qa-chat.php

<?php
/*
	Question2Answer Chat Room plugin
	License: http://www.gnu.org/licenses/gpl.html
*/

require_once QA_INCLUDE_DIR.'app/users.php';

class qa_chat
{
	private $directory;
	private $urltoroot;
	private $user;
	private $dates;

	private $optactive = 'chat_active';
	private $optkick = 'chat_kick_level';
	private $optcss = 'chat_hide_css';

	// TODO: get the proper language text, this is all a quick fix at the moment
	private $userlevels = [
		'editor' => QA_USER_LEVEL_EDITOR,
		'mod'    => QA_USER_LEVEL_MODERATOR,
		'admin'  => QA_USER_LEVEL_ADMIN,
	];

	private $userlevels_text = [
		'editor' => 'Editor',
		'mod'    => 'Moderator',
		'admin'  => 'Administrator',
	];

	public function load_module($directory, $urltoroot)
	{
		$this->directory = $directory;
		$this->urltoroot = $urltoroot;
	}

	public function option_default($option)
	{
		switch ($option) {
			case $this->optactive:
				return 0;
			case $this->optkick:
				return QA_USER_LEVEL_ADMIN;
			case $this->optcss:
				return 0;
			default:
				break;
		}
	}

	// set admin options
	function admin_form(&$qa_content)
	{
		$saved_msg = null;

		if (qa_clicked('chat_save')) {
			// kick level option
			$kicklevel = qa_post_text('ch_kicklevel');
			if (!in_array($kicklevel, array_keys($this->userlevels))) {
				$kicklevel = 'admin';
			}
			qa_opt($this->optkick, $this->userlevels[$kicklevel]);

			// css option
			$hidecss = qa_post_text('ch_hidecss') ? '1' : '0';
			qa_opt($this->optcss, $hidecss);

			$saved_msg = 'Options saved.';
		}

		$kl_id = qa_opt($this->optkick);
		$kl_alias = array_search($kl_id, $this->userlevels);
		$kl_value = $this->userlevels_text[$kl_alias];

		return [
			'ok' => $saved_msg,
			'style' => 'wide',
			'note' => array_search(qa_opt($this->optkick), $this->userlevels),

			'fields' => [
				'kicklevel' => [
					'type' => 'select',
					'label' => 'Kick level',
					'tags' => 'NAME="ch_kicklevel"',
					'options' => $this->userlevels_text,
					'value' => $kl_value,
					'note' => 'Which user level is able to kick other users.',
				],
				'css' => [
					'type' => 'checkbox',
					'label' => 'Don\'t add CSS inline',
					'tags' => 'NAME="ch_hidecss"',
					'value' => qa_opt($this->optcss) === '1',
					'note' => 'Tick if you added the CSS to your own stylesheet (more efficient).',
				],
			],

			'buttons' => [
				'save' => [
					'tags' => 'NAME="chat_save"',
					'label' => 'Save options',
					'value' => '1',
				],
			],
		];
	}

	public function suggest_requests() // for display in admin interface
	{
		return [
			[
				'title' => 'Chat Room',
				'request' => 'chat',
				'nav' => 'M', // 'M'=main, 'F'=footer, 'B'=before main, 'O'=opposite main, null=none
			],
		];
	}

	public function match_request($request)
	{
		return $request == 'chat';
	}

	function init_queries($tableslc)
	{
		$tbl1 = qa_db_add_table_prefix('chat_posts');
		$tbl2 = qa_db_add_table_prefix('chat_users');

		if (in_array($tbl1, $tableslc) && in_array($tbl2, $tableslc)) {
			qa_opt($this->optactive, '1');
			return null;
		}

		return [
			'CREATE TABLE IF NOT EXISTS ^chat_posts (
			  `postid` int(10) unsigned NOT NULL AUTO_INCREMENT,
			  `userid` int(10) unsigned NOT NULL,
			  `posted` datetime NOT NULL,
			  `message` varchar(800) NOT NULL,
			  PRIMARY KEY (`postid`),
			  KEY `posted` (`posted`)
			) ENGINE=InnoDB  DEFAULT CHARSET=utf8',

			'CREATE TABLE IF NOT EXISTS ^chat_users (
			  `userid` int(10) unsigned NOT NULL,
			  `lastposted` datetime NOT NULL,
			  `lastpolled` datetime NOT NULL,
			  `kickeduntil` datetime NOT NULL DEFAULT "2012-01-01 00:00:00",
			  PRIMARY KEY (`userid`),
			  KEY `active` (`lastpolled`)
			) ENGINE=InnoDB DEFAULT CHARSET=utf8',

			'CREATE TABLE IF NOT EXISTS ^chat_kicks (
			  `userid` int(10) unsigned NOT NULL,
			  `kickedby` int(10) unsigned NOT NULL,
			  `whenkicked` datetime NOT NULL,
			  PRIMARY KEY (`userid`,`kickedby`)
			) ENGINE=InnoDB DEFAULT CHARSET=utf8',
		];
	}

	/*
		MAIN function: display the chat room, or run an AJAX request
	*/
	public function process_request($request)
	{
		// set up user
		$this->user = [
			'id' => qa_get_logged_in_userid(),
			'handle' => qa_get_logged_in_handle(),
			'flags' => qa_get_logged_in_flags(),
			'level' => qa_get_logged_in_level(),
		];

		// check if user is banned (kicked)
		$sql = 'SELECT kickeduntil, (kickeduntil-NOW() > 0) AS iskicked FROM ^chat_users WHERE userid=#';
		$result = qa_db_query_sub($sql, $this->user['id']);
		$row = qa_db_read_one_assoc($result, true);
		$this->user['iskicked'] = @$row['iskicked'];
		$this->user['kickeduntil'] = @$row['kickeduntil'];

		// create dates for database
		$now = time();
		$this->dates = [
			'posted' => gmdate('Y-m-d H:i:s', $now),
			'posted_utc' => gmdate('Y-m-d\TH:i:s\Z', $now),
		];

		$opt_kicklevel = qa_opt($this->optkick);

		// AJAX: someone posted a message
		$message = qa_post_text('ajax_add_message');
		if ($message !== null) {
			if (!$this->user_perms_post()) {
				echo "QA_AJAX_RESPONSE\n0\nYou are not allowed to post currently, sorry.";
				return;
			}

			// prevent just spaces
			$message = trim($message);
			if (strlen($message) == 0) {
				echo "QA_AJAX_RESPONSE\n0\nThe message you post must actually be something.";
				return;
			}

			$data = [
				'userid' => $this->user['id'],
				'username' => $this->user['handle'],
				'posted' => $this->dates['posted'],
				'posted_utc' => $this->dates['posted_utc'],
				'message' => $message,
			];

			// save to database
			$data['postid'] = $this->post_message($data);
			$this->update_activity(true);

			$data['username'] = qa_html($data['username']);
			$data['message'] = $this->format_message($data['message']);

			header('Content-Type: text/plain; charset=utf-8');
			echo "QA_AJAX_RESPONSE\n" . $this->user['id'] . "\n" . json_encode($data);
			return;
		}

		// AJAX: polling check; $lastid=0 on initial page load
		$lastid = qa_post_text('ajax_get_messages');
		if ($lastid !== null) {
			if (!$this->user_perms_view()) {
				echo "QA_AJAX_RESPONSE\n0\nYou don't appear to be logged in. Please reload the page.";
				return;
			}
			if ($this->user_perms_kicked()) {
				echo "QA_AJAX_RESPONSE\n0\nYou have been kicked. Please reload the page.";
				return;
			}

			$this->update_activity($lastid == 0);
			$messages = $this->get_messages($lastid);
			$users = $this->users_online();

			header('Content-Type: text/plain; charset=utf-8');
			echo "QA_AJAX_RESPONSE\n" . $this->user['id'] . "\n" . json_encode($messages) . "\n" . json_encode($users);
			return;
		}

		// AJAX: request to kick user
		$kickuserid = qa_post_text('ajax_kick_userid');
		$kickhandle = qa_post_text('ajax_kick_username');
		if ($kickuserid !== null) {
			// make sure user is correct level as set in options
			if ($this->user['level'] < $opt_kicklevel) {
				echo "QA_AJAX_RESPONSE\n0\nYou are not allowed to do that currently, sorry.";
				return;
			}

			$this->kick_user($kickuserid, $kickhandle);

			header('Content-Type: text/plain; charset=utf-8');
			echo "QA_AJAX_RESPONSE\n" . $this->user['id'] . "\nGave 'em a right kickin'!";
			return;
		}


		// regular page request
		$qa_content = qa_content_prepare();
		$qa_content['title'] = 'Chat Room';
		$qa_content['script_rel'][] = $this->urltoroot.'qa-chat.js?v=1.7';

		if ($this->user_perms_post()) {
			$qa_content['custom_form'] =
				'<form method="post" id="qa-chat-form">' .
				'	<input id="message" class="qa-chat-post" type="text" name="ajax_add_message" autocomplete="off" maxlength="800">' .
				'	<input type="submit" class="qa-chat-post-btn" value="Post">' .
				'</form>' .
				'<ul id="qa-chat-list"></ul>';

		} else if ($this->user_perms_kicked()) {
			$ktil_utc = gmdate('Y-m-d\TH:i:s\Z', strtotime($this->user['kickeduntil']));
			$qa_content['error'] =
				'Sorry, you have been kicked from chat temporarily. Take a few moments to chill.<br>' .
				'The ban expires <span id="qa_chat_kickeduntil" data-utc="' . $ktil_utc . '" title="' . $ktil_utc . '">soon</span>' .
				'<script>$("#qa_chat_kickeduntil").timeago();</script>';

		} else if ($this->user_perms_view()) {
			$qa_content['error'] = 'Sorry, you are currently unable to post in chat. If you are new, you must confirm your email address.';

		} else {
			$qa_content['error'] = qa_insert_login_links('Please ^1log in^2 or ^3register^4 to use the chat room.', $request);
		}

		return $qa_content;
	}



	// fetch all messages after given id
	private function get_messages($lastid)
	{
		$sql =
			'SELECT p.postid, p.userid, u.handle AS username, p.message AS message,
			   p.posted, DATE_FORMAT(p.posted, "%Y-%m-%dT%H:%i:%sZ") AS posted_utc
			 FROM ^chat_posts p LEFT JOIN ^users u ON u.userid=p.userid
			 WHERE p.postid > #
			 ORDER BY p.posted DESC LIMIT 80';
		$result = qa_db_query_sub($sql, $lastid);

		$messages = qa_db_read_all_assoc($result);

		foreach ($messages as &$m) {
			$m['message'] = $this->format_message($m['message']);
			$m['username'] = qa_html($m['username']);
		}

		return $messages;
	}

	// save message to database
	private function post_message($data)
	{
		$sql = 'INSERT INTO ^chat_posts (postid, userid, posted, message) VALUES (0, #, $, $)';
		qa_db_query_sub($sql, $data['userid'], $data['posted'], $data['message']);

		return qa_db_last_insert_id();
	}

	// update user activity
	private function update_activity($posted = false)
	{
		if ($posted) {
			$sql = 'INSERT INTO ^chat_users (userid, lastposted, lastpolled) VALUES (#, NOW(), NOW()) ON DUPLICATE KEY UPDATE lastposted=NOW(), lastpolled=NOW()';
		} else {
			$sql = 'INSERT INTO ^chat_users (userid, lastpolled) VALUES (#, NOW()) ON DUPLICATE KEY UPDATE lastpolled=NOW()';
		}

		qa_db_query_sub($sql, $this->user['id']);
	}

	// get recently active users
	private function users_online()
	{
		$sql =
			'SELECT u.userid, u.handle AS username, u.level, (c.lastposted < DATE_SUB(NOW(), INTERVAL 8 MINUTE)) AS idle, (c.kickeduntil > NOW()) AS kicked
			 FROM ^users u, ^chat_users c
			 WHERE u.userid=c.userid AND c.lastpolled > DATE_SUB(NOW(), INTERVAL 1 MINUTE)
			 ORDER BY u.handle';
		$result = qa_db_query_sub($sql);

		$users = qa_db_read_all_assoc($result);
		$opt_kicklevel = qa_opt($this->optkick);

		foreach ($users as &$u) {
			$u['username'] = qa_html($u['username']);
			$kickable = $u['level'] < $opt_kicklevel && $this->user['level'] >= $opt_kicklevel;
			$u['kickable'] = $kickable ? '1' : '0';
		}

		return $users;
	}

	// votes to kick a user; mods/admins can kick users straight away
	private function kick_user($kickuserid, $kickhandle)
	{
		$sql = 'INSERT INTO ^chat_kicks (userid, kickedby, whenkicked) VALUES (#, #, NOW()) ON DUPLICATE KEY UPDATE whenkicked=NOW()';
		qa_db_query_sub($sql, $kickuserid, $this->user['id']);

		$sql = 'UPDATE ^chat_users SET kickeduntil = DATE_ADD(NOW(), INTERVAL 10 MINUTE) WHERE userid=#';
		$result = qa_db_query_sub($sql, $kickuserid);

		if ($result) {
			$message = [
				'userid' => '0',
				'posted' => $this->dates['posted'],
				'message' => qa_html($kickhandle) . ' has been kicked off chat for 10 minutes.',
			];
			$this->post_message($message);
		}
	}

	// check user permissions for viewing page
	private function user_perms_view()
	{
		return $this->user['id'] > 0;
	}

	// check if user was kicked
	private function user_perms_kicked()
	{
		return $this->user['iskicked'] > 0;
	}

	// check user permissions for posting messages
	private function user_perms_post()
	{
		return qa_user_permit_error() === false && !$this->user['iskicked'] && (
			($this->user['level'] >= QA_USER_LEVEL_EXPERT) ||
			($this->user['flags'] & QA_USER_FLAGS_EMAIL_CONFIRMED)
		);
	}

	// format message
	private function format_message($msg)
	{
		// censor bad words
		require_once QA_INCLUDE_DIR.'util/string.php';
		$blockwordspreg = qa_get_block_words_preg();

		$msg = qa_block_words_replace($msg, $blockwordspreg);
		$msg = qa_html($msg);

		return qa_html_convert_urls($msg);
	}
}