#!/usr/bin/env node

import {spawnSync} from 'node:child_process';
import {existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync} from 'node:fs';
import {tmpdir} from 'node:os';
import path from 'node:path';

const BACKUP_SCRIPT = path.resolve('scripts/database-backup-to-oss.mjs');
const tmpRoot = mkdtempSync(path.join(tmpdir(), 'genarrative-database-backup-check-'));
const failures = [];

try {
  main();
} finally {
  rmSync(tmpRoot, {recursive: true, force: true});
}

if (failures.length > 0) {
  console.error('[check:database-backup] FAILED');
  for (const failure of failures) {
    console.error(`- ${failure}`);
  }
  process.exit(1);
}

console.log('[check:database-backup] OK');

function main() {
  assertInsufficientSpaceStopsBeforeServiceChanges();
  assertArchiveFailureStillRestoresDependentServices();
}

function assertInsufficientSpaceStopsBeforeServiceChanges() {
  const fixture = createFixture('insufficient-space');
  const result = runBackup(fixture, [
    '--stop-service',
    'spacetimedb.service',
    '--restart-service-after',
    'genarrative-api.service',
    '--min-free-bytes',
    '999999999999999999',
  ]);

  assertStatus(result, 1, '空间不足时必须失败。');
  assertIncludes(result.stdout, '备份空间预检', '空间不足失败前应打印空间预检。');
  assertIncludes(result.stderr, '剩余空间不足', '空间不足失败应说明剩余空间不足。');
  assertFileMissing(fixture.systemctlLog, '空间不足时不能调用 systemctl。');
  assertFileMissing(fixture.tarLog, '空间不足时不能调用 tar。');
}

function assertArchiveFailureStillRestoresDependentServices() {
  const fixture = createFixture('tar-failure');
  const result = runBackup(fixture, [
    '--stop-service',
    'spacetimedb.service',
    '--restart-service-after',
    'genarrative-api.service',
    '--restart-service-after',
    'genarrative-external-generation-worker@1.service',
    '--restart-service-after',
    'genarrative-external-generation-controller.service',
    '--min-free-bytes',
    '1',
  ]);

  assertStatus(result, 1, 'tar 失败时备份脚本必须失败。');
  assertIncludes(result.stderr, 'fake tar failure', 'tar 失败原因应保留在错误输出中。');
  const systemctlLog = readFile(fixture.systemctlLog);
  const expectedCommands = [
    'systemctl stop spacetimedb.service',
    'systemctl start spacetimedb.service',
    'systemctl restart genarrative-api.service',
    'systemctl restart genarrative-external-generation-worker@1.service',
    'systemctl restart genarrative-external-generation-controller.service',
  ];
  for (const command of expectedCommands) {
    assertIncludes(systemctlLog, command, `tar 失败后必须执行: ${command}`);
  }
}

function createFixture(name) {
  const root = path.join(tmpRoot, name);
  const binDir = path.join(root, 'bin');
  const dataDir = path.join(root, 'data');
  const workDir = path.join(root, 'work');
  const systemctlLog = path.join(root, 'systemctl.log');
  const tarLog = path.join(root, 'tar.log');
  mkdirSync(binDir, {recursive: true});
  mkdirSync(dataDir, {recursive: true});
  writeFileSync(path.join(dataDir, 'sample.bin'), 'sample backup payload\n', 'utf8');
  writeExecutable(
    path.join(binDir, 'systemctl'),
    `#!/usr/bin/env bash
printf 'systemctl %s\\n' "$*" >> "${systemctlLog}"
exit 0
`,
  );
  writeExecutable(
    path.join(binDir, 'tar'),
    `#!/usr/bin/env bash
printf 'tar %s\\n' "$*" >> "${tarLog}"
echo 'fake tar failure' >&2
exit 2
`,
  );
  return {root, binDir, dataDir, workDir, systemctlLog, tarLog};
}

function runBackup(fixture, extraArgs = []) {
  return spawnSync(
    process.execPath,
    [
      BACKUP_SCRIPT,
      '--data-dir',
      fixture.dataDir,
      '--work-dir',
      fixture.workDir,
      '--bucket',
      'genarrative-test',
      '--endpoint',
      'oss-cn-shanghai.aliyuncs.com',
      '--access-key-id',
      'test',
      '--access-key-secret',
      'test',
      ...extraArgs,
    ],
    {
      cwd: process.cwd(),
      encoding: 'utf8',
      env: {
        ...process.env,
        PATH: `${fixture.binDir}${path.delimiter}${process.env.PATH ?? ''}`,
      },
    },
  );
}

function writeExecutable(filePath, content) {
  writeFileSync(filePath, content, 'utf8');
  spawnSync('chmod', ['0755', filePath], {encoding: 'utf8'});
}

function readFile(filePath) {
  return existsSync(filePath) ? readFileSync(filePath, 'utf8') : '';
}

function assertStatus(result, expected, reason) {
  const actual = result.status ?? 0;
  if (actual !== expected) {
    failures.push(
      `${reason} 预期退出码 ${expected}，实际 ${actual}。\nstdout:\n${result.stdout}\nstderr:\n${result.stderr}`,
    );
  }
}

function assertIncludes(content, expected, reason) {
  if (!String(content).includes(expected)) {
    failures.push(`${reason} 缺少: ${expected}`);
  }
}

function assertFileMissing(filePath, reason) {
  if (existsSync(filePath)) {
    failures.push(`${reason} 实际存在: ${filePath}\n${readFile(filePath)}`);
  }
}