feature: dark theme: add (#332)

server/theme.mjs

@@ -0,0 +1,33 @@
+import path, {dirname} from 'node:path';
+import {fileURLToPath} from 'node:url';
+import process from 'node:process';
+import fs from 'node:fs';
+import fullstore from 'fullstore';
+import nanomemoizeDefault from 'nano-memoize';
+import readFilesSync from '@cloudcmd/read-files-sync';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const isMap = (a) => /\.map$/.test(a);
+const not = (fn) => (a) => !fn(a);
+
+const _isDev = fullstore(process.env.NODE_ENV === 'development');
+const getDist = (isDev) => isDev ? 'dist-dev' : 'dist';
+
+export const isDev = _isDev;
+
+export const getThemes = ({isDev = _isDev()} = {}) => {
+    return readFilesSyncMemo(isDev);
+};
+
+const {nanomemoize} = nanomemoizeDefault;
+
+const readFilesSyncMemo = nanomemoize((isDev) => {
+    const dist = getDist(isDev);
+    const themesDir = path.join(__dirname, '..', dist, 'themes');
+    const names = fs
+        .readdirSync(themesDir)
+        .filter(not(isMap));
+    
+    return readFilesSync(themesDir, names, 'utf8');
+});