<?php
/**
 * Class Minify_Source 
 * @package Minify
 */

/** 
 * A content source to be minified by Minify. 
 * 
 * This allows per-source minification options and the mixing of files with
 * content from other sources.
 * 
 * @package Minify
 * @author Stephen Clay <steve@mrclay.org>
 */
class Minify_Source {

 /**
 * @var int time of last modification
 */
 public $lastModified = null;
 
 /**
 * @var callback minifier function specifically for this source.
 */
 public $minifier = null;
 
 /**
 * @var array minification options specific to this source.
 */
 public $minifyOptions = null;

 /**
 * @var string full path of file
 */
 public $filepath = null;
 
 /**
 * @var string HTTP Content Type (Minify requires one of the constants Minify::TYPE_*)
 */
 public $contentType = null;
 
 /**
 * Create a Minify_Source
 * 
 * In the $spec array(), you can either provide a 'filepath' to an existing
 * file (existence will not be checked!) or give 'id' (unique string for 
 * the content), 'content' (the string content) and 'lastModified' 
 * (unixtime of last update).
 * 
 * As a shortcut, the controller will replace "//" at the beginning
 * of a filepath with $_SERVER['DOCUMENT_ROOT'] . '/'.
 *
 * @param array $spec options
 */
 public function __construct($spec)
 {
 if (isset($spec['filepath'])) {
 if (0 === strpos($spec['filepath'], '//')) {
 $spec['filepath'] = $_SERVER['DOCUMENT_ROOT'] . substr($spec['filepath'], 1);
 }
 $segments = explode('.', $spec['filepath']);
 $ext = strtolower(array_pop($segments));
 switch ($ext) {
 case 'js' : $this->contentType = 'application/x-javascript';
 break;
 case 'css' : $this->contentType = 'text/css';
 break;
 case 'htm' : // fallthrough
 case 'html' : $this->contentType = 'text/html';
 break;
 }
 $this->filepath = $spec['filepath'];
 $this->_id = $spec['filepath'];
 $this->lastModified = filemtime($spec['filepath'])
 // offset for Windows uploaders with out of sync clocks
 + round(Minify::$uploaderHoursBehind * 3600);
 } elseif (isset($spec['id'])) {
 $this->_id = 'id::' . $spec['id'];
 if (isset($spec['content'])) {
 $this->_content = $spec['content'];
 } else {
 $this->_getContentFunc = $spec['getContentFunc'];
 }
 $this->lastModified = isset($spec['lastModified'])
 ? $spec['lastModified']
 : time();
 }
 if (isset($spec['contentType'])) {
 $this->contentType = $spec['contentType'];
 }
 if (isset($spec['minifier'])) {
 $this->minifier = $spec['minifier'];
 }
 if (isset($spec['minifyOptions'])) {
 $this->minifyOptions = $spec['minifyOptions'];
 }
 }
 
 /**
 * Get content
 *
 * @return string
 */
 public function getContent()
 {
 $content = (null !== $this->filepath)
 ? file_get_contents($this->filepath)
 : ((null !== $this->_content)
 ? $this->_content
 : call_user_func($this->_getContentFunc, $this->_id)
 );
 // remove UTF-8 BOM if present
 return (pack("CCC",0xef,0xbb,0xbf) === substr($content, 0, 3))
 ? substr($content, 3)
 : $content;
 }
 
 /**
 * Get id
 *
 * @return string
 */
 public function getId()
 {
 return $this->_id;
 }
 
 /**
 * Verifies a single minification call can handle all sources
 *
 * @param array $sources Minify_Source instances
 * 
 * @return bool true iff there no sources with specific minifier preferences.
 */
 public static function haveNoMinifyPrefs($sources)
 {
 foreach ($sources as $source) {
 if (null !== $source->minifier
 || null !== $source->minifyOptions) {
 return false;
 }
 }
 return true;
 }
 
 /**
 * Get unique string for a set of sources
 *
 * @param array $sources Minify_Source instances
 * 
 * @return string
 */
 public static function getDigest($sources)
 {
 foreach ($sources as $source) {
 $info[] = array(
 $source->_id, $source->minifier, $source->minifyOptions
 );
 }
 return md5(serialize($info));
 }
 
 /**
 * Get content type from a group of sources
 * 
 * This is called if the user doesn't pass in a 'contentType' options 
 * 
 * @param array $sources Minify_Source instances
 * 
 * @return string content type. e.g. 'text/css'
 */
 public static function getContentType($sources)
 {
 foreach ($sources as $source) {
 if ($source->contentType !== null) {
 return $source->contentType;
 }
 }
 return 'text/plain';
 }
 
 protected $_content = null;
 protected $_getContentFunc = null;
 protected $_id = null;
}