PHP function for compress .css or .js files with a timestamp.

compressfiles.func.php

<?php
function compressFiles(array $files){
    $debug = false;
    $buffer = '';
    $firstFile = $files[0];

    if($debug === true){
        switch(pathinfo($firstFile)['extension']){
            case 'css':
            foreach ($files as $file) {
                if (!$ftime = filemtime($file)) {
                    return $file;
                }
                $outputTime = $file.'?time='.$ftime;
                echo '<link rel="stylesheet" type="text/css" href="' . $outputTime . '" media="screen">';
            }
            break;

            case 'js':
            foreach ($files as $file) {
                if (!$ftime = filemtime($file)) {
                    return $file;
                }
                $outputTime = $file.'?time='.$ftime;
                echo '<script src="' . $outputTime . '" type="text/javascript"></script>';
            }
            break;
        }
    }
    else {
        switch(pathinfo($firstFile)['extension']){
            case 'css':
            $outputFile = '../../assets/css/style.min.css';
            break;

            case 'js':
            $outputFile = '../../assets/js/script.min.js';
            break;
        }

        foreach ($files as $file) {
            $buffer .= file_get_contents($file);
        }

        // Remove comments
        $buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);

        // Remove space after colons
        $buffer = str_replace(': ', ':', $buffer);

        // Remove whitespace
        $buffer = str_replace(array("\r\n", "\r", "\n", "\t", '  ', '    ', '    '), '', $buffer);

        // Write everything out
        file_put_contents($outputFile, $buffer);

        if (!$ftime = filemtime($outputFile)) {
            return $outputFile;
        }

        $outputTime = $outputFile.'?time='.$ftime;

        switch(pathinfo($outputFile)['extension']){
            case 'css':
            echo '<link rel="stylesheet" type="text/css" href="' . $outputTime . '" media="screen">';
            break;

            case 'js':
            echo '<script src="' . $outputTime . '" type="text/javascript"></script>';
            break;
        }
    }
}