ajax.php

<?php

header("Access-Control-Allow-Origin: *");

function listen(){

	if(isset($_POST['write'])){

		$_POST['room'] = $_POST['write']['room'];

		if(!isset($_POST['write']['room']))

			$_POST['room'] = 'db';

		verify();

		return;

	}

	elseif(isset($_POST['load'])){

		$_POST['room'] = $_POST['load']['room'];

		if(!isset($_POST['load']['room']))

			$_POST['room'] = 'db';

		readMsg($_POST['load']["startLine"], $_POST['load']["limit"]);

	}

	elseif(isset($_POST['read'])){

		$_POST['room'] = $_POST['read']['room'];

		if(!isset($_POST['read']['room']))

			$_POST['room'] = 'db';

		readMsg($_POST["read"]["startLine"], $_POST["read"]["limit"]);

	}

	elseif(isset($_POST['lazy'])){

		$_POST['room'] = $_POST['lazy']['room'];

		if(!isset($_POST['lazy']['room']))

			$_POST['room'] = 'db';

		readMsg($_POST["lazy"]["startLine"], $_POST["lazy"]["limit"]);

	}

	elseif(isset($_POST['room'])){

		createRoomFile($_POST['room']['roomId']);

	}

}



function readMsg($start = 10, $limit = 0){

	if(!file_exists($_POST['room'].'.txt')){

		echo 'false-room';

		return;

	}

	// echo'<pre style="background:#ffffff">';

	// var_dump(file_exists($_POST['room'].'.txt'));

	// echo'</pre>';

	$f = fopen($_POST['room'].'.txt', 'r');

	$total = 0;

	while ($line = fgets($f)) {

		$total++;

	}



	$curLine = 0;

	$f = fopen($_POST['room'].'.txt', 'r');

	while ($line = fgets($f)) {

		$curLine++;

		if (($curLine >= ($total - $start))  && ($curLine <= ($total - $limit))) {

		    echo $line;

		}

	}

	fclose($f);

	return;

}



function writeMsg(){

	$date = date('Y-m-d H:i:s', strtotime("now"));

	$message = "<div class='post grid-2_3 msg-get'><b class='date'>" . $date . "</b><i class='pseudo'>" . $_POST['write']['user'] . "</i> : ";

	$message .= "<p>" . preg_replace("#<=#"," ",preg_replace("#\n#", "<br>", $_POST['write']['msg'])) . "</p>";

	$message .= "</div></br>\n";

	$f = fopen($_POST['room'].'.txt', 'a+');

	fwrite($f, $message);

	fclose($f);

	echo $message;

	return;

}



function createRoomFile($roomId){

	$f = fopen($roomId . ".txt", "x+");

	if(!$f){

		echo 'false';

		return;

	}

	echo 'true';

	return;

}



function verify(){

	if(isset($_POST['write'])){

		if(!empty($_POST['write']['user']) && strlen($_POST['write']['user']) > 2

			&& !empty($_POST['write']['msg']) && strlen($_POST['write']['msg']) > 1){

			// prevent html code

			$_POST['write']['msg'] = trim(strip_tags($_POST['write']['msg']));

			if(empty($_POST['write']['msg'])){

				echo 'false';

				return;

			}

			writeMsg();

		}

		else{

			echo 'false';

			return;

		}



	}

}



listen();