New numerical validation.

app/Rules/IsValidAmount.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace FireflyIII\Rules;
+
+use FireflyIII\Support\Validation\ValidatesAmountsTrait;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Support\Facades\Log;
+
+class IsValidAmount implements ValidationRule
+{
+    use ValidatesAmountsTrait;
+
+    /**
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function validate(string $attribute, mixed $value, \Closure $fail): void
+    {
+        $value = (string)$value;
+
+        // must not be empty:
+        if($this->emptyString($value)) {
+            $fail('validation.filled')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" cannot be empty.', $value));
+            return;
+        }
+
+        // must be a number:
+        if(!$this->isValidNumber($value)) {
+            $fail('validation.numeric')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" is not a number.', $value));
+            return;
+        }
+
+        // must not be scientific notation:
+        if($this->scientificNumber($value)) {
+            $fail('validation.scientific_notation')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" cannot be in the scientific notation.', $value));
+            return;
+        }
+
+        // must be more than minus a lots:
+        if($this->lessThanLots($value)) {
+            $amount = bcmul('-1', self::BIG_AMOUNT);
+            $fail('validation.gte.numeric')->translate(['value' => $amount]);
+            Log::debug(sprintf('IsValidAmount: "%s" must be more than %s.', $value, $amount));
+            return;
+        }
+
+        // must be less than 100 million and 1709:
+        if($this->moreThanLots($value)) {
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" must be more than %s.', $value, self::BIG_AMOUNT));
+            $fail('validation.lte.numeric')->translate(['value' => self::BIG_AMOUNT]);
+        }
+        Log::debug(sprintf('IsValidAmount: "%s" is a valid positive amount.', $value));
+    }
+}