import { spawnSync } from 'node:child_process';
import { chmodSync, existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join, resolve } from 'node:path';
import { afterAll, afterEach, beforeAll, describe, expect, it } from 'vitest';

import {
  ASSIMP_FALLBACK_DIRS,
  assimpInstallHint,
  assimpMissingMessage,
  detectAssimpBin,
  resolveAssimpBinary,
} from '../src/common/assimp';
import { convertModelFile } from '../src/models/model-convert';

/**
 * Assimp 缺失时的可诊断性。
 *
 * 背景（真实故障）：服务器没装 Assimp，上传 PMX 压缩包只得到
 *   GLB 直出：导出失败（ENOENT）：spawn assimp ENOENT
 *   glTF 直出：导出失败（ENOENT）：spawn assimp ENOENT
 * 用户看不出「缺什么、怎么装」。现在：
 *   * 转换前先定位二进制，找不到就一次性给出安装命令与查过的路径；
 *   * 定位逻辑覆盖 PATH 之外的常见目录（服务由 systemd 托管时 PATH 可能很窄）。
 */

let workRoot = '';
let fakeBin = '';

function findDeployLib(): string {
  const candidates = [
    resolve(process.cwd(), '..', 'deploy', 'assimp-lib.sh'),
    resolve(process.cwd(), 'deploy', 'assimp-lib.sh'),
    resolve(process.cwd(), '..', '..', 'deploy', 'assimp-lib.sh'),
  ];
  for (const candidate of candidates) {
    if (existsSync(candidate)) return candidate;
  }
  throw new Error(`找不到 deploy/assimp-lib.sh，候选路径：\n${candidates.join('\n')}`);
}

const ASSIMP_LIB = findDeployLib();

/** 写一个最小的假 assimp：只实现 `version` */
function writeFakeAssimp(path: string, versionLine = 'Assimp version 6.0.4'): string {
  mkdirSync(join(path, '..'), { recursive: true });
  writeFileSync(path, `#!/bin/bash\n[ "\${1:-}" = "version" ] && echo "${versionLine}"\nexit 0\n`);
  chmodSync(path, 0o755);
  return path;
}

beforeAll(() => {
  workRoot = mkdtempSync(join(tmpdir(), 'opendance-assimp-test-'));
  fakeBin = writeFakeAssimp(join(workRoot, 'bin', 'assimp'));
});

afterAll(() => {
  rmSync(workRoot, { recursive: true, force: true });
});

const savedPath = process.env.PATH;
afterEach(() => {
  process.env.PATH = savedPath;
});

describe('Assimp 定位（resolveAssimpBinary）', () => {
  it('能在 PATH 中找到可执行文件', () => {
    process.env.PATH = `${join(workRoot, 'bin')}:/usr/bin:/bin`;
    const result = resolveAssimpBinary('assimp');
    expect(result.found).toBe(true);
    expect(result.path).toBe(fakeBin);
  });

  it('显式绝对路径优先，不存在时 found=false 并给出查找记录', () => {
    const missing = join(workRoot, 'no-such-assimp');
    const result = resolveAssimpBinary(missing);
    expect(result.found).toBe(false);
    expect(result.searched).toContain(missing);

    const present = resolveAssimpBinary(fakeBin);
    expect(present.found).toBe(true);
    expect(present.path).toBe(fakeBin);
  });

  it('PATH 里没有时仍会查常见系统目录（systemd 服务 PATH 可能很窄）', () => {
    process.env.PATH = '/nonexistent-dir-only';
    const result = resolveAssimpBinary('assimp');
    // 结果取决于本机是否装了真实 assimp：两种都必须把常见目录查过
    for (const dir of ASSIMP_FALLBACK_DIRS) {
      expect(result.searched).toContain(join(dir, 'assimp'));
    }
    if (!result.found) expect(result.path).toBe('assimp');
  });
});

describe('Assimp 缺失时的错误信息', () => {
  it('包含二进制名、各发行版安装命令、替代办法与查过的路径', () => {
    const message = assimpMissingMessage('assimp', ['/usr/bin/assimp', '/usr/local/bin/assimp']);
    expect(message).toContain('assimp');
    expect(message).toContain('apt-get install -y assimp-utils');
    expect(message).toContain('dnf install -y assimp');
    expect(message).toContain('/usr/bin/assimp');
    expect(message).toContain('ASSIMP_BIN');
    expect(message).toContain('.glb / .vrm');
  });

  it('安装提示各发行版一条命令', () => {
    const hint = assimpInstallHint();
    for (const distro of ['Debian / Ubuntu', 'Alpine', 'Arch']) {
      expect(hint).toContain(distro);
    }
  });
});

describe('Assimp 可用性探测（detectAssimpBin）', () => {
  it('能执行时返回版本与路径', async () => {
    const probe = await detectAssimpBin(fakeBin);
    expect(probe.available).toBe(true);
    expect(probe.path).toBe(fakeBin);
    expect(probe.version).toContain('6.0.4');
  });

  it('找不到时 available=false 且 error 说明未安装', async () => {
    const probe = await detectAssimpBin(join(workRoot, 'no-such-assimp'));
    expect(probe.available).toBe(false);
    expect(probe.error).toContain('未安装');
    expect(probe.searched.length).toBeGreaterThan(0);
  });
});

describe('转换管线：Assimp 缺失时快速失败并给出可操作信息', () => {
  it('convertModelFile 抛出的错误包含安装命令，且不再出现两次 spawn ENOENT', async () => {
    let message = '';
    try {
      await convertModelFile(Buffer.from('PMX dummy'), 'Hatsune Miku.pmx', {
        assimpBin: join(workRoot, 'no-such-assimp'),
        timeoutMs: 5_000,
      });
      throw new Error('应当抛出异常');
    } catch (error) {
      message = error instanceof Error ? error.message : String(error);
    }
    expect(message).toContain('模型转换失败');
    expect(message).toContain('apt-get install -y assimp-utils');
    expect(message).toContain('ASSIMP_BIN');
    expect(message).not.toContain('ENOENT');
  });
});

describe('deploy/assimp-lib.sh：部署脚本共用的安装逻辑', () => {
  function runLib(script: string, path?: string) {
    // 覆盖 PATH 的用例里必须用绝对路径调 bash，否则连 bash 都找不到
    return spawnSync('/bin/bash', ['-c', `. "$1"; ${script}`, '_', ASSIMP_LIB], {
      encoding: 'utf8',
      timeout: 15000,
      env: { ...process.env, ...(path ? { PATH: path } : {}) },
    });
  }

  it('opendance_assimp_resolve 能在 PATH 中找到二进制', () => {
    const result = runLib('opendance_assimp_resolve', `${join(workRoot, 'bin')}:/usr/bin:/bin`);
    expect(result.stdout.trim()).toBe(fakeBin);
    expect(result.status).toBe(0);
  });

  it('opendance_assimp_resolve 在找不到时返回非 0 且无输出', () => {
    const result = runLib('opendance_assimp_resolve || echo MISSING', '/nonexistent-dir-only');
    // 本机若真的装了 assimp（/usr/bin），则跳过这条断言的严格性
    if (!existsSync('/usr/bin/assimp') && !existsSync('/usr/local/bin/assimp')) {
      expect(result.stdout.trim()).toBe('MISSING');
    }
    expect(result.status).toBe(0);
  });

  it('opendance_assimp_install_cmd 按包管理器给出对应命令', () => {
    const aptDir = join(workRoot, 'apt');
    mkdirSync(aptDir, { recursive: true });
    writeFileSync(join(aptDir, 'apt-get'), '#!/bin/bash\nexit 0\n');
    chmodSync(join(aptDir, 'apt-get'), 0o755);
    const result = runLib('opendance_assimp_install_cmd', `${aptDir}:/usr/bin:/bin`);
    expect(result.stdout).toContain('apt-get install -y assimp-utils');
  });

  it('opendance_assimp_install 调用包管理器安装 assimp-utils（离线失败也不抛）', () => {
    const aptDir = join(workRoot, 'apt');
    const log = join(aptDir, 'calls.log');
    rmSync(log, { force: true });
    writeFileSync(join(aptDir, 'apt-get'), `#!/bin/bash\necho "apt-get $*" >> "${log}"\nexit 0\n`);
    chmodSync(join(aptDir, 'apt-get'), 0o755);
    const result = runLib('opendance_assimp_install', `${aptDir}:/usr/bin:/bin`);
    expect(result.status).toBe(0);
    const calls = existsSync(log) ? readFileSync(log, 'utf8') : '';
    expect(calls).toContain('apt-get install -y -qq assimp-utils');
  });

  it('非常规目录需要写 ASSIMP_BIN，标准目录不需要', () => {
    expect(runLib(`opendance_assimp_needs_env_path ${join(workRoot, 'bin', 'assimp')} && echo YES`).stdout).toContain('YES');
    expect(runLib('opendance_assimp_needs_env_path /usr/bin/assimp || echo NO').stdout).toContain('NO');
  });
});