Updated system to obfuscate IP addresses before persisting them

module/Common/src/Util/IpAddress.php

@@ -0,0 +1,74 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Common\Util;
+
+use Shlinkio\Shlink\Common\Exception\WrongIpException;
+
+final class IpAddress
+{
+    private const IPV4_PARTS_COUNT = 4;
+    private const OBFUSCATED_OCTET = '0';
+    public const LOCALHOST = '127.0.0.1';
+
+    /**
+     * @var string
+     */
+    private $firstOctet;
+    /**
+     * @var string
+     */
+    private $secondOctet;
+    /**
+     * @var string
+     */
+    private $thirdOctet;
+    /**
+     * @var string
+     */
+    private $fourthOctet;
+    /**
+     * @var bool
+     */
+    private $isLocalhost;
+
+    private function __construct()
+    {
+    }
+
+    /**
+     * @param string $address
+     * @return IpAddress
+     * @throws WrongIpException
+     */
+    public static function fromString(string $address): self
+    {
+        $address = \trim($address);
+        $parts = \explode('.', $address);
+        if (\count($parts) !== self::IPV4_PARTS_COUNT) {
+            throw WrongIpException::fromIpAddress($address);
+        }
+
+        $instance = new self();
+        $instance->isLocalhost = $address === self::LOCALHOST;
+        [$instance->firstOctet, $instance->secondOctet, $instance->thirdOctet, $instance->fourthOctet] = $parts;
+        return $instance;
+    }
+
+    public function getObfuscatedCopy(): self
+    {
+        $copy = clone $this;
+        $copy->fourthOctet = $this->isLocalhost ? $this->fourthOctet : self::OBFUSCATED_OCTET;
+        return $copy;
+    }
+
+    public function __toString(): string
+    {
+        return \implode('.', [
+            $this->firstOctet,
+            $this->secondOctet,
+            $this->thirdOctet,
+            $this->fourthOctet,
+        ]);
+    }
+}