import assert from 'node:assert/strict';
import { spawn } from 'node:child_process';
import fs from 'node:fs';
import http from 'node:http';
import os from 'node:os';
import path from 'node:path';
import test from 'node:test';

import {
  assertStateSnapshot,
  createStateSnapshot,
  normalizeStoredState,
} from '../../src/shared/contracts/state.js';

const root = path.resolve(import.meta.dirname, '../..');

function listen(server) {
  return new Promise((resolve) => server.listen(0, '127.0.0.1', () => resolve(server.address().port)));
}

function close(server) {
  return new Promise((resolve) => server.close(resolve));
}

async function freePort() {
  const server = http.createServer();
  const port = await listen(server);
  await close(server);
  return port;
}

async function rawRequest(port, pathname, method = 'GET', body) {
  const response = await fetch(`http://127.0.0.1:${port}${pathname}`, {
    method,
    headers: { 'content-type': 'application/json' },
    body: body === undefined ? undefined : JSON.stringify(body),
  });
  const payload = await response.json();
  return { response, payload };
}

async function request(port, pathname, method = 'GET', body) {
  const { response, payload } = await rawRequest(port, pathname, method, body);
  assert.equal(response.ok, true, JSON.stringify(payload));
  return payload;
}

async function waitForState(port, child, stderr) {
  for (let attempt = 0; attempt < 100; attempt += 1) {
    if (child.exitCode !== null) throw new Error(`Harbor exited early: ${stderr()}`);
    try {
      return await request(port, '/api/state');
    } catch {
      await new Promise((resolve) => setTimeout(resolve, 20));
    }
  }
  throw new Error(`Harbor did not start: ${stderr()}`);
}

test('state v1 normalizes legacy storage and validates the canonical snapshot', () => {
  const stored = normalizeStoredState({
    subscriptionUrl: 'https://provider.example/subscription/test',
    selectedTag: ' legacy ',
    servers: [{ tag: ' legacy ', type: 'vless', server: 'vpn.example', server_port: 443 }],
  });
  const snapshot = createStateSnapshot({
    storedState: stored,
    runtime: { running: true, startedAt: '2026-07-11T10:00:00.000Z' },
    gatewayAuto: null,
    appMode: 'gateway',
    configExists: true,
    subscriptionHost: 'provider.example/…',
    now: new Date('2026-07-11T12:00:00.000Z'),
  });

  assert.equal(snapshot.apiVersion, 1);
  assert.deepEqual(snapshot.selection, {
    desiredServerId: 'legacy',
    appliedServerId: 'legacy',
  });
  assert.equal(snapshot.connection.process, 'running');
  assert.equal(JSON.stringify(snapshot).includes(stored.subscriptionUrl), false);
  assert.throws(
    () => assertStateSnapshot({ ...snapshot, revision: -1 }),
    /Invalid Harbor state snapshot v1/,
  );
});

test('GET and domain mutations return one state shape with monotonic revisions', async (t) => {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'harbor-state-contract-'));
  const binDir = path.join(dir, 'bin');
  const config = {
    outbounds: [{
      type: 'vless',
      tag: 'test-vpn',
      server: 'vpn.example.test',
      server_port: 443,
      uuid: '00000000-0000-4000-8000-000000000000',
      tls: { enabled: true },
    }],
  };
  fs.mkdirSync(binDir);
  const singboxPath = path.join(binDir, 'sing-box');
  const workingSingbox = `#!/usr/bin/env node
if (process.argv[2] === 'check') process.exit(0);
if (process.argv[2] === 'version') {
  console.log('sing-box version 1.12.13');
  process.exit(0);
}
process.on('SIGTERM', () => process.exit(0));
setInterval(() => {}, 60_000);
`;
  fs.writeFileSync(singboxPath, workingSingbox);
  fs.chmodSync(singboxPath, 0o755);

  const subscriptionServer = http.createServer((req, res) => {
    if (req.url === '/unavailable') {
      res.writeHead(503);
      return res.end('unavailable');
    }
    res.writeHead(200, {
      'content-type': 'application/json',
      'subscription-userinfo': 'upload=10; download=20; total=100',
    });
    res.end(JSON.stringify(config));
  });
  const subscriptionPort = await listen(subscriptionServer);
  const subscriptionUrl = `http://127.0.0.1:${subscriptionPort}/subscription/test`;
  fs.writeFileSync(path.join(dir, 'state.json'), JSON.stringify({
    subscriptionUrl,
    selectedTag: 'test-vpn',
    servers: [{ tag: 'test-vpn', type: 'vless', server: 'vpn.example.test', server_port: 443 }],
  }));
  fs.writeFileSync(path.join(dir, 'subscription-cache.json'), JSON.stringify({
    url: subscriptionUrl,
    config,
  }));

  const port = await freePort();
  const child = spawn(process.execPath, ['src/server/index.js'], {
    cwd: root,
    env: {
      ...process.env,
      APP_MODE: 'client',
      DATA_DIR: dir,
      PORT: String(port),
      PATH: `${binDir}:${process.env.PATH}`,
      HARBOR_HOST_NETWORK_STATE: path.join(dir, 'missing-network.json'),
    },
    stdio: ['ignore', 'ignore', 'pipe'],
  });
  let stderr = '';
  child.stderr.on('data', (chunk) => { stderr += chunk; });
  t.after(async () => {
    child.kill('SIGTERM');
    if (child.exitCode === null) await new Promise((resolve) => child.once('exit', resolve));
    await close(subscriptionServer);
    fs.rmSync(dir, { recursive: true, force: true });
  });

  const initial = await waitForState(port, child, () => stderr);
  const version = await request(port, '/api/version');
  assert.deepEqual(version, {
    apiVersion: 1,
    location: 'mac',
    components: { macClient: '0.1.0' },
    runtime: { singBox: '1.12.13' },
  });
  assertStateSnapshot(initial);
  assert.equal(initial.selection.appliedServerId, 'test-vpn');
  assert.equal(JSON.stringify(initial).includes(subscriptionUrl), false);
  const stateKeys = Object.keys(initial).sort();
  let revision = initial.revision;

  const invalidSubscription = await rawRequest(
    port,
    '/api/subscription/validate',
    'POST',
    { url: 'not-a-url' },
  );
  assert.equal(invalidSubscription.response.status, 400);
  assert.deepEqual(
    {
      code: invalidSubscription.payload.error.code,
      retryable: invalidSubscription.payload.error.retryable,
    },
    { code: 'SUBSCRIPTION_INVALID', retryable: false },
  );
  assert.equal(typeof invalidSubscription.payload.error.correlationId, 'string');

  const providerUnavailable = await rawRequest(
    port,
    '/api/subscription/validate',
    'POST',
    { url: `http://127.0.0.1:${subscriptionPort}/unavailable` },
  );
  assert.equal(providerUnavailable.response.status, 502);
  assert.equal(providerUnavailable.payload.error.code, 'PROVIDER_UNAVAILABLE');
  assert.equal(providerUnavailable.payload.error.retryable, true);

  const missingServer = await rawRequest(
    port,
    '/api/apply',
    'POST',
    { selectedTag: 'missing-server' },
  );
  assert.equal(missingServer.response.status, 404);
  assert.equal(missingServer.payload.error.code, 'SERVER_NOT_FOUND');
  assert.equal((await request(port, '/api/state')).selection.desiredServerId, 'test-vpn');

  async function stateResponse(pathname, method = 'POST', body) {
    const result = await request(port, pathname, method, body);
    assert.deepEqual(Object.keys(result.state).sort(), stateKeys);
    assertStateSnapshot(result.state);
    return result;
  }

  async function mutation(pathname, method = 'POST', body) {
    const result = await stateResponse(pathname, method, body);
    assert.ok(result.state.revision > revision, `${pathname} did not increase revision`);
    revision = result.state.revision;
    return result;
  }

  await stateResponse('/api/subscription/validate', 'POST', { url: subscriptionUrl });
  await mutation('/api/subscription/fetch', 'POST', { url: subscriptionUrl });
  const applied = await mutation('/api/apply', 'POST', { selectedTag: 'test-vpn' });
  assert.deepEqual(applied.state.selection, {
    desiredServerId: 'test-vpn',
    appliedServerId: 'test-vpn',
  });
  assert.equal(applied.state.connection.process, 'running');
  assert.equal((await mutation('/api/singbox/stop')).state.connection.desired, 'stopped');
  assert.equal((await mutation('/api/singbox/restart')).state.connection.desired, 'running');

  fs.writeFileSync(singboxPath, `#!/usr/bin/env node
if (process.argv[2] === 'check') {
  require('node:fs').unlinkSync(process.argv[1]);
  process.exit(0);
}
`);
  fs.chmodSync(singboxPath, 0o755);
  const processFailure = await rawRequest(port, '/api/singbox/restart', 'POST');
  assert.equal(processFailure.response.status, 503);
  assert.equal(processFailure.payload.error.code, 'PROCESS_START_FAILED');
  assert.equal(processFailure.payload.error.retryable, true);
  fs.writeFileSync(singboxPath, workingSingbox);
  fs.chmodSync(singboxPath, 0o755);

  await mutation('/api/subscription/refresh');
  assert.equal((await mutation('/api/gateway-auto', 'POST', { enabled: false })).state.gatewayAuto.enabled, false);
  const forgotten = await mutation('/api/subscription', 'DELETE');
  assert.equal(forgotten.state.subscription.status, 'missing');
  assert.equal(forgotten.state.servers.length, 0);
  assert.deepEqual((await stateResponse('/api/servers/ping-all')).results, []);

  const missingConfig = await rawRequest(port, '/api/singbox/restart', 'POST');
  assert.equal(missingConfig.response.status, 422);
  assert.equal(missingConfig.payload.error.code, 'CONFIG_INVALID');
  assert.equal(missingConfig.payload.error.retryable, false);
});