Add util makeMptID

Author: zgrguric

composer.json

@@ -26,7 +26,8 @@
     "require": {
         "php": "^8.1.0",
         "guzzlehttp/guzzle": "^7.4",
-        "brick/math": "^0.10.2|^0.11|^0.12"
+        "brick/math": "^0.10.2|^0.11|^0.12",
+        "hardcastle/xrpl_php": "^0.8|^0.9"
     },
     "require-dev": {
         "phpunit/phpunit": "^10.1",

src/Utilities/Util.php

@@ -113,4 +113,15 @@ public static function ieee754FloatFromBytes(array $bytes): float|null|bool
 
   }
 
+  /**
+   * Test: makeMptID(4369311,'rGepNyxjJbtN75Zb4fgkjQsnv3UUcbp45E') should output: 0042AB9FAB8A5036CE4DB80D47016F557F9BFC9523985BF1
+   * @return string
+   */
+  public static function makeMptID(int $sequence, string $issuer): string {
+    $sequence = pack('N', $sequence); // 'N' = unsigned long (32-bit big endian)
+    $codec = new \Hardcastle\XRPL_PHP\Core\RippleAddressCodec\AddressCodec();
+    $accountID = $codec->decodeAccountId($issuer)->toUtf8();
+    return \strtoupper(\bin2hex($sequence . $accountID)); //Return as hex string
+  }
+
 }

tests/Unit/UtilTest.php

@@ -37,4 +37,11 @@ public function testConvertCurrencyToSymbolLP()
   {
     $this->assertEquals('LP 03B20F3A7D26D33C6DA3503E5CCE3E67B102D4D2',Util::currencyToSymbol('03B20F3A7D26D33C6DA3503E5CCE3E67B102D4D2'));
   }
+
+  public function testMakeMptId() {
+    $sequence = 4369311;
+    $issuer = 'rGepNyxjJbtN75Zb4fgkjQsnv3UUcbp45E';
+    $this->assertEquals('0042AB9FAB8A5036CE4DB80D47016F557F9BFC9523985BF1',Util::makeMptID($sequence,$issuer));
+
+  }
 }