import assert from 'node:assert/strict';
import test from 'node:test';
import {
  applyRecallFusionToMemoryMerge,
  fuseRecallCandidates,
  normalizeRecallCandidate,
  reciprocalRankFusion,
  resolveRecallFusionMode,
} from './recall-fusion.mjs';

test('resolveRecallFusionMode defaults to off', () => {
  assert.equal(resolveRecallFusionMode({}), 'off');
  assert.equal(resolveRecallFusionMode({ MEMIND_RECALL_FUSION_MODE: 'shadow' }), 'shadow');
});

test('reciprocalRankFusion boosts items appearing in multiple lists', () => {
  const shared = normalizeRecallCandidate(
    { id: 'm1', text: '用户偏好简洁回答' },
    { source: 'personal', rank: 0, query: '偏好' },
  );
  const episodicOnly = normalizeRecallCandidate(
    { id: 'm2', text: '上次讨论了苏州旅行' },
    { source: 'episodic', rank: 0, query: '苏州' },
  );
  const fused = reciprocalRankFusion([
    { source: 'personal', candidates: [shared] },
    { source: 'episodic', candidates: [shared, episodicOnly] },
  ], { k: 60 });
  assert.equal(fused[0].id, 'm1');
  assert.ok(fused[0].sources.includes('personal'));
  assert.ok(fused[0].sources.includes('episodic'));
});

test('fuseRecallCandidates dedupes duplicate fingerprints across sources', () => {
  const duplicate = '用户喜欢咖啡';
  const fusion = fuseRecallCandidates({
    query: '咖啡偏好',
    personalMemories: [{ id: 'p1', text: duplicate }],
    episodicMemories: [{ id: 'e1', text: duplicate }],
    limit: 3,
    env: { MEMIND_RECALL_FUSION_MODE: 'active' },
  });
  assert.equal(fusion.keptCount, 1);
  assert.equal(fusion.duplicateCount, 1);
});

test('applyRecallFusionToMemoryMerge keeps legacy merge in shadow mode', () => {
  const applied = applyRecallFusionToMemoryMerge({
    personalMemories: [{ id: 'p1', text: 'alpha' }],
    episodicMemories: [{ id: 'e1', text: 'beta' }],
    query: 'alpha',
    limit: 1,
    legacyMerge: () => [{ id: 'legacy', text: 'legacy-only' }],
    env: { MEMIND_RECALL_FUSION_MODE: 'shadow' },
  });
  assert.equal(applied.applied, false);
  assert.equal(applied.memories[0].id, 'legacy');
  assert.ok(applied.fusion);
});

test('applyRecallFusionToMemoryMerge uses fused ranking in active mode', () => {
  const duplicate = '共享记忆';
  const applied = applyRecallFusionToMemoryMerge({
    personalMemories: [{ id: 'p1', text: duplicate }],
    episodicMemories: [{ id: 'e1', text: duplicate }, { id: 'e2', text: 'unique episodic' }],
    query: '共享',
    limit: 2,
    legacyMerge: () => [{ id: 'legacy', text: 'legacy-only' }],
    env: { MEMIND_RECALL_FUSION_MODE: 'active' },
  });
  assert.equal(applied.applied, true);
  assert.equal(applied.memories.length, 2);
  assert.notEqual(applied.memories[0].id, 'legacy');
});