Feat: implement Clash Meta mrs format

Build/lib/convert-clash-meta-mrs.ts

@@ -0,0 +1,57 @@
+import path from 'path';
+import fs from 'fs';
+import fsp from 'fs/promises';
+import { Readable } from 'stream';
+import { pipeline } from 'stream/promises';
+import zlib from 'zlib';
+import { async as ezspawn } from '@jsdevtools/ez-spawn';
+
+const mihomoBinaryDir = path.join(__dirname, '../../node_modules/.cache/mihomo');
+const mihomoBinaryPath = path.join(mihomoBinaryDir, 'mihomo');
+
+const mihomoBinaryUrl: Partial<Record<NodeJS.Platform, Partial<Record<NodeJS.Architecture, string>>>> = {
+  linux: {
+    x64: 'https://github.com/MetaCubeX/mihomo/releases/download/v1.18.7/mihomo-linux-amd64-compatible-v1.18.7.gz'
+  },
+  darwin: {
+    x64: 'https://github.com/MetaCubeX/mihomo/releases/download/v1.18.7/mihomo-darwin-amd64-v1.18.7.gz',
+    arm64: 'https://github.com/MetaCubeX/mihomo/releases/download/v1.18.7/mihomo-darwin-arm64-v1.18.7.gz'
+  }
+};
+
+const ensureMihomoBinary = async () => {
+  await fsp.mkdir(mihomoBinaryDir, { recursive: true });
+  if (!fs.existsSync(mihomoBinaryPath)) {
+    const writeStream = fs.createWriteStream(mihomoBinaryPath);
+
+    const downloadUrl = mihomoBinaryUrl[process.platform]?.[process.arch];
+    if (!downloadUrl) {
+      throw new Error(`Unsupported platform: ${process.platform} ${process.arch}`);
+    }
+
+    const res = await fetch(downloadUrl);
+
+    if (!res.ok || !res.body) {
+      throw new Error(`Failed to download mihomo binary: ${res.statusText}`);
+    }
+
+    const gunzip = zlib.createGunzip();
+
+    await pipeline(
+      Readable.fromWeb(res.body),
+      gunzip,
+      writeStream
+    );
+  }
+  await fsp.chmod(mihomoBinaryPath, 0o755);
+};
+
+export const convertClashMetaMrs = async (type: 'domain', format: 'text', input: string, output: string) => {
+  await ensureMihomoBinary();
+
+  const { stderr } = await ezspawn(mihomoBinaryPath, ['convert-ruleset', type, format, input, output]);
+
+  if (stderr) {
+    throw new Error(stderr);
+  }
+};