<?php
/**
 * jsmin.php - PHP implementation of Douglas Crockford's JSMin.
 *
 * This is pretty much a direct port of jsmin.c to PHP with just a few
 * PHP-specific performance tweaks. Also, whereas jsmin.c reads from stdin and
 * outputs to stdout, this library accepts a string as input and returns another
 * string as output.
 *
 * PHP 5 or higher is required.
 *
 * Permission is hereby granted to use this version of the library under the
 * same terms as jsmin.c, which has the following license:
 *
 * --
 * Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * The Software shall be used for Good, not Evil.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * --
 *
 * @package JSMin
 * @author Ryan Grove <ryan@wonko.com>
 * @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
 * @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
 * @license http://opensource.org/licenses/mit-license.php MIT License
 * @version 1.1.1 (2008-03-02)
 * @link http://code.google.com/p/jsmin-php/
 */

class JSMin {
  const ORD_LF    = 10;
  const ORD_SPACE = 32;

  protected $a           = '';
  protected $b           = '';
  protected $input       = '';
  protected $inputIndex  = 0;
  protected $inputLength = 0;
  protected $lookAhead   = null;
  protected $output      = '';

  // -- Public Static Methods --------------------------------------------------

  public static function minify($js) {
	$jsmin = new JSMin($js);
	return $jsmin->min();
  }

  // -- Public Instance Methods ------------------------------------------------

  public function __construct($input) {
	$this->input       = str_replace("\r\n", "\n", $input);
	$this->inputLength = strlen($this->input);
  }

  // -- Protected Instance Methods ---------------------------------------------

  protected function action($d) {
	switch($d) {
	  case 1:
		$this->output .= $this->a;

	  case 2:
		$this->a = $this->b;

		if ($this->a === "'" || $this->a === '"') {
		  for (;;) {
			$this->output .= $this->a;
			$this->a       = $this->get();

			if ($this->a === $this->b) {
			  break;
			}

			if (ord($this->a) <= self::ORD_LF) {
			  throw new JSMinException('Unterminated string literal.');
			}

			if ($this->a === '\\') {
			  $this->output .= $this->a;
			  $this->a       = $this->get();
			}
		  }
		}

	  case 3:
		$this->b = $this->next();

		if ($this->b === '/' && (
			$this->a === '(' || $this->a === ',' || $this->a === '=' ||
			$this->a === ':' || $this->a === '[' || $this->a === '!' ||
			$this->a === '&' || $this->a === '|' || $this->a === '?')) {

		  $this->output .= $this->a . $this->b;

		  for (;;) {
			$this->a = $this->get();

			if ($this->a === '/') {
			  break;
			} elseif ($this->a === '\\') {
			  $this->output .= $this->a;
			  $this->a       = $this->get();
			} elseif (ord($this->a) <= self::ORD_LF) {
			  throw new JSMinException('Unterminated regular expression '.
				  'literal.');
			}

			$this->output .= $this->a;
		  }

		  $this->b = $this->next();
		}
	}
  }

  protected function get() {
	$c = $this->lookAhead;
	$this->lookAhead = null;

	if ($c === null) {
	  if ($this->inputIndex < $this->inputLength) {
		$c = $this->input[$this->inputIndex];
		$this->inputIndex += 1;
	  } else {
		$c = null;
	  }
	}

	if ($c === "\r") {
	  return "\n";
	}

	if ($c === null || $c === "\n" || ord($c) >= self::ORD_SPACE) {
	  return $c;
	}

	return ' ';
  }

  protected function isAlphaNum($c) {
	return ord($c) > 126 || $c === '\\' || preg_match('/^[\w\$]$/', $c) === 1;
  }

  protected function min() {
	$this->a = "\n";
	$this->action(3);

	while ($this->a !== null) {
	  switch ($this->a) {
		case ' ':
		  if ($this->isAlphaNum($this->b)) {
			$this->action(1);
		  } else {
			$this->action(2);
		  }
		  break;

		case "\n":
		  switch ($this->b) {
			case '{':
			case '[':
			case '(':
			case '+':
			case '-':
			  $this->action(1);
			  break;

			case ' ':
			  $this->action(3);
			  break;

			default:
			  if ($this->isAlphaNum($this->b)) {
				$this->action(1);
			  }
			  else {
				$this->action(2);
			  }
		  }
		  break;

		default:
		  switch ($this->b) {
			case ' ':
			  if ($this->isAlphaNum($this->a)) {
				$this->action(1);
				break;
			  }

			  $this->action(3);
			  break;

			case "\n":
			  switch ($this->a) {
				case '}':
				case ']':
				case ')':
				case '+':
				case '-':
				case '"':
				case "'":
				  $this->action(1);
				  break;

				default:
				  if ($this->isAlphaNum($this->a)) {
					$this->action(1);
				  }
				  else {
					$this->action(3);
				  }
			  }
			  break;

			default:
			  $this->action(1);
			  break;
		  }
	  }
	}

	return $this->output;
  }

  protected function next() {
	$c = $this->get();

	if ($c === '/') {
	  switch($this->peek()) {
		case '/':
		  for (;;) {
			$c = $this->get();

			if (ord($c) <= self::ORD_LF) {
			  return $c;
			}
		  }

		case '*':
		  $this->get();

		  for (;;) {
			switch($this->get()) {
			  case '*':
				if ($this->peek() === '/') {
				  $this->get();
				  return ' ';
				}
				break;

			  case null:
				throw new JSMinException('Unterminated comment.');
			}
		  }

		default:
		  return $c;
	  }
	}

	return $c;
  }

  protected function peek() {
	$this->lookAhead = $this->get();
	return $this->lookAhead;
  }
}

// -- Exceptions ---------------------------------------------------------------
class JSMinException extends Exception {}
?>