import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import fs from 'fs/promises';
import path from 'path';
import os from 'os';
import { fileURLToPath, pathToFileURL } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const PROJECT_ROOT = path.join(__dirname, '..');

describe('scripts/regenerate_gold_from_cache.mjs', () => {
  let tmpDir;
  let cacheDir;
  let goldPath;
  let ragPath;
  const origEnv = { ...process.env };

  beforeEach(async () => {
    tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'regen-cache-'));
    cacheDir = path.join(tmpDir, 'cache');
    goldPath = path.join(tmpDir, 'pipeline_gold.jsonl');
    ragPath = path.join(tmpDir, 'rag_chunks.jsonl');

    process.env.PIPELINE_CACHE_DIR = cacheDir;
    process.env.GOLD_PATH = goldPath;
    process.env.RAG_CHUNKS_PATH = ragPath;

    await fs.mkdir(cacheDir, { recursive: true });
    await fs.mkdir(path.dirname(goldPath), { recursive: true });
    await fs.mkdir(path.dirname(ragPath), { recursive: true });
  });

  afterEach(async () => {
    process.env = { ...origEnv };
    await fs.rm(tmpDir, { recursive: true, force: true }).catch(() => {});
  });

  it('reconstructs gold from cache with reward/verifier ok', async () => {
    // write chunks
    const chunk = { id: 'c1', content: 'chunk content', source: { meta: 1 } };
    await fs.writeFile(ragPath, JSON.stringify(chunk) + '\n', 'utf8');

    // questions cache
    await fs.writeFile(
      path.join(cacheDir, 'questions.jsonl'),
      JSON.stringify({
        chunk_id: 'c1',
        questions: ['What is X?'],
        question_ids: ['q1'],
        ts: Date.now(),
      }) + '\n',
      'utf8',
    );

    // generations cache
    await fs.writeFile(
      path.join(cacheDir, 'generations.jsonl'),
      JSON.stringify({
        chunk_id: 'c1',
        question_id: 'q1',
        gen_id: 'g1',
        answer: 'Answer text',
        raw: 'Answer text',
        ts: Date.now(),
      }) + '\n',
      'utf8',
    );

    // verification cache (ok)
    await fs.writeFile(
      path.join(cacheDir, 'verifications.jsonl'),
      JSON.stringify({
        chunk_id: 'c1',
        question_id: 'q1',
        gen_id: 'g1',
        ok: true,
        score: 'PASS',
        raw: '...',
        ts: Date.now(),
      }) + '\n',
      'utf8',
    );

    // reward cache (ok)
    await fs.writeFile(
      path.join(cacheDir, 'rewards.jsonl'),
      JSON.stringify({
        chunk_id: 'c1',
        question_id: 'q1',
        gen_id: 'g1',
        ok: true,
        score: 0.9,
        raw: '0.9',
        ts: Date.now(),
      }) + '\n',
      'utf8',
    );

    const mod = await import(pathToFileURL(path.join(PROJECT_ROOT, 'scripts', 'regenerate_gold_from_cache.mjs')));
    await mod.main();

    const out = await fs.readFile(goldPath, 'utf8');
    const lines = out.split('\n').filter(Boolean);
    expect(lines).toHaveLength(1);

    const rec = JSON.parse(lines[0]);
    expect(rec.question).toBe('What is X?');
    expect(rec.sample.answer).toBe('Answer text');
    expect(rec.verifier.ok).toBe(true);
    expect(rec.reward.score).toBe(0.9);
  });
});