#!/usr/bin/env node
import { promises as fs } from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { run as runReadFile } from '../tools/read_file.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const chrootRoot = '/home/seb/src/aiTools/tmp';
const sandboxRoot = path.resolve(chrootRoot, 'readfile-tests');

async function rimraf(dir) {
  await fs.rm(dir, { recursive: true, force: true });
}

async function ensureDir(dir) {
  await fs.mkdir(dir, { recursive: true });
}

async function writeFiles(baseDir, filesMap) {
  for (const [rel, content] of Object.entries(filesMap || {})) {
    const filePath = path.resolve(baseDir, rel);
    await ensureDir(path.dirname(filePath));
    await fs.writeFile(filePath, content, 'utf8');
  }
}

function slugify(name) {
  return name.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/(^-|-$)/g, '');
}

function expectEqual(actual, expected, label) {
  if (actual !== expected) {
    const ellipsize = (s) => (s && s.length > 400 ? s.slice(0, 400) + '…' : (s ?? '<<undefined>>'));
    throw new Error(`${label} mismatch.\nExpected:\n${ellipsize(expected)}\nActual:\n${ellipsize(actual)}`);
  }
}

function expectRegex(actual, re, label) {
  if (!re.test(actual)) {
    throw new Error(`${label} mismatch. Expected to match ${re}, Actual: ${actual}`);
  }
}

async function runCase(index, testCase) {
  const idx = String(index + 1).padStart(2, '0');
  const caseDir = path.resolve(sandboxRoot, `${idx}-${slugify(testCase.name)}`);
  await ensureDir(chrootRoot);
  await rimraf(caseDir);
  await ensureDir(caseDir);

  await writeFiles(caseDir, typeof testCase.before === 'function' ? await testCase.before({ dir: caseDir }) : (testCase.before || {}));

  const args = await testCase.args({ dir: caseDir });
  const result = await runReadFile(args);
  if (testCase.expect?.equals !== undefined) {
    expectEqual(result, testCase.expect.equals, 'Tool result');
  }
  if (testCase.expect?.errorRegex) {
    expectRegex(result, testCase.expect.errorRegex, 'Error');
  }
}

function cases() {
  const list = [];

  // 1. Read entire small file
  list.push({
    name: 'read entire file',
    before: { 'a.txt': 'A\nB\nC' },
    args: async ({ dir }) => ({ path: path.relative(chrootRoot, path.join(dir, 'a.txt')), linesToSkip: 0, linesToRead: 400 }),
    expect: { equals: 'A\nB\nC' }
  });

  // 2. Skip first line, read next 1
  list.push({
    name: 'skip and read one',
    before: { 'a.txt': 'A\nB\nC' },
    args: async ({ dir }) => ({ path: path.relative(chrootRoot, path.join(dir, 'a.txt')), linesToSkip: 1, linesToRead: 1 }),
    expect: { equals: 'B' }
  });

  // 3. linesToRead 0 defaults to 400
  list.push({
    name: 'linesToRead zero defaults',
    before: { 'a.txt': 'L1\nL2\nL3' },
    args: async ({ dir }) => ({ path: path.relative(chrootRoot, path.join(dir, 'a.txt')), linesToSkip: 0, linesToRead: 0 }),
    expect: { equals: 'L1\nL2\nL3' }
  });

  // 4. Missing file -> error string
  list.push({
    name: 'missing file error',
    before: {},
    args: async ({ dir }) => ({ path: path.relative(chrootRoot, path.join(dir, 'nope.txt')), linesToSkip: 0, linesToRead: 100 }),
    expect: { errorRegex: /read_file error:/ }
  });

  // 5. Path outside chroot -> error
  list.push({
    name: 'path outside chroot error',
    before: {},
    args: async () => ({ path: '../../etc/passwd', linesToSkip: 0, linesToRead: 100 }),
    expect: { errorRegex: /read_file error: Path outside of allowed directory/ }
  });

  // 6. Large file truncated to 400 lines
  list.push({
    name: 'truncate to 400 lines',
    before: async () => {
      const many = Array.from({ length: 450 }, (_, i) => `L${i + 1}`).join('\n');
      return { 'big.txt': many };
    },
    args: async ({ dir }) => ({ path: path.relative(chrootRoot, path.join(dir, 'big.txt')), linesToSkip: 0, linesToRead: 99999 }),
    expect: { equals: Array.from({ length: 400 }, (_, i) => `L${i + 1}`).join('\n') }
  });

  return list;
}

async function main() {
  const all = cases();
  await ensureDir(sandboxRoot);
  let passed = 0;
  let failed = 0;

  for (let i = 0; i < all.length; i++) {
    const tc = all[i];
    const label = `${String(i + 1).padStart(2, '0')} ${tc.name}`;
    try {
      await runCase(i, tc);
      console.log(`✓ ${label}`);
      passed++;
    } catch (err) {
      console.error(`✗ ${label}`);
      console.error(String(err?.stack || err));
      failed++;
    }
  }

  console.log('');
  console.log(`Passed: ${passed}, Failed: ${failed}, Total: ${all.length}`);
  if (failed > 0) process.exit(1);
}

main().catch((err) => {
  console.error('Fatal error in read_file test runner:', err);
  process.exit(1);
});