Add frontend git update button and backend update endpoint

Dockerfile

@@ -2,6 +2,8 @@ FROM node:20-alpine
 
 WORKDIR /app
 
+RUN apk add --no-cache git
+
 COPY package*.json ./
 RUN npm install --omit=dev
 

README.md

@@ -8,6 +8,8 @@ Web-Frontend, um Alben aus Spotify zu suchen und an Lidarr zu uebergeben.
 - Track-Auswahl pro Album
 - Uebergabe an Lidarr als Album-Download (MissingAlbumSearch)
 - Einstellung im Frontend: ueberfluessige Dateien nach Download loeschen (optional)
+- Button fuer Lidarr Bibliothek-Update
+- Button fuer Frontend Git-Update (fetch/pull)
 - Docker-ready
 
 ## Voraussetzungen

public/app.js

@@ -10,6 +10,7 @@ const trackList = document.getElementById('trackList');
 const sendBtn = document.getElementById('sendBtn');
 const cleanupToggle = document.getElementById('cleanupToggle');
 const updateLibraryBtn = document.getElementById('updateLibraryBtn');
+const updateFrontendBtn = document.getElementById('updateFrontendBtn');
 
 let selectedAlbum = null;
 
@@ -239,6 +240,29 @@ async function updateLibrary() {
   }
 }
 
+async function updateFrontendFromGit() {
+  setStatus('Hole aktuelle Git-Daten...');
+  updateFrontendBtn.disabled = true;
+
+  try {
+    const data = await fetchJson('/api/system/update-frontend', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' }
+    });
+
+    if (data.updated) {
+      setStatus(`Frontend aktualisiert (${data.before} -> ${data.after}). Seite wird neu geladen...`);
+      setTimeout(() => window.location.reload(), 1200);
+    } else {
+      setStatus(`Bereits aktuell (${data.after}).`);
+    }
+  } catch (err) {
+    setStatus(`Frontend-Update fehlgeschlagen: ${err.message}`, true);
+  } finally {
+    updateFrontendBtn.disabled = false;
+  }
+}
+
 searchBtn.addEventListener('click', searchSpotify);
 queryInput.addEventListener('keydown', (event) => {
   if (event.key === 'Enter') {
@@ -247,3 +271,4 @@ queryInput.addEventListener('keydown', (event) => {
 });
 sendBtn.addEventListener('click', sendToLidarr);
 updateLibraryBtn.addEventListener('click', updateLibrary);
+updateFrontendBtn.addEventListener('click', updateFrontendFromGit);

public/index.html

@@ -24,6 +24,7 @@
         </label>
         <div style="margin-top: 0.8rem;">
           <button id="updateLibraryBtn" type="button">Lidarr Bibliothek updaten</button>
+          <button id="updateFrontendBtn" type="button">Frontend updaten</button>
         </div>
         <p class="hint">
           Wenn nur einzelne Songs gewaehlt sind, versucht die App unnoetige Track-Dateien in Lidarr zu entfernen.

server.js

@@ -2,9 +2,12 @@ require('dotenv').config();
 const express = require('express');
 const path = require('path');
 const axios = require('axios');
+const { execFile } = require('child_process');
+const { promisify } = require('util');
 
 const app = express();
 const port = Number(process.env.PORT || 3000);
+const execFileAsync = promisify(execFile);
 
 const lidarrUrl = (process.env.LIDARR_URL || '').replace(/\/$/, '');
 const lidarrApiKey = process.env.LIDARR_API_KEY || '';
@@ -40,6 +43,39 @@ function lidarrHeaders() {
   };
 }
 
+async function runGit(args) {
+  const { stdout } = await execFileAsync('git', args, {
+    cwd: __dirname,
+    timeout: 20000
+  });
+  return String(stdout || '').trim();
+}
+
+async function updateFrontendFromGit() {
+  if (!require('fs').existsSync(path.join(__dirname, '.git'))) {
+    throw new Error('Kein Git-Repository im Container/Projektpfad gefunden.');
+  }
+
+  try {
+    await runGit(['--version']);
+  } catch (_err) {
+    throw new Error('git ist nicht installiert.');
+  }
+
+  const before = await runGit(['rev-parse', '--short', 'HEAD']);
+  const branch = await runGit(['rev-parse', '--abbrev-ref', 'HEAD']);
+  const dirty = await runGit(['status', '--porcelain']);
+  if (dirty) {
+    throw new Error('Lokale Aenderungen vorhanden. Update per Button ist blockiert.');
+  }
+
+  await runGit(['fetch', '--prune', 'origin']);
+  await runGit(['pull', '--ff-only', 'origin', branch]);
+
+  const after = await runGit(['rev-parse', '--short', 'HEAD']);
+  return { before, after, branch, updated: before !== after };
+}
+
 async function lidarrRequest(method, endpoint, data, params) {
   if (!hasLidarrConfig()) {
     throw new Error('Lidarr-Konfiguration unvollstaendig.');
@@ -451,6 +487,15 @@ app.post('/api/lidarr/update-library', async (_req, res) => {
   }
 });
 
+app.post('/api/system/update-frontend', async (_req, res) => {
+  try {
+    const result = await updateFrontendFromGit();
+    res.json({ success: true, ...result });
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
 app.get('*', (_req, res) => {
   res.sendFile(path.join(__dirname, 'public', 'index.html'));
 });