tags creation added

app/Rules/TagUniqueRule.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Rules;
+
+use App\Models\Tag;
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+
+class TagUniqueRule implements ValidationRule
+{
+    /**
+     * Indicates whether the rule should be implicit.
+     *
+     * @var bool
+     */
+    public $implicit = true;
+
+    public function __construct(public string $type = 'library_item')
+    {
+    }
+
+    /**
+     * Run the validation rule.
+     *
+     * @param  \Closure(string): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     */
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        $tag = Tag::findFromString($value, $this->type);
+        if ($tag) {
+            $fail(__('Tags must be unique', ['attribute' => $attribute]));
+        }
+    }
+}