import { afterAll, beforeAll, describe, expect, test } from 'vitest';
import { promises as fs } from 'fs';
import os from 'os';
import path from 'path';
import {
  clearKnowledgeCache,
  loadCoursewareKnowledge,
  retrieveChunks,
  tokenizeQuery,
} from '@/lib/qa/knowledge';
import { createFileBundleByteStore } from '@/lib/courseware-repo/bundle-store';
import { packageSampleBundle } from '../bundle/fixtures';

describe('tokenizeQuery', () => {
  test('extracts CJK bigrams and ascii words', () => {
    const terms = tokenizeQuery('叶绿体 光合作用 how do plants work');
    expect(terms).toContain('叶绿');
    expect(terms).toContain('绿体');
    expect(terms).toContain('光合');
    expect(terms).toContain('plants');
    expect(terms).toContain('work');
  });

  test('returns nothing for noise', () => {
    expect(tokenizeQuery('?!?!')).toEqual([]);
    expect(tokenizeQuery('a b')).toEqual([]); // single chars filtered
  });
});

describe('retrieveChunks', () => {
  const knowledge = {
    coursewareId: 'cw-1',
    language: 'zh-CN',
    scenes: [
      {
        sceneId: 's1',
        order: 1,
        title: '光合作用概述',
        type: 'slide' as const,
        text: '叶绿体是光合作用的场所。光反应与暗反应。',
        narration: '今天我们来学习光合作用。',
      },
      {
        sceneId: 's2',
        order: 2,
        title: '细胞呼吸',
        type: 'slide' as const,
        text: '线粒体是有氧呼吸的主要场所。',
      },
      {
        sceneId: 's3',
        order: 3,
        title: '小测验',
        type: 'quiz' as const,
        text: '问：光合作用发生在细胞的哪个结构？',
      },
    ],
  };

  test('scores title matches above body matches', () => {
    const hits = retrieveChunks(knowledge, '光合作用 发生在哪里', 2);
    expect(hits.length).toBeGreaterThan(0);
    // Title match (s1: "光合作用概述" + s3 title "小测验"? s3 text has 光合作用) —
    // s1 must rank first on combined score.
    expect(hits[0].sceneId).toBe('s1');
  });

  test('respects the limit and drops non-matching scenes', () => {
    const hits = retrieveChunks(knowledge, '线粒体 有氧呼吸', 1);
    expect(hits).toHaveLength(1);
    expect(hits[0].sceneId).toBe('s2');
  });

  test('empty query returns nothing', () => {
    expect(retrieveChunks(knowledge, '啊 呢')).toEqual([]);
  });
});

describe('loadCoursewareKnowledge', () => {
  let bytesDir: string;
  beforeAll(async () => {
    bytesDir = await fs.mkdtemp(path.join(os.tmpdir(), 'qa-knowledge-'));
    const packaged = await packageSampleBundle({ coursewareId: 'kw-1' });
    const store = createFileBundleByteStore(bytesDir);
    await store.save(
      'kw-1',
      1,
      new Uint8Array(await packaged.zip.arrayBuffer()),
    );
  });
  afterAll(async () => {
    await fs.rm(bytesDir, { recursive: true, force: true });
    clearKnowledgeCache();
  });

  test('loads knowledge and quiz packs from the frozen bundle', async () => {
    const store = createFileBundleByteStore(bytesDir);
    const knowledge = await loadCoursewareKnowledge('kw-1', 1, store);
    expect(knowledge).not.toBeNull();
    expect(knowledge!.title).toBe('示例课件：光合作用');
    expect(knowledge!.language).toBe('zh-CN');
    expect(knowledge!.knowledge.scenes).toHaveLength(3);
    expect(knowledge!.quiz.scenes).toHaveLength(1);
    expect(knowledge!.knowledge.scenes[0].narration).toContain('光合作用');
  });

  test('returns null for an unknown version', async () => {
    expect(await loadCoursewareKnowledge('kw-1', 99)).toBeNull();
  });
});