import { readFileSync } from 'node:fs';
import { join, resolve } from 'node:path';
import { afterEach, describe, expect, it } from 'vitest';
import {
  PACKAGE_NAME,
  UNKNOWN_VERSION,
  packageJsonCandidates,
  parsePackageVersion,
  resetAppVersionCache,
  resolveAppVersion,
} from '../src/config/app-version';

/**
 * 版本号展示的**运行时唯一来源**（文档 §11.1 / §11.2）。
 *
 * 这里守护的是一个真实发生过的缺陷：原来 `/health` 用
 * `process.env.npm_package_version ?? '0.1.0'`，而正式部署方式是原生服务
 * （`ExecStart=node dist/main.js`），npm 不参与 → 该环境变量为 undefined →
 * `/health` 在真实部署里永远报 **0.1.0**，与管理端左下角展示的 vX.Y.Z 不一致，
 * 直接违反「可核对：Web 端至少与 GET /health 的 version 一致」。
 */

const serverPackageJson = JSON.parse(
  readFileSync(resolve(__dirname, '..', 'package.json'), 'utf8'),
) as { name: string; version: string };

afterEach(() => {
  delete process.env.APP_VERSION;
  resetAppVersionCache();
});

describe('parsePackageVersion（纯函数：只在包名与格式都对时才认）', () => {
  it('接受本项目的 package.json', () => {
    expect(
      parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME, version: '1.2.3' })),
    ).toBe('1.2.3');
  });

  it('接受带预发布后缀的版本', () => {
    expect(
      parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME, version: '1.2.3-rc.1' })),
    ).toBe('1.2.3-rc.1');
  });

  it('拒绝包名不匹配的文件（避免读到上层仓库的 package.json）', () => {
    expect(parsePackageVersion(JSON.stringify({ name: 'some-other-pkg', version: '9.9.9' }))).toBeNull();
  });

  it('拒绝缺少 name / version 的文件', () => {
    expect(parsePackageVersion(JSON.stringify({ version: '1.2.3' }))).toBeNull();
    expect(parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME }))).toBeNull();
    expect(parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME, version: 123 }))).toBeNull();
  });

  it('拒绝非版本串（例如 workspace:*）', () => {
    expect(parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME, version: 'workspace:*' }))).toBeNull();
    expect(parsePackageVersion(JSON.stringify({ name: PACKAGE_NAME, version: '^1.0.0' }))).toBeNull();
  });

  it('拒绝非法 JSON 与非对象', () => {
    expect(parsePackageVersion('{ 不是 JSON')).toBeNull();
    expect(parsePackageVersion('"字符串"')).toBeNull();
    expect(parsePackageVersion('null')).toBeNull();
  });
});

describe('resolveAppVersion（运行时解析）', () => {
  it('解析结果等于 web-server/package.json 的 version（单一来源）', () => {
    expect(resolveAppVersion()).toBe(serverPackageJson.version);
  });

  it('与 package.json 里声明的包名一致（校验逻辑没有把别的包读进来）', () => {
    expect(serverPackageJson.name).toBe(PACKAGE_NAME);
  });

  it('未通过 npm 启动时也能拿到真实版本（不依赖 npm_package_version）', () => {
    // 模拟原生部署：systemd 直接跑 node dist/main.js，没有 npm 环境变量
    const saved = process.env.npm_package_version;
    delete process.env.npm_package_version;
    delete process.env.APP_VERSION;
    resetAppVersionCache();
    try {
      const version = resolveAppVersion();
      expect(version).toBe(serverPackageJson.version);
      expect(version).not.toBe('0.1.0');
      expect(version).not.toBe(UNKNOWN_VERSION);
    } finally {
      if (saved !== undefined) process.env.npm_package_version = saved;
      resetAppVersionCache();
    }
  });

  it('APP_VERSION 环境变量可显式覆盖（运维不重新打包也能改）', () => {
    process.env.APP_VERSION = '9.8.7';
    resetAppVersionCache();
    expect(resolveAppVersion()).toBe('9.8.7');
  });

  it('候选路径包含工作目录（systemd WorkingDirectory=web-server）', () => {
    const candidates = packageJsonCandidates();
    expect(candidates).toContain(join(process.cwd(), 'package.json'));
    // 去重：同一路径不应出现两次
    expect(new Set(candidates).size).toBe(candidates.length);
  });

  it('结果稳定（同一进程内缓存，不会来回变）', () => {
    const first = resolveAppVersion();
    const second = resolveAppVersion();
    expect(first).toBe(second);
  });
});