import assert from 'node:assert/strict';
import { chmod, mkdir, rm, symlink, utimes, writeFile } from 'node:fs/promises';
import path from 'node:path';
import test from 'node:test';

import { runPreflight, sourceFingerprint } from './preflight.mjs';

const fixtureRoot = path.join(process.cwd(), '.mosaic-test-work', `preflight-${process.pid}`);

const requiredBins = ['eslint', 'husky', 'prettier', 'tsc', 'turbo', 'vitest'];

async function fixture(name) {
  const root = path.join(fixtureRoot, name);
  await mkdir(path.join(root, 'apps', 'web', 'src', 'app'), { recursive: true });
  await writeFile(path.join(root, 'apps', 'web', 'src', 'app', 'page.tsx'), 'export default 1;\n');
  return root;
}

async function installRequiredBins(root) {
  const binDir = path.join(root, 'node_modules', '.bin');
  await mkdir(binDir, { recursive: true });
  await Promise.all(
    requiredBins.map(async (name) => {
      const target = path.join(binDir, name);
      await writeFile(target, '');
      await chmod(target, 0o755);
    }),
  );
}

test.after(async () => {
  await rm(fixtureRoot, { recursive: true, force: true });
});

test('missing dependencies have a dedicated exit code and install remediation', async () => {
  const root = await fixture('missing-deps');
  const result = await runPreflight({ root });

  assert.equal(result.code, 42);
  assert.match(result.message, /MOSAIC_PREFLIGHT_MISSING_DEPS/);
  assert.match(result.message, /run pnpm install/i);
});

test('a partial dependency install keeps the dedicated missing-deps result', async () => {
  const root = await fixture('partial-deps');
  await mkdir(path.join(root, 'node_modules', '.bin'), { recursive: true });
  await writeFile(path.join(root, 'node_modules', '.bin', 'tsc'), '', { mode: 0o755 });

  const result = await runPreflight({ root });
  assert.equal(result.code, 42);
  assert.match(result.message, /turbo/);
});

test('a dangling required dependency shim keeps the dedicated missing-deps result', async () => {
  const root = await fixture('dangling-deps');
  await installRequiredBins(root);
  const turbo = path.join(root, 'node_modules', '.bin', 'turbo');
  await rm(turbo);
  await symlink(path.join(root, 'node_modules', 'missing-turbo'), turbo);

  const result = await runPreflight({ root });
  assert.equal(result.code, 42);
  assert.match(result.message, /turbo/);
});

test('installed dependencies pass when generated state is absent', async () => {
  const root = await fixture('clean');
  await installRequiredBins(root);

  assert.deepEqual(await runPreflight({ root }), { code: 0, message: 'checkout preflight passed' });
});

test('foreign-owned generated Next state is identified separately from source errors', async () => {
  const root = await fixture('foreign-next');
  await installRequiredBins(root);
  const generated = path.join(root, 'apps', 'web', '.next', 'types', 'validator.ts');
  await mkdir(path.dirname(generated), { recursive: true });
  await writeFile(generated, 'generated output');

  const result = await runPreflight({ root, uid: (process.getuid?.() ?? 0) + 1 });
  assert.equal(result.code, 43);
  assert.match(result.message, /MOSAIC_PREFLIGHT_GENERATED_STATE/);
  assert.match(result.message, /foreign-owned/);
});

test('a generated marker mismatch is identified separately from source errors', async () => {
  const root = await fixture('stale-next');
  await installRequiredBins(root);
  const generated = path.join(root, 'apps', 'web', '.next', 'types', 'validator.ts');
  await mkdir(path.dirname(generated), { recursive: true });
  await writeFile(generated, 'stale generated output');
  await writeFile(path.join(root, 'apps', 'web', '.next', '.mosaic-source-hash'), 'old-source');

  const result = await runPreflight({ root });
  assert.equal(result.code, 43);
  assert.match(result.message, /MOSAIC_PREFLIGHT_GENERATED_STATE/);
  assert.match(result.message, /apps\/web\/\.next/);
  assert.match(result.message, /pnpm clean:generated/);
});

test('a matching generation marker accepts incremental output with mixed mtimes', async () => {
  const root = await fixture('incremental-next');
  await installRequiredBins(root);
  const generated = path.join(root, 'apps', 'web', '.next', 'types', 'validator.ts');
  await mkdir(path.dirname(generated), { recursive: true });
  await writeFile(generated, 'unchanged generated output');
  await utimes(generated, new Date('2020-01-01T00:00:00Z'), new Date('2020-01-01T00:00:00Z'));
  const fresh = path.join(root, 'apps', 'web', '.next', 'types', 'routes.ts');
  await writeFile(fresh, 'fresh generated output');
  await writeFile(
    path.join(root, 'apps', 'web', '.next', '.mosaic-source-hash'),
    await sourceFingerprint(root),
  );

  assert.deepEqual(await runPreflight({ root }), { code: 0, message: 'checkout preflight passed' });
});