From 456177bdee4fb7690773ef1aa995bb9737573d1b Mon Sep 17 00:00:00 2001
From: Aaron <aschulz@wikimedia.org>
Date: Fri, 11 May 2012 10:53:14 -0700
Subject: [PATCH] [IP] Added an IP::prettifyIP() function for displaying IPs.

Change-Id: I53b3fe70bd0091ef02740f2b8950c36a0e4cf32e
---
 includes/IP.php                   | 45 ++++++++++++++++++++++++++++++-
 tests/phpunit/includes/IPTest.php | 34 +++++++++++++++++++++++
 2 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/includes/IP.php b/includes/IP.php
index e1c1f6d0a6..1828249889 100644
--- a/includes/IP.php
+++ b/includes/IP.php
@@ -133,7 +133,7 @@ class IP {
 	}
 
 	/**
-	 * Convert an IP into a nice standard form.
+	 * Convert an IP into a verbose, uppercase, normalized form.
 	 * IPv6 addresses in octet notation are expanded to 8 words.
 	 * IPv4 addresses are just trimmed.
 	 *
@@ -185,6 +185,49 @@ class IP {
 		return $ip;
 	}
 
+	/**
+	 * Prettify an IP for display to end users.
+	 * This will make it more compact and lower-case.
+	 *
+	 * @param $ip string
+	 * @return string
+	 */
+	public static function prettifyIP( $ip ) {
+		$ip = self::sanitizeIP( $ip ); // normalize (removes '::')
+		if ( self::isIPv6( $ip ) ) {
+			// Split IP into an address and a CIDR
+			if ( strpos( $ip, '/' ) !== false ) {
+				list( $ip, $cidr ) = explode( '/', $ip, 2 );
+			} else {
+				list( $ip, $cidr ) = array( $ip, '' );
+			}
+			// Get the largest slice of words with multiple zeros
+			$offset = 0;
+			$longest = $longestPos = false;
+			while ( preg_match(
+				'!(?:^|:)0(?::0)+(?:$|:)!', $ip, $m, PREG_OFFSET_CAPTURE, $offset
+			) ) {
+				list( $match, $pos ) = $m[0]; // full match
+				if ( strlen( $match ) > strlen( $longest ) ) {
+					$longest = $match;
+					$longestPos = $pos;
+				}
+				$offset += ( $pos + strlen( $match ) ); // advance
+			}
+			if ( $longest !== false ) {
+				// Replace this portion of the string with the '::' abbreviation
+				$ip = substr_replace( $ip, '::', $longestPos, strlen( $longest ) );
+			}
+			// Add any CIDR back on
+			if ( $cidr !== '' ) {
+				$ip = "{$ip}/{$cidr}";
+			}
+			// Convert to lower case to make it more readable
+			$ip = strtolower( $ip );
+		}
+		return $ip;
+	}
+
 	/**
 	 * Given a host/port string, like one might find in the host part of a URL
 	 * per RFC 2732, split the hostname part and the port part and return an
diff --git a/tests/phpunit/includes/IPTest.php b/tests/phpunit/includes/IPTest.php
index e38fa7e43c..f50b2fe9be 100644
--- a/tests/phpunit/includes/IPTest.php
+++ b/tests/phpunit/includes/IPTest.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * Tests for IP validity functions. Ported from /t/inc/IP.t by avar.
+ * @group IP
  */
 
 class IPTest extends MediaWikiTestCase {
@@ -505,4 +506,37 @@ class IPTest extends MediaWikiTestCase {
 			array( '0:c1:A2:3:4:5:c6:7', '0:C1:A2:3:4:5:C6:7', 'IPv6 non range' ),
 		);
 	}
+
+	/**
+	 * Test for IP::prettifyIP()
+	 * @dataProvider provideIPsToPrettify
+	 */
+	function testPrettifyIP( $ip, $prettified ) {
+		$this->assertEquals( $prettified, IP::prettifyIP( $ip ), "Prettify of $ip" );
+	}
+
+	/**
+	 * Provider for IP::testPrettifyIP()
+	 */
+	function provideIPsToPrettify() {
+		return array(
+			array( '0:0:0:0:0:0:0:0', '::' ),
+			array( '0:0:0::0:0:0', '::' ),
+			array( '0:0:0:1:0:0:0:0', '0:0:0:1::' ),
+			array( '0:0::f', '::f' ),
+			array( '0::0:0:0:33:fef:b', '::33:fef:b' ),
+			array( '3f:535:0:0:0:0:e:fbb', '3f:535::e:fbb' ),
+			array( '0:0:fef:0:0:0:e:fbb', '0:0:fef::e:fbb' ),
+			array( 'abbc:2004::0:0:0:0', 'abbc:2004::' ),
+			array( 'cebc:2004:f:0:0:0:0:0', 'cebc:2004:f::' ),
+			array( '0:0:0:0:0:0:0:0/16', '::/16' ),
+			array( '0:0:0::0:0:0/64', '::/64' ),
+			array( '0:0::f/52', '::f/52' ),
+			array( '::0:0:33:fef:b/52', '::33:fef:b/52' ),
+			array( '3f:535:0:0:0:0:e:fbb/48', '3f:535::e:fbb/48' ),
+			array( '0:0:fef:0:0:0:e:fbb/96', '0:0:fef::e:fbb/96' ),
+			array( 'abbc:2004:0:0::0:0/40', 'abbc:2004::/40' ),
+			array( 'aebc:2004:f:0:0:0:0:0/80', 'aebc:2004:f::/80' ),
+		);
+	}
 }
-- 
2.20.1