<?php
namespace W3TCL\Minify;
/**
 * Class Minify_YUICompressor
 * @package Minify
 */

/**
 * Compress Javascript/CSS using the YUI Compressor
 *
 * You must set $jarFile and $tempDir before calling the minify functions.
 * Also, depending on your shell's environment, you may need to specify
 * the full path to java in $javaExecutable or use putenv() to setup the
 * Java environment.
 *
 * <code>
 * Minify_YUICompressor::$jarFile = '/path/to/yuicompressor-2.4.6.jar';
 * Minify_YUICompressor::$tempDir = '/tmp';
 * $code = Minify_YUICompressor::minifyJs(
 *   $code
 *   ,array('nomunge' => true, 'line-break' => 1000)
 * );
 * </code>
 *
 * Note: In case you run out stack (default is 512k), you may increase stack size in $options:
 *   array('stack-size' => '2048k')
 *
 * @todo unit tests, $options docs
 *
 * @package Minify
 * @author Stephen Clay <steve@mrclay.org>
 */
class Minify_YUICompressor {

	/**
	 * Filepath of the YUI Compressor jar file. This must be set before
	 * calling minifyJs() or minifyCss().
	 *
	 * @var string
	 */
	public static $jarFile = null;

	/**
	 * Writable temp directory. This must be set before calling minifyJs()
	 * or minifyCss().
	 *
	 * @var string
	 */
	public static $tempDir = null;

	/**
	 * Filepath of "java" executable (may be needed if not in shell's PATH)
	 *
	 * @var string
	 */
	public static $javaExecutable = 'java';

	/**
	 * Minify a Javascript string
	 *
	 * @param string $js
	 *
	 * @param array $options (verbose is ignored)
	 *
	 * @see http://www.julienlecomte.net/yuicompressor/README
	 *
	 * @return string
	 */
	public static function minifyJs($js, $options = array())
	{
		return self::_minify('js', $js, $options);
	}

	/**
	 * Minify a CSS string
	 *
	 * @param string $css
	 *
	 * @param array $options (verbose is ignored)
	 *
	 * @see http://www.julienlecomte.net/yuicompressor/README
	 *
	 * @return string
	 */
	public static function minifyCss($css, $options = array())
	{
		$css = self::_minify('css', $css, $options);
		$css = Minify_CSS_UriRewriter::rewrite($css, $options);

		return $css;
	}

	private static function _minify($type, $content, $options)
	{
		self::_prepare();
		if (! ($tmpFile = tempnam(self::$tempDir, 'yuic_'))) {
			throw new \Exception('Minify_YUICompressor : could not create temp file.');
		}
		file_put_contents($tmpFile, $content);
		exec(self::_getCmd($options, $type, $tmpFile), $output, $result_code);
		unlink($tmpFile);
		if ($result_code != 0) {
			throw new \Exception('Minify_YUICompressor : YUI compressor execution failed.');
		}
		return implode("\n", $output);
	}

	private static function _getCmd($userOptions, $type, $tmpFile)
	{
		if (!is_file(self::$javaExecutable)) {
			throw new \Exception(sprintf('JAVA executable (%s) is not a valid file.', self::$javaExecutable));
		}

		if (!is_file(self::$jarFile)) {
			throw new \Exception(sprintf('JAR file (%s) is not a valid file.', self::$jarFile));
		}
		$o = array_merge(
			array(
				'charset' => ''
				,'line-break' => 5000
				,'type' => $type
				,'nomunge' => false
				,'preserve-semi' => false
				,'disable-optimizations' => false
				,'stack-size' => ''
			)
			,$userOptions
		);

		$javaExecutable = self::$javaExecutable;
		if ( false !== strpos(trim($javaExecutable), ' ') ) {
			 $javaExecutable = '"'. $javaExecutable . '"';
		}

		$cmd = $javaExecutable
			 . (!empty($o['stack-size'])
				? ' -Xss' . $o['stack-size']
				: '')
			 . ' -jar ' . escapeshellarg(self::$jarFile)
			 . " --type {$type}"
			 . (preg_match('/^[\\da-zA-Z0-9\\-]+$/', $o['charset'])
				? " --charset {$o['charset']}"
				: '')
			 . (is_numeric($o['line-break']) && $o['line-break'] >= 0
				? ' --line-break ' . (int)$o['line-break']
				: '');
		if ($type === 'js') {
			foreach (array('nomunge', 'preserve-semi', 'disable-optimizations') as $opt) {
				$cmd .= $o[$opt]
					? " --{$opt}"
					: '';
			}
		}
		return $cmd . ' ' . escapeshellarg($tmpFile);
	}

	private static function _prepare()
	{
		if (! is_file(self::$jarFile)) {
			throw new \Exception('Minify_YUICompressor : $jarFile('.self::$jarFile.') is not a valid file.');
		}
		if (! is_readable(self::$jarFile)) {
			throw new \Exception('Minify_YUICompressor : $jarFile('.self::$jarFile.') is not readable.');
		}
		if (! is_dir(self::$tempDir)) {
			throw new \Exception('Minify_YUICompressor : $tempDir('.self::$tempDir.') is not a valid direcotry.');
		}
		if (! is_writable(self::$tempDir)) {
			throw new \Exception('Minify_YUICompressor : $tempDir('.self::$tempDir.') is not writable.');
		}
	}

	public static function testJs(&$error) {
		try {
			Minify_YUICompressor::minifyJs('alert("ok");');
			$error = 'OK';

			return true;
		} catch (\Exception $exception) {
			$error = $exception->getMessage();

			return false;
		}
	}

	public static function testCss(&$error) {
		try {
			Minify_YUICompressor::minifyCss('p{color:red}');
			$error = 'OK';

			return true;
		} catch (\Exception $exception) {
			$error = $exception->getMessage();

			return false;
		}
	}
}
