add contraint , that everybody expect admin is limited to 3 days, Add card package

common/components/FreeUniqueCardNumberGenerator.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace common\components;
+
+use common\models\Card;
+
+class FreeUniqueCardNumberGenerator extends \yii\base\Object {
+	public $count;
+	public $keyset = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
+	public $length = 6;
+	public $cache = [ ];
+	public $prefix = "";
+	public function generate() {
+		if ($this->count == 0) {
+			return;
+		}
+		
+		for($i = 0; $i < $this->count; $i ++) {
+			
+			$unique = false;
+			$number = null;
+			while ( $unique == false ) {
+				$number = Helper::generateRandomString($this->length, $this->keyset);
+				$number = $this->prefix . $number;
+				$unique = $this->checkCacheUnique ( $number ) && $this->checkDBUniqu ( $number );
+			}
+			$this->cache [] = $number;
+		}
+	}
+	protected function checkDBUniqu($number) {
+		$query = Card::find ();
+		Card::addCardNumberCondition ( $query, $number );
+		$found = $query->all ();
+		$result = count ( $found ) == 0;
+		return $result;
+	}
+	protected function checkCacheUnique($number) {
+		return array_search ( $number, $this->cache ) === false;
+	}
+}