<?php
register_module([
	"name" => "Parsedown",
	"version" => "0.3.1",
	"author" => "Emanuil Rusev & Starbeamrainbowlabs",
	"description" => "An upgraded (now default!) parser based on Emanuil Rusev's Parsedown Extra PHP library (https://github.com/erusev/parsedown-extra), which is licensed MIT. Please be careful, as this module adds a some weight to your installation, and also *requires* write access to the disk on first load.",
	"id" => "parser-parsedown",
	"code" => function() {
		global $settings;
		
		$parser = new PeppermintParsedown();
		$parser->setInternalLinkBase("?page=%s");
		add_parser("parsedown", function($source) use ($parser) {
			$result = $parser->text($source);
			
			return $result;
		});
		
		add_help_section("20-parser-default", "Editor Syntax",
		"<p>$settings->sitename's editor uses an extended version of <a href='http://parsedown.org/'>Parsedown</a> to render pages, which is a fantastic open source Github flavoured markdown parser. You can find a quick reference guide on Github flavoured markdown <a href='https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet'>here</a> by <a href='https://github.com/adam-p/'>adam-p</a>, or if you prefer a book <a href='https://www.gitbook.com/book/roachhd/master-markdown/details'>Mastering Markdown</a> by KB is a good read, and free too!</p>
		<h3>Extra Syntax</h3>
		<p>$settings->sitename's editor also supports some extra custom syntax, some of which is inspired by <a href='https://mediawiki.org/'>Mediawiki</a>.
		<table>
			<tr><th style='width: 40%'>Type this</th><th style='width: 20%'>To get this</th><th>Comments</th></th>
			<tr><td><code>[[Internal link]]</code></td><td><a href='?page=Internal%20link'>Internal Link</a></td><td>An internal link.</td></tr>
			<tr><td><code>[[Display Text|Internal link]]</code></td><td><a href='?page=Internal%20link'>Display Text</a></td><td>An internal link with some display text.</td></tr>
			<tr><td><code>![Alt text](http://example.com/path/to/image.png | 256x256 | right)</code></td><td><img src='http://example.com/path/to/image.png' alt='Alt text' style='float: right; max-width: 256px; max-height: 256px;' /></td><td>An image floating to the right of the page that fits inside a 256px x 256px box, preserving aspect ratio.</td></tr>
		</table>
		<h4>Templating</h4>
		<p>$settings->sitename also supports including one page in another page as a <em>template</em>. The syntax is very similar to that of Mediawiki. For example, <code>{{Announcement banner}}</code> will include the contents of the \"Announcement banner\" page, assuming it exists.</p>
		<p>You can also use variables. Again, the syntax here is very similar to that of Mediawiki - they can be referenced in the included page by surrrounding the variable name in triple curly braces (e.g. <code>{{{Announcement text}}}</code>), and set when including a page with the bar syntax (e.g. <code>{{Announcement banner | importance = high | text = Maintenance has been planned for tonight.}}</code>). Currently the only restriction in templates and variables is that you may not include a closing curly brace (<code>}</code>) in the page name, variable name, or value.</p>");
	}
]);

/*** Parsedown versions ***
 * Parsedown Core: 1.6.0  *
 * Parsedown Extra: 0.7.0 *
 **************************/
$env->parsedown_paths = new stdClass();
$env->parsedown_paths->parsedown = "https://cdn.rawgit.com/erusev/parsedown/3ebbd730b5c2cf5ce78bc1bf64071407fc6674b7/Parsedown.php";
$env->parsedown_paths->parsedown_extra = "https://cdn.rawgit.com/erusev/parsedown-extra/11a44e076d02ffcc4021713398a60cd73f78b6f5/ParsedownExtra.php";

// Download parsedown and parsedown extra if they don't already exist
if(!file_exists("./Parsedown.php") || filesize("./Parsedown.php") === 0)
	file_put_contents("./Parsedown.php", fopen($env->parsedown_paths->parsedown, "r"));
if(!file_exists("./ParsedownExtra.php") || filesize("./ParsedownExtra.php") === 0)
	file_put_contents("./ParsedownExtra.php", fopen($env->parsedown_paths->parsedown_extra, "r"));

require_once("./Parsedown.php");
require_once("./ParsedownExtra.php");

/*
 * ██████   █████  ██████  ███████ ███████ ██████   ██████  ██     ██ ███    ██
 * ██   ██ ██   ██ ██   ██ ██      ██      ██   ██ ██    ██ ██     ██ ████   ██
 * ██████  ███████ ██████  ███████ █████   ██   ██ ██    ██ ██  █  ██ ██ ██  ██
 * ██      ██   ██ ██   ██      ██ ██      ██   ██ ██    ██ ██ ███ ██ ██  ██ ██
 * ██      ██   ██ ██   ██ ███████ ███████ ██████   ██████   ███ ███  ██   ████
 * 
 * ███████ ██   ██ ████████ ███████ ███    ██ ███████ ██  ██████  ███    ██ ███████
 * ██       ██ ██     ██    ██      ████   ██ ██      ██ ██    ██ ████   ██ ██
 * █████     ███      ██    █████   ██ ██  ██ ███████ ██ ██    ██ ██ ██  ██ ███████
 * ██       ██ ██     ██    ██      ██  ██ ██      ██ ██ ██    ██ ██  ██ ██      ██
 * ███████ ██   ██    ██    ███████ ██   ████ ███████ ██  ██████  ██   ████ ███████
*/
class PeppermintParsedown extends ParsedownExtra
{
	private $internalLinkBase = "./%s";
	
	protected $maxParamDepth = 0;
	protected $paramStack = [];
	
	function __construct()
	{
		// Prioritise our internal link parsing over the regular link parsing
		array_unshift($this->InlineTypes["["], "InternalLink");
		// Prioritise our image parser over the regular image parser
		array_unshift($this->InlineTypes["!"], "ExtendedImage");
		
		$this->inlineMarkerList .= "{";
		if(!is_array($this->InlineTypes["{"]))
			$this->InlineTypes["{"] = [];
		$this->InlineTypes["{"][] = "Template";
	}
	
	protected function inlineTemplate($fragment)
	{
		global $env;
		
		// Variable parsing
		if(preg_match("/\{\{\{([^}]+)\}\}\}/", $fragment["text"], $matches))
		{
			$stackEntry = array_slice($this->paramStack, -1)[0];
			$params = !empty($stackEntry) ? $stackEntry["params"] : false;
			
			$variableKey = trim($matches[1]);
			
			$variableValue = false;
			switch ($variableKey)
			{
				case "@":
					if(!empty($params))
					{
						$variableValue = "<table>
	<tr><th>Key</th><th>Value</th></tr>\n";
						foreach($params as $key => $value)
						{
							$variableValue .= "\t<tr><td>" . $this->escapeText($key) . "</td><td>" . $this->escapeText($value) . "</td></tr>\n";
						}
						$variableValue .= "</table>";
					}
					break;
				case "#":
					$variableValue = "<ol start=\"0\">\n";
					$variableValue .= "\t<li>$env->page</li>\n";
					foreach($this->paramStack as $curStackEntry)
					{
						$variableValue .= "\t<li>" . $curStackEntry["pagename"] . "</li>\n";
					}
					$variableValue .= "</ol>\n";
			}
			if(isset($params[$variableKey]))
			{
				$variableValue = $params[$variableKey];
				$variableValue = $this->escapeText($variableValue);
			}
			
			if($variableValue)
			{
				return [
					"extent" => strlen($matches[0]),
					"markup" => $variableValue
				];
			}
		}
		else if(preg_match("/\{\{([^}]+)\}\}/", $fragment["text"], $matches))
		{
			$templateElement = $this->templateHandler($matches[1]);
			
			if(!empty($templateElement))
			{
				return [
					"extent" => strlen($matches[0]),
					"element" => $templateElement
				];
			}
		}
	}
	
	protected function templateHandler($source)
	{
		global $pageindex, $paths;
		
		
		$parts = explode("|", trim($source, "{}"));
		$parts = array_map(trim, $parts);
		
		// Extract the name of the temaplate page
		$templatePagename = array_shift($parts);
		// If the page that we are supposed to use as the tempalte doesn't
		// exist, then there's no point in continuing.
		if(empty($pageindex->$templatePagename))
			return false;
		
		// Parse the parameters
		$this->maxParamDepth++;
		$params = [];
		$i = 0;
		foreach($parts as $part)
		{
			if(strpos($part, "=") !== false)
			{
				// This param contains an equals sign, so it's a named parameter
				$keyValuePair = explode("=", $part, 2);
				$keyValuePair = array_map(trim, $keyValuePair);
				$params[$keyValuePair[0]] = $keyValuePair[1];
			}
			else
			{
				// This isn't a named parameter
				$params["$i"] = trim($part);
				
				$i++;
			}
		}
		// Add the parsed parameters to the parameter stack
		$this->paramStack[] = [
			"pagename" => $templatePagename,
			"params" => $params
		];
		
		$templateFilePath = $paths->storage_prefix . $pageindex->$templatePagename->filename;
		
		$parsedTemplateSource = $this->text(file_get_contents($templateFilePath));
		
		// Remove the parsed parameters from the stack
		array_pop($this->paramStack);
		
		return [
			"name" => "div",
			"text" => $parsedTemplateSource,
			"attributes" => [
				"class" => "template"
			]
		];
	}
	
	protected function inlineInternalLink($fragment)
	{
		if(preg_match('/^\[\[(.*)\]\]/', $fragment["text"], $matches))
		{
			$display = $linkPage = $matches[1];
			if(strpos($matches[1], "|"))
			{
				// We have a bar character
				$parts = explode("|", $matches[1], 2);
				$linkPage = $parts[0];
				$display = $parts[1];
			}
			
			// Construct the full url
			$linkUrl = str_replace(
				"%s", rawurlencode($linkPage),
				$this->internalLinkBase
			);
			
			return [
				"extent" => strlen($matches[0]),
				"element" => [
					"name" => "a",
					"text" => $display,
					"attributes" => [
						"href" => $linkUrl
					]
				]
			];
		}
		return;
	}
	
	protected function inlineExtendedImage($fragment)
	{
		if(preg_match('/^!\[(.*)\]\(([^ |)]+)\s*\|([^|)]*)(?:\|([^)]*))?\)/', $fragment["text"], $matches))
		{
			/*
			 * 0 - Everything
			 * 1 - Alt text
			 * 2 - Url
			 * 3 - First param
			 * 4 - Second Param (optional)
			 */
			
			var_dump($matches);
			
			$altText = $matches[1];
			$imageUrl = $matches[2];
			$param1 = strtolower(trim($matches[3]));
			$param2 = empty($matches[4]) ? false : strtolower(trim($matches[4]));
			$floatDirection = false;
			$imageSize = false;
			
			if($this->isFloatValue($param1))
			{
				$floatDirection = $param1;
				$imageSize = $this->parseSizeSpec($param2);
			}
			else if($this->isFloatValue($param2))
			{
				$floatDirection = $param2;
				$imageSize = $this->parseSizeSpec($param1);
			}
			else
			{
				$imageSize = $this->parseSizeSpec($param1);
			}
			
			// If they are both invalid then something very strange is going on
			// Let the built in parsedown image handler deal with it
			if($imageSize === false && $floatDirection === false)
				return;
			
			$style = "";
			if($imageSize !== false)
				$style .= " max-width: " . $imageSize["x"] . "px; max-height: " . $imageSize["y"] . "px;";
			if($floatDirection)
				$style .= " float: $floatDirection;";
			
			return [
				"extent" => strlen($matches[0]),
				"element" => [
					"name" => "img",
					"attributes" => [
						"src" => $imageUrl,
						"alt" => $altText,
						"style" => trim($style)
					]
				]
			];
		}
	}
	
	# ~
	# Utility Methods
	# ~
	
	private function isFloatValue($value)
	{
		return in_array(strtolower($value), [ "left", "right" ]);
	}
	
	private function parseSizeSpec($text)
	{
		if(strpos($text, "x") === false)
			return false;
		$parts = explode("x", $text, 2);
		
		if(count($parts) != 2)
			return false;
		
		array_map("trim", $parts);
		array_map("intval", $parts);
		
		if(in_array(0, $parts))
			return false;
		
		return [
			"x" => $parts[0],
			"y" => $parts[1]
		];
	}
	
	protected function escapeText($text)
	{
		return htmlentities($text, ENT_COMPAT | ENT_HTML5);
	}
	
	/**
	 * Sets the base url to be used for internal links. '%s' will be replaced
	 * with a URL encoded version of the page name.
	 * @param string $url The url to use when parsing internal links.
	 */
	public function setInternalLinkBase($url)
	{
		$this->internalLinkBase = $url;
	}
}

?>
Type this	To get this	Comments
`[[Internal link]]`	Internal Link	An internal link.
`[[Display Text\|Internal link]]`	Display Text	An internal link with some display text.
`![Alt text](http://example.com/path/to/image.png \| 256x256 \| right)`		An image floating to the right of the page that fits inside a 256px x 256px box, preserving aspect ratio.