Add theme installer and uninstall command for Hexo

lib/console/index.ts

@@ -1,6 +1,7 @@
 import type Context from '../context';
 import helpConsole from './help';
 import initConsole from './init';
+import themeConsole from './theme';
 import versionConsole from './version';
 
 export = function(ctx: Context) {
@@ -20,5 +21,14 @@ export = function(ctx: Context) {
     ]
   }, initConsole);
 
+  console.register('theme', 'Manage themes.', {
+    desc: 'Install and uninstall Hexo themes.',
+    usage: '<install|uninstall> <theme-name>',
+    commands: [
+      {name: 'install <theme-name>', desc: 'Install an official Hexo theme.'},
+      {name: 'uninstall <theme-name>', desc: 'Uninstall a Hexo theme.'}
+    ]
+  }, themeConsole);
+
   console.register('version', 'Display version information.', {}, versionConsole);
 };

lib/console/theme.ts

@@ -0,0 +1,171 @@
+import { copyFile, existsSync, mkdirs, rmdir, unlink } from 'hexo-fs';
+import spawn from 'hexo-util/dist/spawn';
+import { basename, join } from 'path';
+import { sync as commandExistsSync } from 'command-exists';
+import type Context from '../context';
+
+const REGISTRY_URL = 'https://api.github.com/repos/hexojs/site/contents/source/_data/themes';
+
+interface ThemeArgs {
+  _: string[];
+}
+
+interface ThemeRegistryResponse {
+  content: string;
+}
+
+interface RegistryResponse {
+  ok: boolean;
+  status: number;
+  json(): Promise<unknown>;
+}
+
+async function themeConsole(this: Context, args: ThemeArgs) {
+  const [command, themeName, ...extraArgs] = args._;
+
+  if ((command !== 'install' && command !== 'uninstall') || !themeName || extraArgs.length) {
+    throw new Error('Usage: hexo theme <install|uninstall> <theme-name>');
+  }
+
+  if (themeName !== basename(themeName) || themeName === '.' || themeName === '..') {
+    throw new Error('Theme name must not contain a path.');
+  }
+
+  if (command === 'uninstall') {
+    await uninstallTheme(this, themeName);
+    return;
+  }
+
+  const target = join(this.base_dir, 'themes', themeName);
+  if (existsSync(target)) {
+    throw new Error(`Theme directory already exists: ${target}`);
+  }
+
+  if (!commandExistsSync('git')) {
+    throw new Error('Git is required to install themes. Please install Git and try again.');
+  }
+
+  const repository = await getThemeRepository(themeName);
+  const themesDir = join(this.base_dir, 'themes');
+
+  await mkdirs(themesDir);
+  this.log.info('Installing theme %s', themeName);
+
+  try {
+    await spawn('git', ['clone', '--depth=1', '--quiet', repository, target], {
+      stdio: 'inherit'
+    });
+
+    await installThemeDependencies(this.base_dir, target);
+    await copyThemeConfig(this, themeName, target);
+  } catch (err) {
+    await removeThemeDirectory(target);
+    throw err;
+  }
+
+  this.log.info('Theme %s installed in %s', themeName, target);
+  this.log.info('Set `theme: %s` in _config.yml to use it.', themeName);
+}
+
+async function getThemeRepository(themeName: string) {
+  const response = await fetchThemeRegistry(themeName);
+
+  if (response.status === 404) {
+    throw new Error(`Theme "${themeName}" is not listed in the official Hexo theme registry.`);
+  }
+
+  if (!response.ok) {
+    throw new Error(`Failed to fetch the official Hexo theme registry (HTTP ${response.status}).`);
+  }
+
+  const payload = await response.json() as ThemeRegistryResponse;
+  const metadata = Buffer.from(payload.content, 'base64').toString('utf8');
+  const link = metadata.split(/\r?\n/u).find(line => line.startsWith('link:'))!;
+
+  return link.slice('link:'.length).trim();
+}
+
+async function fetchThemeRegistry(themeName: string): Promise<RegistryResponse> {
+  try {
+    // fetch is stable in supported Node.js versions, but eslint-plugin-n still marks it as experimental before Node 21.
+    // eslint-disable-next-line n/no-unsupported-features/node-builtins
+    return await fetch(`${REGISTRY_URL}/${encodeURIComponent(themeName)}.yml`, {
+      headers: {
+        Accept: 'application/vnd.github+json',
+        'User-Agent': 'hexo-cli'
+      }
+    });
+  } catch {
+    throw new Error('Failed to fetch the official Hexo theme registry.');
+  }
+}
+
+async function installThemeDependencies(baseDir: string, target: string) {
+  if (!existsSync(join(target, 'package.json'))) return;
+
+  const packageManager = findPackageManager(baseDir);
+  if (!commandExistsSync(packageManager)) {
+    throw new Error(`${packageManager} is required to install theme dependencies. Please install it and try again.`);
+  }
+
+  let args: string[];
+  if (packageManager === 'pnpm') {
+    args = ['install', '--prod'];
+  } else if (packageManager === 'yarn') {
+    args = ['install', '--production'];
+  } else {
+    args = ['install', '--omit=dev'];
+  }
+
+  await spawn(packageManager, args, {
+    cwd: target,
+    stdio: 'inherit'
+  });
+}
+
+async function copyThemeConfig(ctx: Context, themeName: string, target: string) {
+  const source = join(target, '_config.yml');
+  const destination = join(ctx.base_dir, `_config.${themeName}.yml`);
+
+  if (!existsSync(source)) {
+    ctx.log.warn('Theme %s does not provide _config.yml; no theme config was created.', themeName);
+    return;
+  }
+
+  if (existsSync(destination)) {
+    ctx.log.warn('Theme config already exists at %s; keeping the existing file.', destination);
+    return;
+  }
+
+  await copyFile(source, destination);
+  ctx.log.info('Theme config copied to %s', destination);
+}
+
+async function uninstallTheme(ctx: Context, themeName: string) {
+  const target = join(ctx.base_dir, 'themes', themeName);
+  const config = join(ctx.base_dir, `_config.${themeName}.yml`);
+  const hasTheme = existsSync(target);
+  const hasConfig = existsSync(config);
+
+  if (!hasTheme && !hasConfig) {
+    throw new Error(`Theme "${themeName}" is not installed.`);
+  }
+
+  if (hasTheme) await rmdir(target);
+  if (hasConfig) await unlink(config);
+
+  ctx.log.info('Theme %s uninstalled.', themeName);
+}
+
+function findPackageManager(baseDir: string) {
+  if (existsSync(join(baseDir, 'pnpm-lock.yaml'))) return 'pnpm';
+  if (existsSync(join(baseDir, 'yarn.lock'))) return 'yarn';
+  return 'npm';
+}
+
+async function removeThemeDirectory(target: string) {
+  if (!existsSync(target)) return;
+  await rmdir(target);
+}
+
+export = themeConsole;

lib/hexo.ts

@@ -11,6 +11,7 @@ import { camelCaseKeys } from 'hexo-util';
 import registerConsole from './console';
 import helpConsole from './console/help';
 import initConsole from './console/init';
+import themeConsole from './console/theme';
 import versionConsole from './console/version';
 
 class HexoNotFoundError extends Error {}
@@ -70,6 +71,7 @@ function entry(cwd = process.cwd(), args) {
 entry.console = {
   init: initConsole,
   help: helpConsole,
+  theme: themeConsole,
   version: versionConsole
 };