
      const abs = path.join(process.env.STORAGE_PATH, rel);
      await fs.promises.mkdir(path.dirname(abs), { recursive: true });
      await sharp({ create: { width: 3000, height: 2000, channels: 3, background: { r: 10, g: 90, b: 160 } } })
        .jpeg().toFile(abs);

      const [p] = await db('photos').insert({
        event_id: eventId,
        filename: path.basename(rel),
        path: rel.replace(/^events\/active\//, ''),
        type: 'individual',
        width: 3000,
        height: 2000,
        processing_status: 'complete',
        source_origin: 'managed',
      }).returning('id');
      return db('photos').where({ id: typeof p === 'object' ? p.id : p }).first();
    }

    it('scopes keys by photo id so two galleries cannot collide', async () => {
      // The leak: managed auto-imports keep camera basenames, so two events can
      // each hold an IMG_0001.jpg. A tier is served straight from a cache hit
      // without re-reading the source, so a shared key hands one gallery's
      // photo to another.
      const a = await seedPhoto();
      const b = await seedPhoto();
      await db('photos').where({ id: a.id }).update({ path: 'wedding-a/IMG_0001.jpg' });
      await db('photos').where({ id: b.id }).update({ path: 'wedding-b/IMG_0001.jpg' });

      const keyA = imageProcessor.previewTierKeys(await db('photos').where({ id: a.id }).first())[0];
      const keyB = imageProcessor.previewTierKeys(await db('photos').where({ id: b.id }).first())[0];

      expect(keyA).not.toBe(keyB);
      expect(keyA).toContain(`p${a.id}_`);
      expect(keyB).toContain(`p${b.id}_`);
    });

    it('derives every non-default tier key for cleanup', () => {
      // Tiers live outside preview_path, so delete/archive/regenerate have no
      // other way to find them. 1920 is excluded because that IS preview_path.
      // Two candidates per width — the encoder picks `.jpg` or `.webp` and the
      // cleanup list cannot know which without probing the source.
      const keys = imageProcessor.previewTierKeys({ id: 5, path: 'e/a.jpg', source_origin: 'managed' });
      const widths = imageProcessor.PREVIEW_WIDTHS.filter((w) => w !== 1920);
      expect(keys).toHaveLength(widths.length * 2);
      for (const w of widths) {
        expect(keys).toContain(`previews/preview_w${w}_p5_a.jpg`);
        expect(keys).toContain(`previews/preview_w${w}_p5_a.webp`);
      }
      expect(keys.some((k) => k.includes('w1920'))).toBe(false);
      expect(keys.every((k) => k.includes('p5_'))).toBe(true);
    });

    it('deletePreviewTiers removes generated tiers from storage', async () => {
      const photo = await seedPhoto();
      const key = await imageProcessor.ensurePreviewImageAtWidth(photo, 640);
      const abs = path.join(process.env.STORAGE_PATH, key);
      expect(fs.existsSync(abs)).toBe(true);

      await imageProcessor.deletePreviewTiers(await db('photos').where({ id: photo.id }).first());
      expect(fs.existsSync(abs)).toBe(false);
    });

    it('produces a distinct key per width and never touches preview_path', async () => {
      const photo = await seedPhoto();

      const small = await imageProcessor.ensurePreviewImageAtWidth(photo, 640);
      expect(small).toContain('preview_w640_');

      // The extra tiers are cache, not state. Writing them to the row would
      // mean the last size requested silently becomes "the" preview.
      const row = await db('photos').where({ id: photo.id }).first();
      expect(row.preview_path == null || !String(row.preview_path).includes('w640')).toBe(true);
    });

    it('resolves the default width to the canonical preview, not a w1920 copy', async () => {
      // Otherwise every existing install grows a duplicate of every preview it
      // already has, for no benefit.
      const photo = await seedPhoto();
      const def = await imageProcessor.ensurePreviewImageAtWidth(photo, 1920);
      expect(def).not.toContain('preview_w1920_');
    });

    it('reuses the cached tier instead of regenerating', async () => {
      const photo = await seedPhoto();
      const first = await imageProcessor.ensurePreviewImageAtWidth(photo, 1280);
      expect(first).toBeTruthy();

      const abs = path.join(process.env.STORAGE_PATH, first);
      const before = (await fs.promises.stat(abs)).mtimeMs;
      await new Promise((r) => setTimeout(r, 20));

      const second = await imageProcessor.ensurePreviewImageAtWidth(photo, 1280);
      expect(second).toBe(first);
      expect((await fs.promises.stat(abs)).mtimeMs).toBe(before);
    });

    it('actually resizes to the requested tier', async () => {
      const photo = await seedPhoto();
      const key = await imageProcessor.ensurePreviewImageAtWidth(photo, 640);
      const meta = await sharp(path.join(process.env.STORAGE_PATH, key)).metadata();
      // 3000x2000 constrained to a 640 long edge.
      expect(Math.max(meta.width, meta.height)).toBe(640);
      expect(meta.height).toBe(Math.round(640 * (2000 / 3000)));
    });
  });

  describe('thumbnail tiers', () => {
    async function seedThumbPhoto(w = 3000, h = 2000) {
      const [e] = await db('events').insert({
        slug: `tt-${Math.random().toString(36).slice(2, 8)}`,
        event_type: 'wedding', event_name: 'tt', event_date: '2026-01-01',
        host_email: 'h@example.com', admin_email: 'a@example.com',
        password_hash: 'x', share_link: `tt-${Math.random()}`,
        expires_at: new Date().toISOString(),
      }).returning('id');
      const eventId = typeof e === 'object' ? e.id : e;
      const rel = `events/active/tt/${Math.random().toString(36).slice(2, 8)}.jpg`;
      const abs = path.join(process.env.STORAGE_PATH, rel);
      await fs.promises.mkdir(path.dirname(abs), { recursive: true });
      await sharp({ create: { width: w, height: h, channels: 3, background: { r: 5, g: 5, b: 5 } } })
        .jpeg().toFile(abs);
      const [p2] = await db('photos').insert({
        event_id: eventId, filename: path.basename(rel),
        path: rel.replace(/^events\/active\//, ''), type: 'individual',
        width: w, height: h, processing_status: 'complete', source_origin: 'managed',
      }).returning('id');
      return db('photos').where({ id: typeof p2 === 'object' ? p2.id : p2 }).first();
    }

    it('scopes thumbnail tier keys by photo id', async () => {
      // Same cross-gallery hazard the preview tiers had: a cache hit serves
      // without re-reading the source, so a shared basename leaks across events.
      const keys = imageProcessor.thumbnailTierKeys({ id: 42, path: 'a/IMG_0001.jpg', source_origin: 'managed' });
      expect(keys.every((k) => k.includes('p42_'))).toBe(true);
      // Every width, canonical included: which one is canonical depends on the
      // thumbnail_width setting, so on a 600-configured install w300 is the
      // tier file. Deleting a key that was never written is a no-op; missing
      // one strands it forever.
      expect(keys).toHaveLength(3);
    });

    it('tags the tier against the configured width, not the 300 default', async () => {
      // Regression: with thumbnail_width=600 a w=300 request wrote
      // `thumb_<name>` while the caller probed `thumb_w300_<name>`. The cache
      // never hit, so every request re-downloaded the original and ran Sharp,
      // and the file it left behind was in no cleanup list.
      await db('app_settings').where('setting_key', 'thumbnail_width')
        .update({ setting_value: 600 });
      try {
        const photo = await seedThumbPhoto();

        const first = await imageProcessor.ensureThumbnailAtWidth(photo, 300);
        expect(first).toContain('thumb_w300_');

        // The second call must be a cache hit on the key the first one wrote.
        const before = fs.statSync(path.join(process.env.STORAGE_PATH, first)).mtimeMs;
        const second = await imageProcessor.ensureThumbnailAtWidth(photo, 300);
        expect(second).toBe(first);
        expect(fs.statSync(path.join(process.env.STORAGE_PATH, second)).mtimeMs).toBe(before);

        // ...and 600 is now the canonical, so it resolves to the plain thumbnail.
        const canonical = await imageProcessor.ensureThumbnailAtWidth(photo, 600);
        expect(canonical).not.toContain('thumb_w600_');

        // Cleanup still reaches the w300 tier this install actually generated.
        expect(imageProcessor.thumbnailTierKeys(photo)).toContain(first);
      } finally {
        await db('app_settings').where('setting_key', 'thumbnail_width')
          .update({ setting_value: 300 });
      }
    });

    it('generates a tier at the requested size', async () => {
      const photo = await seedThumbPhoto();
      const key = await imageProcessor.ensureThumbnailAtWidth(photo, 600);
      expect(key).toContain('thumb_w600_');
      const meta = await sharp(path.join(process.env.STORAGE_PATH, key)).metadata();
      expect(Math.max(meta.width, meta.height)).toBe(600);
    });

    it('does not upscale past the source, which is why the tier is clamped', async () => {
      // The reason tileThumbnailWidth checks the short edge: ask a 400px
      // source for 900 and withoutEnlargement caps it, so the request buys a
      // Sharp run and a second cache entry for a file identical to the 300.
      const small = await seedThumbPhoto(500, 400);
      const key = await imageProcessor.ensureThumbnailAtWidth(small, 900);
      const meta = await sharp(path.join(process.env.STORAGE_PATH, key)).metadata();
      expect(Math.max(meta.width, meta.height)).toBeLessThan(900);
    });

    it('resolves the canonical width to the normal thumbnail', async () => {
      const photo = await seedThumbPhoto();
      const key = await imageProcessor.ensureThumbnailAtWidth(photo, 300);
      expect(key).not.toContain('thumb_w300_');
    });

    it('keeps the configured aspect ratio instead of forcing a square', async () => {
      // Thumbnails are square by default, but the settings API takes any
      // width/height in 50..1000. With fit:'cover' a 300x200 canonical and a
      // 600x600 tier are two different crops, so the photo would visibly
      // reframe as the tile size changed.
      await db('app_settings').where('setting_key', 'thumbnail_height')
        .update({ setting_value: 200 });
      try {
        const photo = await seedThumbPhoto();
        const key = await imageProcessor.ensureThumbnailAtWidth(photo, 600);
        const meta = await sharp(path.join(process.env.STORAGE_PATH, key)).metadata();
        expect(meta.width).toBe(600);
        expect(meta.height).toBe(400); // 600 * (200/300), not 600
      } finally {
        await db('app_settings').where('setting_key', 'thumbnail_height')
          .update({ setting_value: 300 });
      }
    });

    it('never hands a video to Sharp', async () => {
      // A video's thumbnail is a poster frame from videoProcessor, not a
      // resize of the stored file. Without the short-circuit the tier path
      // would download the whole video (withLocalCopy, in full on S3) and
      // then fail to decode it — every request, since nothing caches a miss.
      const photo = await seedThumbPhoto();
      await db('photos').where({ id: photo.id })
        .update({ media_type: 'video', mime_type: 'video/mp4' });
      const video = await db('photos').where({ id: photo.id }).first();

      const key = await imageProcessor.ensureThumbnailAtWidth(video, 900);
      expect(key).not.toContain('thumb_w900_');
    });

    it('drops tiers when a rename moves the basename they are keyed on', async () => {
      // The key embeds the basename, so the DB update in renamePhotoFiles is
      // the point past which the old keys cannot be derived at all — a later
      // delete or archive computes the new ones and leaves these behind.
      const renameService = require('../../src/services/eventRenameService');
      const photo = await seedThumbPhoto();
      const event = await db('events').where({ id: photo.event_id }).first();

      // Give it a filename the rename will actually rewrite.
      const dir = path.join(process.env.STORAGE_PATH, 'events/active', event.slug, 'individual');
      await fs.promises.mkdir(dir, { recursive: true });
      await sharp({ create: { width: 1200, height: 900, channels: 3, background: { r: 7, g: 7, b: 7 } } })
        .jpeg().toFile(path.join(dir, 'Old_Name_001.jpg'));
      await db('photos').where({ id: photo.id }).update({
        filename: 'Old_Name_001.jpg',
        path: `${event.slug}/individual/Old_Name_001.jpg`,
      });
      const renamable = await db('photos').where({ id: photo.id }).first();

      const key = await imageProcessor.ensureThumbnailAtWidth(renamable, 600);
      const abs = path.join(process.env.STORAGE_PATH, key);
      expect(fs.existsSync(abs)).toBe(true);

      await renameService.renamePhotoFiles(
        event.id, 'Old Name', 'New Name', event.slug, event.slug
      );

      expect(await db('photos').where({ id: photo.id }).first())
        .toMatchObject({ filename: 'New_Name_001.jpg' });
      expect(fs.existsSync(abs)).toBe(false);
    });

    it('leaves tiers alone when a rename does not move the basename', async () => {
      // Four storage deletes per photo is 20k calls against S3 for a
      // 5,000-photo event whose slug merely changed, so the sweep is gated on
      // the filename actually moving.
      const renameService = require('../../src/services/eventRenameService');
      const photo = await seedThumbPhoto();
      const event = await db('events').where({ id: photo.event_id }).first();

      const key = await imageProcessor.ensureThumbnailAtWidth(photo, 600);
      const abs = path.join(process.env.STORAGE_PATH, key);

      // The photo's filename carries no event-name prefix, so nothing moves.
      await renameService.renamePhotoFiles(
        event.id, 'Old Name', 'New Name', event.slug, event.slug
      );

      expect(fs.existsSync(abs)).toBe(true);
    });

    it('deleteThumbnailTiers removes them', async () => {
      const photo = await seedThumbPhoto();
      const key = await imageProcessor.ensureThumbnailAtWidth(photo, 600);
      const abs = path.join(process.env.STORAGE_PATH, key);
      expect(fs.existsSync(abs)).toBe(true);
      await imageProcessor.deleteThumbnailTiers(await db('photos').where({ id: photo.id }).first());
      expect(fs.existsSync(abs)).toBe(false);
    });

    /**
     * The crash in #1128 needed two things: a tier that disappears, and a
     * reader that dies on it. The reader is fixed in streamResponse; this is
     * the half that stops the file disappearing in the first place.
     */
    describe('concurrent generation (#1128)', () => {
      it('never leaves the tier absent once it has been published', async () => {
        const photo = await seedThumbPhoto();
        const key = imageProcessor.thumbnailTierKeys(photo).find((k) => k.includes('_w600_'));
        const abs = path.join(process.env.STORAGE_PATH, key);

        // A grid fires one request per tile at once, and on a cold gallery
        // every one of them misses the cache. Previously each carried
        // `regenerate: true`, whose first act is to DELETE the target — so a
        // later arrival unlinked the file an earlier one had already published
        // and handed to a reader.
        const watcher = [];
        const poll = setInterval(() => watcher.push(fs.existsSync(abs)), 1);

        const results = await Promise.all(
          Array.from({ length: 12 }, () => imageProcessor.ensureThumbnailAtWidth(photo, 600))
        );
        clearInterval(poll);

        expect(results.every((r) => r === key)).toBe(true);
        expect(fs.existsSync(abs)).toBe(true);

        // Once true, never false again: no window where a validated file is gone.
        const firstSeen = watcher.indexOf(true);
        if (firstSeen !== -1) {
          expect(watcher.slice(firstSeen).every(Boolean)).toBe(true);
        }
      });

      it('runs one generation for a burst of requests, not one per request', async () => {
        const photo = await seedThumbPhoto();
        const thumbDir = path.join(process.env.STORAGE_PATH, 'thumbnails');
        await fs.promises.mkdir(thumbDir, { recursive: true });

        // Counted through the staging files LocalFsStorage writes:
        // `<key>.tmp.<pid>.<hex>`, one per put, each a distinct random suffix.
        // So distinct temp names == distinct generations, which is the thing
        // the dedupe is supposed to collapse. (Spying on generateThumbnail
        // would not work — ensureThumbnailAtWidth calls it through the
        // module-local binding, so an export spy never sees it.)
        const seen = new Set();
        const poll = setInterval(() => {
          for (const f of fs.readdirSync(thumbDir)) {
            if (f.includes('_w900_') && f.includes('.tmp.')) seen.add(f);
          }
        }, 1);

        const results = await Promise.all(
          Array.from({ length: 8 }, () => imageProcessor.ensureThumbnailAtWidth(photo, 900))
        );
        clearInterval(poll);

        const abs = path.join(
          process.env.STORAGE_PATH,
          imageProcessor.thumbnailTierKeys(photo).find((k) => k.includes('_w900_'))
        );
        expect(fs.existsSync(abs)).toBe(true);
        expect(new Set(results).size).toBe(1);
        // 8 requests, at most one Sharp pass. Before the dedupe this was 8 —
        // and on an external photo, 8 full reads of the original.
        expect(seen.size).toBeLessThanOrEqual(1);
      });

      it('does not cache a failure — a later request retries', async () => {
        const photo = await seedThumbPhoto();
        // Source removed underneath: generation fails and must not poison the
        // key for the lifetime of the process.
        const src = path.join(process.env.STORAGE_PATH, 'events/active', photo.path);
        const saved = await fs.promises.readFile(src);
        await fs.promises.unlink(src);

        expect(await imageProcessor.ensureThumbnailAtWidth(photo, 600)).toBeNull();

        await fs.promises.writeFile(src, saved);
        expect(await imageProcessor.ensureThumbnailAtWidth(photo, 600)).toContain('_w600_');
      });
    });
  });
});