import assert from 'node:assert/strict';
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 { fileURLToPath } from 'node:url';

import { generateKeyPairSync } from 'node:crypto';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const SECONDS_PER_DAY = 86400;

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

function request(port, method, pathname, { body } = {}) {
  return new Promise((resolve, reject) => {
    const headers = { 'Content-Type': 'application/json' };
    const req = http.request(
      { hostname: '127.0.0.1', port, method, path: pathname, headers },
      (res) => {
        const chunks = [];
        res.on('data', (c) => chunks.push(c));
        res.on('end', () => {
          const raw = Buffer.concat(chunks).toString('utf8');
          resolve({ status: res.statusCode, body: raw ? JSON.parse(raw) : null });
        });
      },
    );
    req.on('error', reject);
    if (body) req.write(JSON.stringify(body));
    req.end();
  });
}

async function makeServer(dataPath) {
  process.env.SKIP_LICENSE_LISTEN = '1';
  const { createServer } = await import('../src/server.mjs');
  const { privateKey } = generateKeyPairSync('ed25519');
  const pem = privateKey.export({ type: 'pkcs8', format: 'pem' });
  process.env.DND_LICENSE_DATA_PATH = dataPath;
  return createServer({ privateKeyPem: pem, adminToken: 'test-admin' });
}

function writeData(dataPath, productKeys, activations = {}) {
  fs.writeFileSync(
    dataPath,
    JSON.stringify({
      productKeys,
      revokedSubs: [],
      revokedKeys: [],
      activations,
    }),
  );
}

function tokenPayload(token) {
  return JSON.parse(Buffer.from(token.split('.')[0], 'base64url').toString('utf8'));
}

void test('POST /v1/activate fixed key sets exp from expiresAtSec', async () => {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'lic-'));
  const dataPath = path.join(tmp, 'data.json');
  writeData(dataPath, [
    {
      key: 'TTRPG-FIXED',
      sub: 'lic_fixed',
      pid: 'dnd_player',
      maxDevices: 2,
      expiresAtSec: 1893456000,
    },
  ]);

  const server = await makeServer(dataPath);
  const port = await listen(server);
  try {
    const res = await request(port, 'POST', '/v1/activate', {
      body: { productKey: 'TTRPG-FIXED', deviceId: 'dev-a' },
    });
    assert.equal(res.status, 200);
    assert.equal(tokenPayload(res.body.token).exp, 1893456000);
  } finally {
    server.close();
    fs.rmSync(tmp, { recursive: true, force: true });
  }
});

void test('POST /v1/activate period key starts countdown on first activation', async () => {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'lic-'));
  const dataPath = path.join(tmp, 'data.json');
  writeData(dataPath, [
    {
      key: 'TTRPG-PERIOD',
      sub: 'lic_period',
      pid: 'dnd_player',
      maxDevices: 2,
      validDays: 30,
    },
  ]);

  const server = await makeServer(dataPath);
  const port = await listen(server);
  try {
    const before = Math.floor(Date.now() / 1000);
    const res = await request(port, 'POST', '/v1/activate', {
      body: { productKey: 'TTRPG-PERIOD', deviceId: 'dev-a' },
    });
    const after = Math.floor(Date.now() / 1000);
    assert.equal(res.status, 200);

    const payload = tokenPayload(res.body.token);
    assert.ok(payload.exp >= before + 30 * SECONDS_PER_DAY);
    assert.ok(payload.exp <= after + 30 * SECONDS_PER_DAY);

    const data = JSON.parse(fs.readFileSync(dataPath, 'utf8'));
    const pk = data.productKeys[0];
    assert.ok(pk.activatedAtSec >= before);
    assert.equal(pk.licenseExpSec, payload.exp);
  } finally {
    server.close();
    fs.rmSync(tmp, { recursive: true, force: true });
  }
});

void test('POST /v1/activate period key re-activation keeps same exp', async () => {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'lic-'));
  const dataPath = path.join(tmp, 'data.json');
  const licenseExpSec = 1700000000 + 365 * SECONDS_PER_DAY;
  writeData(
    dataPath,
    [
      {
        key: 'TTRPG-PERIOD',
        sub: 'lic_period',
        pid: 'dnd_player',
        maxDevices: 2,
        validDays: 365,
        activatedAtSec: 1700000000,
        licenseExpSec,
      },
    ],
    { lic_period: ['dev-a'] },
  );

  const server = await makeServer(dataPath);
  const port = await listen(server);
  try {
    const res = await request(port, 'POST', '/v1/activate', {
      body: { productKey: 'TTRPG-PERIOD', deviceId: 'dev-a' },
    });
    assert.equal(res.status, 200);
    assert.equal(tokenPayload(res.body.token).exp, licenseExpSec);
  } finally {
    server.close();
    fs.rmSync(tmp, { recursive: true, force: true });
  }
});

void test('POST /v1/activate period key second device shares license exp', async () => {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'lic-'));
  const dataPath = path.join(tmp, 'data.json');
  const licenseExpSec = 1700000000 + 90 * SECONDS_PER_DAY;
  writeData(
    dataPath,
    [
      {
        key: 'TTRPG-PERIOD',
        sub: 'lic_period',
        pid: 'dnd_player',
        maxDevices: 2,
        validDays: 90,
        activatedAtSec: 1700000000,
        licenseExpSec,
      },
    ],
    { lic_period: ['dev-a'] },
  );

  const server = await makeServer(dataPath);
  const port = await listen(server);
  try {
    const res = await request(port, 'POST', '/v1/activate', {
      body: { productKey: 'TTRPG-PERIOD', deviceId: 'dev-b' },
    });
    assert.equal(res.status, 200);
    const payload = tokenPayload(res.body.token);
    assert.equal(payload.exp, licenseExpSec);
    assert.equal(payload.did, 'dev-b');
  } finally {
    server.close();
    fs.rmSync(tmp, { recursive: true, force: true });
  }
});