import os from "node:os";
import fs from "node:fs";
import path from "node:path";
import https from "node:https";
import { pipeline } from "node:stream/promises";
import { createWriteStream, createReadStream } from "node:fs";
import { createGunzip } from "node:zlib";
import { extract } from "tar";

const base = "https://api.github.com/repos/pocketbase/pocketbase/releases/latest";
const proxy = 'https://gh-proxy.org/';
const program = 'program';
const directory = program + '/' + 'pocketbase';

// 获取系统平台和架构
function getPlatformInfo() {
  const platform = os.platform(); // 'darwin', 'linux', 'win32'
  const arch = os.arch(); // 'x64', 'arm64', etc.

  let platformName = '';
  let archName = '';

  // 映射平台名称
  switch (platform) {
    case 'darwin':
      platformName = 'darwin';
      break;
    case 'linux':
      platformName = 'linux';
      break;
    case 'win32':
      platformName = 'windows';
      break;
    default:
      throw new Error(`Unsupported platform: ${platform}`);
  }

  // 映射架构名称
  switch (arch) {
    case 'x64':
      archName = 'amd64';
      break;
    case 'arm64':
      archName = 'arm64';
      break;
    default:
      throw new Error(`Unsupported architecture: ${arch}`);
  }

  return { platformName, archName };
}

// 下载文件
async function downloadFile(url: string, destPath: string): Promise<void> {
  return new Promise((resolve, reject) => {
    https.get(url, (response) => {
      // 处理重定向
      if (response.statusCode === 302 || response.statusCode === 301) {
        const redirectUrl = response.headers.location;
        if (redirectUrl) {
          downloadFile(redirectUrl, destPath).then(resolve).catch(reject);
          return;
        }
      }

      if (response.statusCode !== 200) {
        reject(new Error(`Failed to download: ${response.statusCode}`));
        return;
      }

      const fileStream = createWriteStream(destPath);
      response.pipe(fileStream);

      fileStream.on('finish', () => {
        fileStream.close();
        resolve();
      });

      fileStream.on('error', reject);
    }).on('error', reject);
  });
}

// 解压 zip 文件 (Windows)
async function extractZip(zipPath: string, destDir: string): Promise<void> {
  const AdmZip = require('adm-zip');
  const zip = new AdmZip(zipPath);
  zip.extractAllTo(destDir, true);
}

// 提取 tar.gz 文件 (Linux/macOS)
export async function extractTarGz(tarGzPath: string, destDir: string): Promise<void> {
  await fs.promises.mkdir(destDir, { recursive: true });

  await pipeline(
    createReadStream(tarGzPath),
    createGunzip(),
    extract({ cwd: destDir })
  );
}

// 主函数：下载并解压 PocketBase
export async function download(): Promise<void> {
  try {
    const { platformName, archName } = getPlatformInfo();

    console.log(`检测到系统: ${platformName} ${archName}`);

    // 获取最新版本信息
    const response = await fetch(base);
    if (!response.ok) {
      throw new Error(`Failed to fetch release info: ${response.status}`);
    }

    const releaseData = await response.json();
    const tagName = releaseData.tag_name.replace(/^v/, '');
    const assets = releaseData.assets;

    // 查找匹配的资源文件
    const fileExtension = '.zip';
    const assetPattern = `pocketbase_${tagName}_${platformName}_${archName}${fileExtension}`;

    const asset = assets.find((a: any) => a.name.includes(assetPattern));

    if (!asset) {
      throw new Error(`No matching asset found for ${platformName} ${archName}`);
    }

    console.log(`找到资源: ${asset.name}`);
    console.log(`下载链接: ${asset.browser_download_url}`);

    // 创建目录
    await fs.promises.mkdir(directory, { recursive: true });

    const downloadPath = path.join(directory, asset.name);

    // 下载文件
    console.log('开始下载...');
    await downloadFile(asset.browser_download_url, downloadPath);
    console.log('下载完成');

    // 解压文件
    console.log('开始解压...');
    await extractZip(downloadPath, directory);

    console.log('解压完成');

    // 给可执行文件添加执行权限（非 Windows）
    if (os.platform() !== 'win32') {
      const finalPath = path.join(directory, 'pocketbase');
      fs.chmodSync(finalPath, 0o755);
      console.log('已添加执行权限');
    }

    // 删除压缩包
    await fs.promises.unlink(downloadPath);
    console.log('清理完成');

    console.log(`PocketBase 已安装到: ${path.resolve(directory)}`);
  } catch (error) {
    console.error('下载或解压失败:', error);
    throw error;
  }
}

// 如果直接运行此文件
if (require.main === module) {
  download();
}