feat: support action expression parsing, validation, and evaluation

app/Api/V1/Controllers/Models/Rule/ExpressionController.php

@@ -0,0 +1,89 @@
+<?php
+/*
+ * ExpressionController.php
+ * Copyright (c) 2024 Michael Thomas
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace FireflyIII\Api\V1\Controllers\Models\Rule;
+
+use FireflyIII\Api\V1\Controllers\Controller;
+use FireflyIII\Api\V1\Requests\Models\Rule\ValidateExpressionRequest;
+use FireflyIII\Repositories\Rule\RuleRepositoryInterface;
+use FireflyIII\TransactionRules\Expressions\ActionExpressionEvaluator;
+use FireflyIII\TransactionRules\Factory\ExpressionLanguageFactory;
+use FireflyIII\User;
+use Illuminate\Http\JsonResponse;
+use Symfony\Component\ExpressionLanguage\SyntaxError;
+
+/**
+ * Class ExpressionController
+ */
+class ExpressionController extends Controller
+{
+    private RuleRepositoryInterface $ruleRepository;
+
+    /**
+     * RuleController constructor.
+     *
+
+     */
+    public function __construct()
+    {
+        parent::__construct();
+        $this->middleware(
+            function ($request, $next) {
+                /** @var User $user */
+                $user = auth()->user();
+
+                $this->ruleRepository = app(RuleRepositoryInterface::class);
+                $this->ruleRepository->setUser($user);
+
+                return $next($request);
+            }
+        );
+    }
+
+    /**
+     * This endpoint is documented at:
+     * https://api-docs.firefly-iii.org/?urls.primaryName=2.0.0%20(v1)#/rules/validateExpression
+     *
+     * @param ValidateExpressionRequest $request
+     *
+     * @return JsonResponse
+     */
+    public function validateExpression(ValidateExpressionRequest $request): JsonResponse
+    {
+        $expr = $request->getExpression();
+        $expressionLanguage = ExpressionLanguageFactory::get();
+        $evaluator = new ActionExpressionEvaluator($expressionLanguage, $expr);
+
+        try {
+            $evaluator->lint();
+            return response()->json([
+                "valid" => true,
+            ]);
+        } catch (SyntaxError $e) {
+            return response()->json([
+                "valid" => false,
+                "error" => $e->getMessage()
+            ]);
+        }
+    }
+}