renderTable();

var timeblocks;
var courselist_arr;

function renderTable()
{
	timeblocks = [];
	var scheduleTable = document.getElementById("scheduleTable");
	
	scheduleTable.className = "schedule";
//	scheduleTable.innerHTML = '';
	
	// 8:00 through 21:00 is all we care about since no classes run earlier/later
	for(var i = 8; i < 21; i++)
	{
		var timeblock = document.createElement("tbody");
		timeblock.className = "timeblock-no";
		
		var hour = i % 12;
		hour = hour ? hour : 12;
		
		timeblocks[i] = timeblock;
		
		for(var mins = 0; mins < 60; mins += 15)
		{
			var timeblock_row = document.createElement("tr");
		
			if(mins == 0) // since the header rowspans by 4, you only need one of these to cover all four slots
			{
				var timeblock_row_header = document.createElement("td");
				timeblock_row_header.className = "time";
				timeblock_row_header.rowSpan = 4;
				timeblock_row_header.innerHTML = hour + ":00";
				
				timeblock_row.appendChild(timeblock_row_header);
				
				timeblock_row.className = "first-child";
			}
			
			for(var day = 0; day < 7; day++)
			{
				var timeblock_row_day = document.createElement("td");
				timeblock_row_day.className = "Day" + day;
				timeblock_row.appendChild(timeblock_row_day);
			}
			
			timeblock.appendChild(timeblock_row);
		}
	
		scheduleTable.appendChild(timeblock);
	}
}

var req;
// set up the AJAX object
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest) {
    req = new XMLHttpRequest();
// branch for IE/Windows ActiveX version
} else if (window.ActiveXObject) {
    req = new ActiveXObject("Microsoft.XMLHTTP");
}

document.getElementById("termlist").onchange = termChange;
document.getElementById("courselist").onchange = courseChange;

function courseChange()
{
	var courseselect = document.getElementById('courselist');
	
	// destroy all unsaved classes
	DestroyUnsaved();
	
	var courseinfo = courseselect.options[courseselect.selectedIndex]['courseinfo'];
	var new_course = new Course(courseinfo);
	new_course.Render();
}

function processCourseReqChange()
{
	var courseselect = document.getElementById('courselist');
	var loadingbox = document.getElementById('loadingbox');
	
	if(req.readyState == 4)
	{
		if(req.status == 200)
		{
			var response = req.responseXML.documentElement;
			var courses = response.getElementsByTagName('Course');

			for(var course = 0; course < courses.length; ++course)
			{
				var newcourse = document.createElement('option');
				newcourse.text = courses[course].getAttribute("Section") + ": " + courses[course].getAttribute("Title");
				newcourse.value = courses[course].getAttribute("CallNumber");
				newcourse['courseinfo'] = courses[course];
				
				courselist_arr.push(newcourse);
				
				try {
					courseselect.add(newcourse, null);
				} catch(ex) {
					courseselect.add(newcourse);
				}
			}
		}
		else
		{
			alert("There was a problem retrieving the XML data:\n" + req.statusText);
		}
		courseselect.className = "";
	
		if(loadingbox !== null)
			loadingbox.className = "";
			
		do_filtering();
	}
	else
	{
		courseselect.className = "loading";
		if(loadingbox !== null)
			loadingbox.className = "loading";
	}
}

function courseClear()
{
	var courseselect = document.getElementById('courselist');
		
	// clear out the courses
	for(var courseopt = 0; courseopt < courseselect.options.length; )
	{
		if(courseopt == 'length')
			break;
			
		courseselect.remove(courseopt);
	}
}

function termChange()
{
	var termselect = document.getElementById("termlist");
	var termcode = termselect.options[termselect.selectedIndex].value;
	
	var courseselect = document.getElementById('courselist');
	
	// destroy all unsaved classes
	DestroyUnsaved();
	
	// clear out the course list
	courseClear(); // clear the box
	courselist_arr = []; // clear the array
	
	document.getElementById("course-search").value = "Search...";
	document.getElementById("course-search").className = "default";
	
	if (window.XMLHttpRequest) {
		req = new XMLHttpRequest();
	// branch for IE/Windows ActiveX version
	} else if (window.ActiveXObject) {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	}
	req.onreadystatechange = processCourseReqChange;
	req.open("GET", "core/core.php?cmd=getxml&term=" + termcode, true);
	req.send(null);
}

function processTermReqChange()
{
	if(req.readyState == 4)
	{
		if(req.status == 200)
		{
			response = req.responseXML.documentElement;
			var terms = response.getElementsByTagName('Term');
			termselect = document.getElementById("termlist");
			termselect.remove(0);
			for(var term = 0; term < terms.length; ++term)
			{
				newopt = document.createElement("option");
				newopt.value = terms[term].getAttribute('Code');
				newopt.text = terms[term].getAttribute('Name') + " (" + newopt.value + ")";
				
				if(newopt.value == start_term)
					newopt.selected = true;
				
				try {
					termselect.add(newopt, null);
				} catch(ex) {
					termselect.add(newopt);
				}
			}
			termselect.selectedIndex = termselect.options.length - 1;
			
			if (window.XMLHttpRequest) {
				req = new XMLHttpRequest();
			// branch for IE/Windows ActiveX version
			} else if (window.ActiveXObject) {
				req = new ActiveXObject("Microsoft.XMLHTTP");
			}
			//req.onreadystatechange = processCourseReqChange;
						
			termChange();
		}
		else
		{
			alert("There was a problem retrieving the XML data...\n" + req.statusText);
		}
	}
}

document.getElementById("course-search").value = "Search...";

document.getElementById("course-search").onfocus = function()
{
	this.className = "";
	if(this.value == "Search...")
		this.value = "";
}

document.getElementById("course-search").onblur = function()
{
	if(this.value == "")
	{
		this.className = "default";
		this.value = "Search...";
	}
}

function do_filtering()
{
	var courseselect = document.getElementById('courselist');
	var searchbox = document.getElementById('course-search');
	var closed = document.getElementById('closed-checkbox');
	var cancelled = document.getElementById('cancelled-checkbox');
	var conflicts = document.getElementById('conflicts-checkbox');
	
	// clear out the course select box
	courseClear();	
	
	for(var course = 0; course < courselist_arr.length; ++course)
	{
		courseinfo = courselist_arr[course]['courseinfo'];
		if((searchbox.value == "Search..."
			|| courseinfo.getAttribute('Title').toLowerCase().indexOf(searchbox.value.toLowerCase()) != -1
			|| courseinfo.getAttribute('Instructor1').toLowerCase().indexOf(searchbox.value.toLowerCase()) != -1
			|| courseinfo.getAttribute('CallNumber').indexOf(searchbox.value) != -1
			|| courseinfo.getAttribute('Section').toLowerCase().indexOf(searchbox.value.toLowerCase()) != -1)
		   && (closed.checked || courseinfo.getAttribute('Status') != 'C')
		   && (cancelled.checked || courseinfo.getAttribute('Cancelled') != 'X'))
		{
			try {
				courseselect.add(courselist_arr[course], null);
			} catch(ex) {
				courseselect.add(courselist_arr[course]);
			}
		}
	}
}

var filtering_timeout = 0;

document.getElementById("course-search").onkeyup = function()
{
	clearTimeout(filtering_timeout);
	filtering_timeout = setTimeout('do_filtering();', 200);
}

document.getElementById('closed-checkbox').onchange =
	document.getElementById('cancelled-checkbox').onchange =
	document.getElementById('conflicts-checkbox').onchange = do_filtering;

var start_term = null;

function downloadTerms_callback(term)
{
	if (window.XMLHttpRequest) {
		req = new XMLHttpRequest();
	// branch for IE/Windows ActiveX version
	} else if (window.ActiveXObject) {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	start_term = term;
	
	req.onreadystatechange = processTermReqChange;
	req.open("GET", "core/core.php?cmd=terms", true);
	req.send(null);
}

Persist.init(downloadTerms_callback);