<?php
# Solution to CSE 154 Flashcard lab.
# generates a JSON list of categories if passed a parameter mode
# with the value of categories. Otherwise outputs a random question
# from the passed in category in XML.

$mode = $_GET["mode"];
$category = $_GET["category"];

#clarification: there are permissions problems with accessing the absolute URL
#so we have to use a relative URL. each time we use "../" we go backwards one directory
#depending on your file structure on webster you may need more  "../"
$url = "../../cse154/services/flashcards/";

if($mode == "categories") {
	outputJson($url);
} else {
	outputXml($url, $category);
}

# outputs the list of available categories in JSON
function outputJson($url) {

	$files = glob($url . "*");
	$json = array("categories" => array());

	foreach($files as $file) {
		$count = count(glob($file."/*"));
		#add name value pairs to array one at a time in the form "pokemon => 3"
		$json["categories"][basename($file)] = $count;
	}
	
	header("Content-type: application/json");
	print(json_encode($json));
}

# outputs a random question about the provided category in XML
function outputXml($url, $category) {
	$files = glob($url . "$category/*");
	$index = array_rand($files);
	// this is a great place to use list!!
	list($ques, $ans) = file($files[$index]);

	$dom = new DOMDocument();
	$card = $dom->createElement("card");
	$dom->appendChild($card);
	$question = $dom->createElement("question");
	$question->appendChild($dom->createTextNode($ques));
	$card->appendChild($question);
	$answer = $dom->createElement("answer");
	$answer->appendChild($dom->createTextNode($ans));
	$card->appendChild($answer);

	header("Content-type: text/xml");
	print($dom->saveXML());
}

?>