From f9724842cdb592a6ec0fcaf82ba25549338a5b99 Mon Sep 17 00:00:00 2001
From: zgrguric <zgrguric@xrplwin.com>
Date: Thu, 28 Mar 2024 16:02:43 +0100
Subject: [PATCH] [WIP] CurrencyConverter

---
 composer.json           |  3 +-
 phpunit.xml.dist        |  4 +--
 src/Utilities/Util.php  | 77 +++++++++++++++++++++++++++++++++++++++++
 tests/Unit/UtilTest.php | 32 +++++++++++++++++
 4 files changed, 113 insertions(+), 3 deletions(-)
 create mode 100644 src/Utilities/Util.php
 create mode 100644 tests/Unit/UtilTest.php

diff --git a/composer.json b/composer.json
index abc6fee..db29e67 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,8 @@
         "brick/math": "^0.10.2|^0.11"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.1"
+        "phpunit/phpunit": "^10.1",
+        "symfony/var-dumper": "^6.1"
     },
     "scripts": {
         "test": "./vendor/bin/phpunit --testdox"
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 213d863..7e823ce 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -2,8 +2,8 @@
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.2/phpunit.xsd" bootstrap="vendor/autoload.php" colors="true" stopOnFailure="true" failOnWarning="true" failOnRisky="true" failOnEmptyTestSuite="true" beStrictAboutOutputDuringTests="true" cacheDirectory=".phpunit.cache">
   <testsuites>
     <testsuite name="Test suite">
-      <directory suffix="Test.php">./tests/Unit</directory>
-      <directory suffix="Test.php">./tests/Feature</directory>
+      <directory suffix="UtilTest.php">./tests/Unit</directory>
+      <!--<directory suffix="Test.php">./tests/Feature</directory>-->
     </testsuite>
   </testsuites>
 </phpunit>
diff --git a/src/Utilities/Util.php b/src/Utilities/Util.php
new file mode 100644
index 0000000..8f09835
--- /dev/null
+++ b/src/Utilities/Util.php
@@ -0,0 +1,77 @@
+<?php declare(strict_types=1);
+
+namespace XRPLWin\XRPL\Utilities;
+
+/**
+ * Utilities
+ */
+final class Util
+{
+  /**
+  * Decode HEX currency to symbol.
+  * If already symbol returns that symbol (checked by length).
+  * Examples: USD,EUR,534F4C4F00000000000000000000000000000000,LP 031234...
+  * @see https://3v4l.org/Mp2Fu
+  * @return string
+  */
+  public static function currencyToSymbol($currencycode, $malformedUtf8ReturnString = '?') : string
+  {
+    if( \strlen($currencycode) == 40 )
+    {
+      if(\substr($currencycode,0,2) == '03') {
+        //AMM LP token, 03 + 19 bytes of sha512
+        return 'LP '.$currencycode;
+      }
+
+      if(\substr($currencycode,0,2) == '01') {
+        //demurrage, convert it to utf8 for display
+        
+        
+        //let bytes = Buffer.from(demurrageCode, "hex")
+        $bytes = \array_values(unpack("C*", \hex2bin($currencycode)));
+        //let code = String.fromCharCode(bytes[1]) + String.fromCharCode(bytes[2]) + String.fromCharCode(bytes[3]);
+        $code = \chr($bytes[1]).\chr($bytes[2]).\chr($bytes[3]); //OK
+        
+        //let interest_start = (bytes[4] << 24) + (bytes[5] << 16) + (bytes[6] <<  8) + (bytes[7]);
+        //$interest_start = (int)(($bytes[4] << 24) . ($bytes[5] << 16) . ($bytes[6] << 8) . $bytes[7]);
+        //let interest_period = ieee754Float.fromBytes(bytes.slice(8, 16));
+        $interest_period = self::ieee754FloatFromBytes(\array_slice($bytes,8,8));
+        dd($interest_period);
+        //const year_seconds = 31536000; // By convention, the XRP Ledger's interest/demurrage rules use a fixed number of seconds per year (31536000), which is not adjusted for leap days or leap seconds
+        $year_seconds = 31536000;
+        //let interest_after_year = precision(Math.pow(Math.E, (interest_start+year_seconds - interest_start) / interest_period), 14);
+        $interest_after_year = $year_seconds / $interest_period;
+        dd($interest_start,$interest_after_year);
+        return 'DE '.$currencycode;
+      }
+
+      $r = \trim(\hex2bin($currencycode));
+      $r = preg_replace('/[\x00-\x1F\x7F]/', '', $r); //remove first 32 ascii characters and \x7F https://en.wikipedia.org/wiki/Control_character
+
+      if((bool)preg_match( '|[^\x20-\x7E]|', $r )) {
+        //binary eg: 80474F4C44000000000000000000000000000000
+        return preg_replace('/[[:^print:]]/', '', $r);
+      }
+
+      if(preg_match('//u', $r)) //This will will return 0 (with no additional information) if an invalid string is given.
+        return $r;
+      return $malformedUtf8ReturnString; //malformed UTF-8 string
+    }
+    return $currencycode;
+  }
+
+  /**
+   * IEEE 754 floating-point.
+   *
+   * Supports single- or double-precision
+   */
+  public static function ieee754FloatFromBytes(array $bytes)
+  {
+    dd($bytes,pack('h', $bytes));
+    $data = unpack('f', pack('i', $bytes));
+    if($data === false)
+      throw new \Exception('Unable to extract ieee754FloatFromBytes');
+    return \array_values($data)[0];
+  }
+
+}
\ No newline at end of file
diff --git a/tests/Unit/UtilTest.php b/tests/Unit/UtilTest.php
new file mode 100644
index 0000000..6527543
--- /dev/null
+++ b/tests/Unit/UtilTest.php
@@ -0,0 +1,32 @@
+<?php declare(strict_types=1);
+
+namespace XRPLWin\XRPL\Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+use XRPLWin\XRPL\Utilities\Util;
+
+class XRPLParserUtilUtilTest extends TestCase
+{
+  public function testConvertCurrencyToSymbolDemurrage()
+  {
+    $this->assertEquals('XAU (-0.5% pa)',Util::currencyToSymbol('0158415500000000C1F76FF6ECB0BAC600000000'));
+    
+  }
+
+  public function testConvertCurrencyToSymbolISO()
+  {
+    $this->assertEquals('USD',Util::currencyToSymbol('USD'));
+    $this->assertEquals('EUR',Util::currencyToSymbol('EUR'));
+    $this->assertEquals('ABC',Util::currencyToSymbol('ABC'));
+    $this->assertEquals('000',Util::currencyToSymbol('000'));
+    $this->assertEquals('AB0',Util::currencyToSymbol('AB0'));
+    $this->assertEquals('123',Util::currencyToSymbol('123'));
+  }
+
+  public function testConvertCurrencyToSymbolLP()
+  {
+    $this->assertEquals('LP 03B20F3A7D26D33C6DA3503E5CCE3E67B102D4D2',Util::currencyToSymbol('03B20F3A7D26D33C6DA3503E5CCE3E67B102D4D2'));
+  }
+
+  
+}
\ No newline at end of file