import assert from 'node:assert/strict';
import { spawn } from 'node:child_process';
import { once } from 'node:events';
import { copyFileSync, mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import test from 'node:test';

const script = fileURLToPath(new URL('./dev-backend.mjs', import.meta.url));

function fixture(t, source, options = {}) {
  const root = mkdtempSync(path.join(tmpdir(), 'creator-backend-test-'));
  mkdirSync(path.join(root, 'scripts'));
  mkdirSync(path.join(root, 'bin'));
  copyFileSync(script, path.join(root, 'scripts/dev-backend.mjs'));
  if (options.envFile) writeFileSync(path.join(root, '.env'), options.envFile);
  writeFileSync(path.join(root, 'bin/air'), `#!${process.execPath}\n${source}`, { mode: 0o755 });
  const children = [];
  t.after(async () => {
    for (const child of children) {
      if (child.backendPID) {
        try { process.kill(child.backendPID, 'SIGTERM'); } catch (error) {
          if (error.code !== 'ESRCH') throw error;
        }
      }
      if (child.exitCode === null && child.signalCode === null) {
        const closed = once(child, 'close');
        child.kill('SIGTERM');
        await closed;
      }
    }
    rmSync(root, { recursive: true, force: true });
  });
  return () => {
    const child = spawn(process.execPath, [path.join(root, 'scripts/dev-backend.mjs')], {
      env: { ...process.env, PATH: options.noFlock ? path.join(root, 'bin') : `${path.join(root, 'bin')}:${process.env.PATH}` },
      stdio: ['ignore', 'pipe', 'pipe'],
    });
    children.push(child);
    child.errors = '';
    child.output = '';
    child.stdout.on('data', (chunk) => {
      child.output += chunk;
      const pid = /ready:(\d+)/.exec(chunk.toString());
      if (pid) child.backendPID = Number(pid[1]);
    });
    child.stderr.on('data', (chunk) => { child.errors += chunk; });
    return child;
  };
}

async function ready(child) {
  const [chunk] = await once(child.stdout, 'data', { signal: AbortSignal.timeout(1500) });
  assert.match(chunk.toString(), /ready:/);
}

function exited(child) {
  return once(child, 'close', { signal: AbortSignal.timeout(1500) });
}

const server = `
process.on('SIGTERM', () => process.exit(0));
process.on('SIGINT', () => process.exit(0));
console.log('ready:' + process.pid);
setInterval(() => {}, 1000);
`;

test('rejects a second backend without disturbing the first', { timeout: 5000 }, async (t) => {
  const start = fixture(t, server);
  const first = start();
  await ready(first);
  const second = start();
  const [code] = await exited(second);
  assert.equal(code, 73);
  assert.match(second.errors, /后台已在运行/);
  assert.equal(first.exitCode, null);
});

test('forwards termination and releases the lock for the next launch', { timeout: 5000 }, async (t) => {
  const start = fixture(t, server);
  const first = start();
  await ready(first);
  const stopped = exited(first);
  first.kill('SIGTERM');
  const [code] = await stopped;
  assert.equal(code, 0);
  const second = start();
  await ready(second);
  const closed = exited(second);
  second.kill('SIGINT');
  assert.equal((await closed)[0], 0);
});

test('reports backend startup failure and allows a retry', { timeout: 5000 }, async (t) => {
  const start = fixture(t, "console.error('build failed'); process.exit(17);");
  const first = start();
  assert.equal((await exited(first))[0], 17);
  assert.match(first.errors, /build failed/);
  const second = start();
  assert.equal((await exited(second))[0], 17);
});

test('preserves environment configuration when launching through the lock', { timeout: 5000 }, async (t) => {
  const start = fixture(t, "console.log(process.env.LISTEN_ADDR); console.log(process.env.CREATORHUB_CREDENTIAL_MASTER_KEY);", {
    envFile: `\n# ignored comment\ninvalid line\nLISTEN_ADDR=:19091\nLISTEN_ADDR=:19092\nCREATORHUB_CREDENTIAL_MASTER_KEY=${Buffer.alloc(32, 1).toString('base64')}\nCONTROL_PLANE_USERNAME=test\nCONTROL_PLANE_PASSWORD=test\nDATABASE_URL=postgres://test\nWEB_DIR=/tmp/web\nCREATOR_COVER_DIR=/tmp/covers\nCREATORHUB_CREDENTIAL_STORE_DIR=/tmp/credentials\nLOG_LEVEL=info\nNATIVE_GATEWAY_ENDPOINT=http://127.0.0.1:28187\n`,
  });
  const child = start();
  assert.equal((await exited(child))[0], 0);
  assert.match(child.output, /:19091/);
  assert.match(child.output, /AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE=/);
});

test('preserves a signal-caused backend failure instead of reporting success', { timeout: 5000 }, async (t) => {
  const start = fixture(t, server);
  const child = start();
  await ready(child);
  const closed = exited(child);
  process.kill(child.backendPID, 'SIGKILL');
  assert.equal((await closed)[0], 137);
});

test('reports a missing lock command instead of silently exiting successfully', { timeout: 5000 }, async (t) => {
  const start = fixture(t, server, { noFlock: true });
  const child = start();
  assert.equal((await exited(child))[0], 1);
  assert.match(child.errors, /启动失败.*ENOENT/);
});