<?php
/**
 * Name: Extension Manager
 * Author: Shish <webmaster@shishnet.org>
 * Link: http://code.shishnet.org/shimmie2/
 * License: GPLv2
 * Visibility: admin
 * Description: A thing for point & click extension management
 * Documentation:
 *   Allows the admin to view a list of all extensions and enable or
 *   disable them; also allows users to view the list of activated
 *   extensions and read their documentation
 */

/** @private */
function __extman_extcmp(ExtensionInfo $a, ExtensionInfo $b) {
	return strcmp($a->name, $b->name);
}

/** @private */
class ExtensionInfo {
	var $ext_name, $name, $link, $author, $email;
	var $description, $documentation, $version, $visibility;
	var $enabled;

	public function __construct($main) {
		$matches = array();
		$lines = file($main);
		$number_of_lines = count($lines);
		preg_match("#ext/(.*)/main.php#", $main, $matches);
		$this->ext_name = $matches[1];
		$this->name = $this->ext_name;
		$this->enabled = $this->is_enabled($this->ext_name);

		for($i=0; $i<$number_of_lines; $i++) {
			$line = $lines[$i];
			if(preg_match("/Name: (.*)/", $line, $matches)) {
				$this->name = $matches[1];
			}
			else if(preg_match("/Visibility: (.*)/", $line, $matches)) {
				$this->visibility = $matches[1];
			}
			else if(preg_match("/Link: (.*)/", $line, $matches)) {
				$this->link = $matches[1];
				if($this->link[0] == "/") {
					$this->link = make_link(substr($this->link, 1));
				}
			}
			else if(preg_match("/Version: (.*)/", $line, $matches)) {
				$this->version = $matches[1];
			}
			else if(preg_match("/Author: (.*) [<\(](.*@.*)[>\)]/", $line, $matches)) {
				$this->author = $matches[1];
				$this->email = $matches[2];
			}
			else if(preg_match("/Author: (.*)/", $line, $matches)) {
				$this->author = $matches[1];
			}
			else if(preg_match("/(.*)Description: ?(.*)/", $line, $matches)) {
				$this->description = $matches[2];
				$start = $matches[1]." ";
				$start_len = strlen($start);
				while(substr($lines[$i+1], 0, $start_len) == $start) {
					$this->description .= " ".substr($lines[$i+1], $start_len);
					$i++;
				}
			}
			else if(preg_match("/(.*)Documentation: ?(.*)/", $line, $matches)) {
				$this->documentation = $matches[2];
				$start = $matches[1]." ";
				$start_len = strlen($start);
				while(substr($lines[$i+1], 0, $start_len) == $start) {
					$this->documentation .= " ".substr($lines[$i+1], $start_len);
					$i++;
				}
				$this->documentation = str_replace('$site', make_http(get_base_href()), $this->documentation);
			}
			else if(preg_match("/\*\//", $line, $matches)) {
				break;
			}
		}
	}

	/**
	 * @param string $fname
	 * @return bool|null
	 */
	private function is_enabled(/*string*/ $fname) {
		$core = explode(",", CORE_EXTS);
		$extra = explode(",", EXTRA_EXTS);

		if(in_array($fname, $extra)) return true; // enabled
		if(in_array($fname, $core)) return null; // core
		return false; // not enabled
	}
}

class ExtManager extends Extension {
	public function onPageRequest(PageRequestEvent $event) {
		global $page, $user;
		if($event->page_matches("ext_manager")) {
			if($user->can("manage_extension_list")) {
				if($event->get_arg(0) == "set" && $user->check_auth_token()) {
					if(is_writable("data/config")) {
						$this->set_things($_POST);
						log_warning("ext_manager", "Active extensions changed", true);
						$page->set_mode("redirect");
						$page->set_redirect(make_link("ext_manager"));
					}
					else {
						$this->theme->display_error(500, "File Operation Failed",
							"The config file (data/config/extensions.conf.php) isn't writable by the web server :(");
					}
				}
				else {
					$this->theme->display_table($page, $this->get_extensions(true), true);
				}
			}
			else {
				$this->theme->display_table($page, $this->get_extensions(false), false);
			}
		}

		if($event->page_matches("ext_doc")) {
			$ext = $event->get_arg(0);
			if(file_exists("ext/$ext/main.php")) {
				$info = new ExtensionInfo("ext/$ext/main.php");
				$this->theme->display_doc($page, $info);
			}
			else {
				$this->theme->display_table($page, $this->get_extensions(false), false);
			}
		}
	}

	public function onCommand(CommandEvent $event) {
		if($event->cmd == "help") {
			print "\tdisable-all-ext\n";
			print "\t\tdisable all extensions\n\n";
		}
		if($event->cmd == "disable-all-ext") {
			$this->write_config(array());
		}
	}


	public function onUserBlockBuilding(UserBlockBuildingEvent $event) {
		global $user;
		if($user->can("manage_extension_list")) {
			$event->add_link("Extension Manager", make_link("ext_manager"));
		}
		else {
			$event->add_link("Help", make_link("ext_doc"));
		}
	}

	/**
	 * @param bool $all
	 * @return ExtensionInfo[]
	 */
	private function get_extensions(/*bool*/ $all) {
		$extensions = array();
		if($all) {
			$exts = zglob("ext/*/main.php");
		}
		else {
			$exts = zglob("ext/{".ENABLED_EXTS."}/main.php");
		}
		foreach($exts as $main) {
			$extensions[] = new ExtensionInfo($main);
		}
		usort($extensions, "__extman_extcmp");
		return $extensions;
	}

	private function set_things($settings) {
		$core = explode(",", CORE_EXTS);
		$extras = array();

		foreach(glob("ext/*/main.php") as $main) {
			$matches = array();
			preg_match("#ext/(.*)/main.php#", $main, $matches);
			$fname = $matches[1];

			if(!in_array($fname, $core) && isset($settings["ext_$fname"])) {
				$extras[] = $fname;
			}
		}

		$this->write_config($extras);
	}

	private function write_config($extras) {
		file_put_contents(
			"data/config/extensions.conf.php",
			'<'.'?php'."\n".
			'define("EXTRA_EXTS", "'.implode(",", $extras).'");'."\n".
			'?'.">"
		);

		// when the list of active extensions changes, we can be
		// pretty sure that the list of who reacts to what will
		// change too
		if(file_exists("data/cache/event_listeners.php")) {
			unlink("data/cache/event_listeners.php");
		}
	}
}