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

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

const sampleGold = [
  JSON.stringify({
    question: 'What is the meaning of life?',
    sample: { answer: '42', raw: '42' },
    context: [{ id: 'c1', content: 'ctx content' }],
    verifier: { ok: true, score: 0.9 },
    reward: { score: 0.8 },
  }),
  JSON.stringify({
    question: 'Q1?',
    sample: { answer: 'a'.repeat(50) },
    context: [{ id: 'c2', content: 'ctx content 2' }],
  }),
].join('\n');

describe('scripts/gold_preview.mjs', () => {
  let tmpFile;
  const origArgv = process.argv.slice();

  beforeEach(async () => {
    const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'gold-prev-'));
    tmpFile = path.join(tmpDir, 'gold.jsonl');
    await fs.writeFile(tmpFile, sampleGold, 'utf8');
  });

  afterEach(async () => {
    process.argv = origArgv.slice();
    if (tmpFile) {
      await fs.rm(path.dirname(tmpFile), { recursive: true, force: true }).catch(() => {});
    }
  });

  it('respects --limit', async () => {
    process.argv = ['node', 'gold_preview.mjs', '--file', tmpFile, '--limit', '1'];
    const { capturePreview } = await import('../scripts/gold_preview.mjs');
    const output = await capturePreview();
    const lines = output.split('\n').filter(Boolean);
    expect(lines.some((l) => l.startsWith('#2'))).toBe(false);
  });

  it('respects --max-answer truncation', async () => {
    process.argv = ['node', 'gold_preview.mjs', '--file', tmpFile, '--max-answer', '10'];
    const { capturePreview } = await import('../scripts/gold_preview.mjs');
    const output = await capturePreview();
    expect(output).toMatch(/A: a{10}… \[\+40 chars\]/);
  });

  it('shows full when --full is set', async () => {
    process.argv = ['node', 'gold_preview.mjs', '--file', tmpFile, '--full', '--limit', '1'];
    const { capturePreview } = await import('../scripts/gold_preview.mjs');
    const output = await capturePreview();
    expect(output).toMatch(/A: 42/);
    expect(output).not.toMatch(/\[\+\d+ chars\]/);
  });
});