import assert from 'node:assert/strict';
import test from 'node:test';
import { createPlazaEventService } from './plaza-events.mjs';
import { recommendInternals } from './plaza-recommend.mjs';

test('plaza events: dwell tiers increase signal weight', () => {
  const { eventSignal } = createPlazaEventService({ query: async () => [[]] }).internals;
  const short = eventSignal({ event_type: 'dwell', dwell_ms: 1000 });
  const medium = eventSignal({ event_type: 'dwell', dwell_ms: 5000 });
  const long = eventSignal({ event_type: 'dwell', dwell_ms: 35000 });
  assert.ok(medium > short);
  assert.ok(long > medium);
});

test('plaza recommend: mmr rerank reduces same-category clustering', () => {
  const { mmrRerank, itemSimilarity } = recommendInternals;
  const items = [
    {
      id: 'a',
      rank_score: 0.95,
      category_slug: 'travel',
      author_id: 'u1',
      tags: ['日本'],
    },
    {
      id: 'b',
      rank_score: 0.93,
      category_slug: 'travel',
      author_id: 'u2',
      tags: ['日本'],
    },
    {
      id: 'c',
      rank_score: 0.9,
      category_slug: 'study-notes',
      author_id: 'u3',
      tags: ['rust'],
    },
  ];
  const reranked = mmrRerank(items, { lambda: 0.75, limit: 3 });
  assert.equal(reranked[0].id, 'a');
  assert.notEqual(reranked[1].category_slug, reranked[0].category_slug);
  assert.equal(itemSimilarity(items[0], items[1]), 1);
});

test('plaza recommend: cursor roundtrip preserves offset', () => {
  const { parseRecommendCursor, encodeRecommendCursor } = recommendInternals;
  const encoded = encodeRecommendCursor({ offset: 20, profileVersion: 42 });
  const parsed = parseRecommendCursor(encoded);
  assert.equal(parsed.offset, 20);
  assert.equal(parsed.profileVersion, 42);
});

test('plaza recommend: cold start interleaves categories', () => {
  const { coldStartInterleave } = recommendInternals;
  const items = [
    { id: 'a1', category_slug: 'travel', hot_score: 90, published_at: 1 },
    { id: 'a2', category_slug: 'travel', hot_score: 80, published_at: 2 },
    { id: 'b1', category_slug: 'study-notes', hot_score: 85, published_at: 3 },
    { id: 'c1', category_slug: 'creative', hot_score: 70, published_at: 4 },
  ];
  const ordered = coldStartInterleave(items, 'session-1');
  assert.equal(ordered.length, 4);
  assert.notEqual(ordered[0].category_slug, ordered[1].category_slug);
});

test('plaza events: dislike marks category as disliked', () => {
  const { emptyProfile } = createPlazaEventService({ query: async () => [[]] }).internals;
  const profile = emptyProfile();
  profile.dislikedCategorySlugs.add('travel');
  profile.dislikedPostIds.add('post-1');
  assert.ok(profile.dislikedCategorySlugs.has('travel'));
  assert.ok(profile.deepSeenPostIds instanceof Set);
});
