Automatically generate changelogs for CakePHP

changelog-cakephp.php

<?php
$options = array(
	'repo' => '/Users/predominant/Projects/cakephp/2.0/.git',
	'titleOrder' => array(
		'dev', 'alpha', 'beta', 'rc',
	),
	'regex' => '/(?<version>[\d\.]+)(?:-(?<title>[a-zA-Z]+)(?:(?<iteration>\d)?))?/',
	'formats' => array(
		'plaintext'  => '| awk \'{print "Commit: ["$1"]\n"; $1=""; print "-"$0"\n"}\'',
		'lighthouse' => '| awk \'{print "#### Commit: ["$1"](http://github.com/cakephp/cakephp/commit/"$1")\n"; $1=""; print $0"\n"}\'',
		'compact-md' => '| awk \'{print "* [Commit "$1"](http://github.com/cakephp/cakephp/commit/"$1"): "; $1=""; print $0}\'',
	),
);
$options['git-dir'] = '--git-dir=' . $options['repo'];
$options['format'] = !empty($_GET['format']) && array_key_exists($_GET['format'], $options['formats']) ? $_GET['format'] : 'plaintext';

$tags = explode("\n", trim(`git ${options['git-dir']} tag`));

usort($tags, function($from, $to) use ($options) {
	preg_match($options['regex'], $from, $fromMatches);
	preg_match($options['regex'], $to, $toMatches);
	
	$version = version_compare($fromMatches['version'], $toMatches['version']);
	if ($version !== 0) {
		return $version;
	}
	
	if (!isset($fromMatches['title'])) {
		return 1;
	}
	if (!isset($toMatches['title'])) {
		return -1;
	}

	$title = array_search(strtolower($fromMatches['title']), $options['titleOrder']) - array_search(strtolower($toMatches['title']), $options['titleOrder']);
	if ($title !== 0) {
		return $title;
	}
	
	return version_compare($fromMatches['iteration'], $toMatches['iteration']);
});
$tags = array_reverse($tags);

$previous = null;
echo '<h2>Format: ' . $options['format'] . '</h2>';
$format = $options['formats'][$options['format']];
foreach ($tags as $tag) {
	if (!$previous) {
		$previous = $tag;
		continue;
	}
	echo '<h3>Version ' . $tag . '</h3>';
	echo '<pre>' . htmlentities(`git ${options['git-dir']} rev-list --no-merges --oneline ${previous} ^${tag} ${format}`) . '</pre>';
	$previous = $tag;
}

make sense i'm going to test this on a current app i have with a bunch of a tags and various branches. thanks for the feedback though