import { readFileSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import { join } from 'node:path';
import test from 'node:test';
import assert from 'node:assert/strict';

const repoRoot = fileURLToPath(new URL('..', import.meta.url));
const read = (...parts) => readFileSync(join(repoRoot, ...parts), 'utf8');

const CANONICAL = ['portable', 'config-server', 'public', 'index.html'];
const SHIM = ['portable', 'advanced', 'Config.html'];
const SYNCED = ['u-claw-app', 'resources', 'Config.html'];

// There were three settings pages: this shim (748 lines), the served page, and a
// copy inside the Electron app. The shim could never work — it calls
// fetch('/api/config') with a relative path, which from file:// resolves to
// file:///api/config and is blocked, so Save failed silently for anyone who
// double-clicked it. One implementation now; this file is a redirect.
test('portable/Config.html is a redirect shim, not a second implementation', () => {
  const shim = read(...SHIM);
  assert.ok(shim.split('\n').length < 200, 'the shim should stay small');
  assert.doesNotMatch(
    shim,
    /fetch\(\s*['"`]\/api\//,
    'a file:// page cannot call a relative API path — that was the original bug',
  );
  assert.match(shim, /location\.replace/, 'the shim should redirect to the running server');
});

test('the shim probes the whole config-server port range', () => {
  const shim = read(...SHIM);
  const server = read('portable', 'config-server', 'server.js');
  const start = Number(server.match(/PORT_RANGE_START\s*=\s*(\d+)/)?.[1]);
  const end = Number(server.match(/PORT_RANGE_END\s*=\s*(\d+)/)?.[1]);
  assert.ok(Number.isInteger(start) && Number.isInteger(end), 'server must declare its port range');
  // Hardcoding 18788 is exactly what made Mac-Start.command open a dead page.
  assert.match(shim, new RegExp(`PORT_FROM\\s*=\\s*${start}`), `shim should probe from ${start}`);
  assert.match(shim, new RegExp(`PORT_TO\\s*=\\s*${end}`), `shim should probe to ${end}`);
});

test('the Electron copy is generated from the canonical page, not hand-maintained', () => {
  const sync = read('u-claw-app', 'scripts', 'sync-lib.js');
  assert.match(
    sync,
    /config-server['"],\s*['"]public['"],\s*['"]index\.html/,
    'sync-lib.js must copy from config-server/public/index.html',
  );
  assert.equal(
    read(...SYNCED),
    read(...CANONICAL),
    'u-claw-app/resources/Config.html is out of sync — run node u-claw-app/scripts/sync-lib.js',
  );
});

test('the shim explains what to do when nothing is listening', () => {
  const shim = read(...SHIM);
  // House rule: what happened, why, and one thing to do next.
  for (const key of ['what', 'why', 'action']) {
    assert.match(shim, new RegExp(`data-msg="${key}"`), `the offline state needs a "${key}" line`);
  }
  for (const locale of ['en', "'zh-CN'"]) {
    assert.match(shim, new RegExp(locale.replace(/[-']/g, (c) => `\\${c}`)), `shim should carry ${locale} strings`);
  }
});