<?php

/**
 * This is a slightly modified version of github.com/markjaquith/WordPress-Plugin-Readme-Parser
 * It uses Parsedown instead of the "Markdown Extra" parser.
 */

Class PucReadmeParser {

	function __construct() {
		// This space intentially blank
	}

	function parse_readme( $file ) {
		$file_contents = @implode('', @file($file));
		return $this->parse_readme_contents( $file_contents );
	}

	function parse_readme_contents( $file_contents ) {
		$file_contents = str_replace(array("\r\n", "\r"), "\n", $file_contents);
		$file_contents = trim($file_contents);
		if ( 0 === strpos( $file_contents, "\xEF\xBB\xBF" ) )
			$file_contents = substr( $file_contents, 3 );

		// Markdown transformations
		$file_contents = preg_replace( "|^###([^#]+)#*?\s*?\n|im", '=$1='."\n",     $file_contents );
		$file_contents = preg_replace( "|^##([^#]+)#*?\s*?\n|im",  '==$1=='."\n",   $file_contents );
		$file_contents = preg_replace( "|^#([^#]+)#*?\s*?\n|im",   '===$1==='."\n", $file_contents );

		// === Plugin Name ===
		// Must be the very first thing.
		if ( !preg_match('|^===(.*)===|', $file_contents, $_name) )
			return array(); // require a name
		$name = trim($_name[1], '=');
		$name = $this->sanitize_text( $name );

		$file_contents = $this->chop_string( $file_contents, $_name[0] );


		// Requires at least: 1.5
		if ( preg_match('|Requires at least:(.*)|i', $file_contents, $_requires_at_least) )
			$requires_at_least = $this->sanitize_text($_requires_at_least[1]);
		else
			$requires_at_least = NULL;


		// Tested up to: 2.1
		if ( preg_match('|Tested up to:(.*)|i', $file_contents, $_tested_up_to) )
			$tested_up_to = $this->sanitize_text( $_tested_up_to[1] );
		else
			$tested_up_to = NULL;


		// Stable tag: 10.4-ride-the-fire-eagle-danger-day
		if ( preg_match('|Stable tag:(.*)|i', $file_contents, $_stable_tag) )
			$stable_tag = $this->sanitize_text( $_stable_tag[1] );
		else
			$stable_tag = NULL; // we assume trunk, but don't set it here to tell the difference between specified trunk and default trunk


		// Tags: some tag, another tag, we like tags
		if ( preg_match('|Tags:(.*)|i', $file_contents, $_tags) ) {
			$tags = preg_split('|,[\s]*?|', trim($_tags[1]));
			foreach ( array_keys($tags) as $t )
				$tags[$t] = $this->sanitize_text( $tags[$t] );
		} else {
			$tags = array();
		}


		// Contributors: markjaquith, mdawaffe, zefrank
		$contributors = array();
		if ( preg_match('|Contributors:(.*)|i', $file_contents, $_contributors) ) {
			$temp_contributors = preg_split('|,[\s]*|', trim($_contributors[1]));
			foreach ( array_keys($temp_contributors) as $c ) {
				$tmp_sanitized = $this->user_sanitize( $temp_contributors[$c] );
				if ( strlen(trim($tmp_sanitized)) > 0 )
					$contributors[$c] = $tmp_sanitized;
				unset($tmp_sanitized);
			}
		}


		// Donate Link: URL
		if ( preg_match('|Donate link:(.*)|i', $file_contents, $_donate_link) )
			$donate_link = esc_url( $_donate_link[1] );
		else
			$donate_link = NULL;


		// togs, conts, etc are optional and order shouldn't matter.  So we chop them only after we've grabbed their values.
		foreach ( array('tags', 'contributors', 'requires_at_least', 'tested_up_to', 'stable_tag', 'donate_link') as $chop ) {
			if ( $$chop ) {
				$_chop = '_' . $chop;
				$file_contents = $this->chop_string( $file_contents, ${$_chop}[0] );
			}
		}

		$file_contents = trim($file_contents);


		// short-description fu
		if ( !preg_match('/(^(.*?))^[\s]*=+?[\s]*.+?[\s]*=+?/ms', $file_contents, $_short_description) )
			$_short_description = array( 1 => &$file_contents, 2 => &$file_contents );
		$short_desc_filtered = $this->sanitize_text( $_short_description[2] );
		$short_desc_length = strlen($short_desc_filtered);
		$short_description = substr($short_desc_filtered, 0, 150);
		if ( $short_desc_length > strlen($short_description) )
			$truncated = true;
		else
			$truncated = false;
		if ( $_short_description[1] )
			$file_contents = $this->chop_string( $file_contents, $_short_description[1] ); // yes, the [1] is intentional

		// == Section ==
		// Break into sections
		// $_sections[0] will be the title of the first section, $_sections[1] will be the content of the first section
		// the array alternates from there:  title2, content2, title3, content3... and so forth
		$_sections = preg_split('/^[\s]*==[\s]*(.+?)[\s]*==/m', $file_contents, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY);

		$sections = array();
		for ( $i=1; $i <= count($_sections); $i +=2 ) {
			$_sections[$i] = preg_replace('/^[\s]*=[\s]+(.+?)[\s]+=/m', '<h4>$1</h4>', $_sections[$i]);
			$_sections[$i] = $this->filter_text( $_sections[$i], true );
			$title = $this->sanitize_text( $_sections[$i-1] );
			$sections[str_replace(' ', '_', strtolower($title))] = array('title' => $title, 'content' => $_sections[$i]);
		}


		// Special sections
		// This is where we nab our special sections, so we can enforce their order and treat them differently, if needed
		// upgrade_notice is not a section, but parse it like it is for now
		$final_sections = array();
		foreach ( array('description', 'installation', 'frequently_asked_questions', 'screenshots', 'changelog', 'change_log', 'upgrade_notice') as $special_section ) {
			if ( isset($sections[$special_section]) ) {
				$final_sections[$special_section] = $sections[$special_section]['content'];
				unset($sections[$special_section]);
			}
		}
		if ( isset($final_sections['change_log']) && empty($final_sections['changelog']) )
			$final_sections['changelog'] = $final_sections['change_log'];


		$final_screenshots = array();
		if ( isset($final_sections['screenshots']) ) {
			preg_match_all('|<li>(.*?)</li>|s', $final_sections['screenshots'], $screenshots, PREG_SET_ORDER);
			if ( $screenshots ) {
				foreach ( (array) $screenshots as $ss )
					$final_screenshots[] = $ss[1];
			}
		}

		// Parse the upgrade_notice section specially:
		// 1.0 => blah, 1.1 => fnord
		$upgrade_notice = array();
		if ( isset($final_sections['upgrade_notice']) ) {
			$split = preg_split( '#<h4>(.*?)</h4>#', $final_sections['upgrade_notice'], -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
			for ( $i = 0; $i < count( $split ); $i += 2 )
				$upgrade_notice[$this->sanitize_text( $split[$i] )] = substr( $this->sanitize_text( $split[$i + 1] ), 0, 300 );
			unset( $final_sections['upgrade_notice'] );
		}

		// No description?
		// No problem... we'll just fall back to the old style of description
		// We'll even let you use markup this time!
		$excerpt = false;
		if ( !isset($final_sections['description']) ) {
			$final_sections = array_merge(array('description' => $this->filter_text( $_short_description[2], true )), $final_sections);
			$excerpt = true;
		}


		// dump the non-special sections into $remaining_content
		// their order will be determined by their original order in the readme.txt
		$remaining_content = '';
		foreach ( $sections as $s_name => $s_data ) {
			$remaining_content .= "\n<h3>{$s_data['title']}</h3>\n{$s_data['content']}";
		}
		$remaining_content = trim($remaining_content);


		// All done!
		// $r['tags'] and $r['contributors'] are simple arrays
		// $r['sections'] is an array with named elements
		$r = array(
			'name' => $name,
			'tags' => $tags,
			'requires_at_least' => $requires_at_least,
			'tested_up_to' => $tested_up_to,
			'stable_tag' => $stable_tag,
			'contributors' => $contributors,
			'donate_link' => $donate_link,
			'short_description' => $short_description,
			'screenshots' => $final_screenshots,
			'is_excerpt' => $excerpt,
			'is_truncated' => $truncated,
			'sections' => $final_sections,
			'remaining_content' => $remaining_content,
			'upgrade_notice' => $upgrade_notice
		);

		return $r;
	}

	function chop_string( $string, $chop ) { // chop a "prefix" from a string: Agressive! uses strstr not 0 === strpos
		if ( $_string = strstr($string, $chop) ) {
			$_string = substr($_string, strlen($chop));
			return trim($_string);
		} else {
			return trim($string);
		}
	}

	function user_sanitize( $text, $strict = false ) { // whitelisted chars
		if ( function_exists('user_sanitize') ) // bbPress native
			return user_sanitize( $text, $strict );

		if ( $strict ) {
			$text = preg_replace('/[^a-z0-9-]/i', '', $text);
			$text = preg_replace('|-+|', '-', $text);
		} else {
			$text = preg_replace('/[^a-z0-9_-]/i', '', $text);
		}
		return $text;
	}

	function sanitize_text( $text ) { // not fancy
		$text = strip_tags($text);
		$text = esc_html($text);
		$text = trim($text);
		return $text;
	}

	function filter_text( $text, $markdown = false ) { // fancy, Markdown
		$text = trim($text);

		$text = call_user_func( array( __CLASS__, 'code_trick' ), $text, $markdown ); // A better parser than Markdown's for: backticks -> CODE

		if ( $markdown ) { // Parse markdown.
			if ( !class_exists('Parsedown', false) ) {
				require_once(dirname(__FILE__) . '/Parsedown' . (version_compare(PHP_VERSION, '5.3.0', '>=') ? '' : 'Legacy') . '.php');
			}
			$instance = Parsedown::instance();
			$text = $instance->text($text);
		}

		$allowed = array(
			'a' => array(
				'href' => array(),
				'title' => array(),
				'rel' => array()),
			'blockquote' => array('cite' => array()),
			'br' => array(),
			'p' => array(),
			'code' => array(),
			'pre' => array(),
			'em' => array(),
			'strong' => array(),
			'ul' => array(),
			'ol' => array(),
			'li' => array(),
			'h3' => array(),
			'h4' => array()
		);

		$text = balanceTags($text);
		
		$text = wp_kses( $text, $allowed );
		$text = trim($text);
		return $text;
	}

	function code_trick( $text, $markdown ) { // Don't use bbPress native function - it's incompatible with Markdown
		// If doing markdown, first take any user formatted code blocks and turn them into backticks so that
		// markdown will preserve things like underscores in code blocks
		if ( $markdown )
			$text = preg_replace_callback("!(<pre><code>|<code>)(.*?)(</code></pre>|</code>)!s", array( __CLASS__,'decodeit'), $text);

		$text = str_replace(array("\r\n", "\r"), "\n", $text);
		if ( !$markdown ) {
			// This gets the "inline" code blocks, but can't be used with Markdown.
			$text = preg_replace_callback("|(`)(.*?)`|", array( __CLASS__, 'encodeit'), $text);
			// This gets the "block level" code blocks and converts them to PRE CODE
			$text = preg_replace_callback("!(^|\n)`(.*?)`!s", array( __CLASS__, 'encodeit'), $text);
		} else {
			// Markdown can do inline code, we convert bbPress style block level code to Markdown style
			$text = preg_replace_callback("!(^|\n)([ \t]*?)`(.*?)`!s", array( __CLASS__, 'indent'), $text);
		}
		return $text;
	}

	function indent( $matches ) {
		$text = $matches[3];
		$text = preg_replace('|^|m', $matches[2] . '    ', $text);
		return $matches[1] . $text;
	}

	function encodeit( $matches ) {
		if ( function_exists('encodeit') ) // bbPress native
			return encodeit( $matches );

		$text = trim($matches[2]);
		$text = htmlspecialchars($text, ENT_QUOTES);
		$text = str_replace(array("\r\n", "\r"), "\n", $text);
		$text = preg_replace("|\n\n\n+|", "\n\n", $text);
		$text = str_replace('&amp;lt;', '&lt;', $text);
		$text = str_replace('&amp;gt;', '&gt;', $text);
		$text = "<code>$text</code>";
		if ( "`" != $matches[1] )
			$text = "<pre>$text</pre>";
		return $text;
	}

	function decodeit( $matches ) {
		if ( function_exists('decodeit') ) // bbPress native
			return decodeit( $matches );

		$text = $matches[2];
		$trans_table = array_flip(get_html_translation_table(HTML_ENTITIES));
		$text = strtr($text, $trans_table);
		$text = str_replace('<br />', '', $text);
		$text = str_replace('&#38;', '&', $text);
		$text = str_replace('&#39;', "'", $text);
		if ( '<pre><code>' == $matches[1] )
			$text = "\n$text\n";
		return "`$text`";
	}

} // end class

Class Automattic_Readme extends PucReadmeParser {}
