Add encrypted Etsy app credential settings

app/Http/Controllers/EtsySettingsController.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\EtsyAppCredential;
+use App\Models\EtsyConnection;
+use App\Services\Etsy;
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Illuminate\View\View;
+
+class EtsySettingsController extends Controller
+{
+    public function index(Request $request, Etsy $etsy): View
+    {
+        abort_unless($request->user()->role === 'admin', 403);
+
+        return view('settings.index', [
+            'storedCredentials' => EtsyAppCredential::find(1) !== null,
+            'configured' => $etsy->configured(),
+            'redirectUri' => $etsy->redirectUri(),
+        ]);
+    }
+
+    public function update(Request $request): RedirectResponse
+    {
+        abort_unless($request->user()->role === 'admin', 403);
+
+        $credentials = EtsyAppCredential::find(1);
+        $requireCredentials = $credentials === null ? 'required' : 'nullable';
+        $validated = $request->validate([
+            'keystring' => [$requireCredentials, 'string', 'max:255'],
+            'shared_secret' => [$requireCredentials, 'string', 'max:255'],
+        ]);
+
+        $previousKeystring = $credentials?->keystring ?: config('services.etsy.keystring');
+        $credentials ??= new EtsyAppCredential;
+        $credentials->id = 1;
+        $credentials->fill(array_filter($validated, fn (?string $value): bool => filled($value)));
+        $credentials->save();
+
+        $keystringChanged = $previousKeystring !== $credentials->keystring;
+        if ($keystringChanged) {
+            EtsyConnection::query()->delete();
+        }
+
+        return redirect()->route('settings.index')->with('status', $keystringChanged
+            ? 'Etsy credentials saved. Reconnect your shop with the new app key.'
+            : 'Etsy credentials saved.');
+    }
+}