/*
Tim Redfern Jan 2012 tim@eclectronics.org

Animated graphing - Edmund Rice School Ties

see analytics.js example

http://net.tutsplus.com/tutorials/javascript-ajax/an-introduction-to-the-raphael-js-library/

aim for today: have a few items that can be chosen

1) switch items - multiple lines view .. x amount of lines + 'other'
2) animate between views
3) rollover points
4) label axes
*/

var data,raphael,classOfRange,birthplaces,colleges,locations,fields;

var graphData;

var maxPaths;

window.onload = function() {
	loadData();
	createMenu();
	//alert(document.getElementById("holder").offsetWidth+","+document.getElementById("holder").offsetHeight);
	//seems predictable, gives same result in chrome, firefox, mobile safari
	var graph=document.getElementById('graph');
	raphael = new Raphael(graph, graph.offsetWidth, graph.offsetHeight);
	drawGraph();
}

function graphableData(name) {
	//organises a range of data to graph against a variable value
	this.name=name;
	this.data={};
	this.max=0;
	this.addElement = function(element,value) {
		if (element in this.data) {
			if (value in this.data[element]) this.data[element][value]++;
			else this.data[element][value]=1;
		}
		else { 
			this.data[element]={};
			this.data[element][value]=1
		}
		if (this.data[element][value]>this.max) this.max=this.data[element][value];
	}
	this.getElement = function(element) {
		if (element in this.data) return data[element]; //returns an associative array
	}
	this.summary = function() {
		var s= ""+name+": "+Object.keys(this.data).length+" elements, max "+this.max+"\n";
		var k=Object.keys(this.data);
		//s+=k+":";
		for (i in k) {
			s+=k[i]+":";
			var l=Object.keys(this.data[k[i]]);
			for (j in l)	s+=l[j]+"="+this.data[k[i]][l[j]]+",";
			s+="\n";
		}
		return s+"\n";
	}
	
}

function loadData() {
	maxPaths=8;
	//replace with json loader
	fields=["Class size","Location","Birthplace","College","Career"];
	fieldNames=["classSize","location","birthplace","college","career"];
	//basic { name:"Joe", surname:"Murphy",school:"Dublin",classOf:"86",location:"Ireland",email:"joem20156@gmail.com"},
	//extended { name:"Joe", surname:"Murphy",school:"Dublin",classOf:"86",location:"Ireland",email:"joem20156@gmail.com",birthplace:"Ireland",college:"UCD",career:"construction",sports:["soccer","hurling"],nickname:"Virgil"},
	data = [
		{ school:"Dublin",classOf:"86",location:"Ireland",birthplace:"Ireland",college:"UCD",career:"construction",sports:["soccer","hurling"],nickname:"Virgil"},
		{ school:"Dublin",classOf:"87",location:"Ireland",birthplace:"Ireland",college:"NUIG",career:"law",sports:["soccer","gaelic"],nickname:"Con"},
		{ school:"Dublin",classOf:"86",location:"Ireland",birthplace:"Ireland",college:"TCD",career:"teaching",sports:["gaelic","hurling"],nickname:"Morty"},
		{ school:"Dublin",classOf:"88",location:"USA",birthplace:"UK",college:"UL",career:"army",sports:["soccer"],nickname:"Mick"},
		{ school:"Dublin",classOf:"87",location:"Ireland",birthplace:"Ireland",college:"UCD",career:"law",sports:["soccer","gaelic"],nickname:"Johnjoe"},
		{ school:"Dublin",classOf:"86",location:"UK",birthplace:"Ireland",college:"TCD",career:"teaching",sports:["handball","hurling"],nickname:"Mossy"},
		{ school:"Dublin",classOf:"89",location:"USA",birthplace:"UK",college:"UL",career:"army",sports:["soccer"],nickname:"Mick"},
		{ school:"Dublin",classOf:"90",location:"Ireland",birthplace:"Ireland",college:"UCD",career:"law",sports:["soccer","gaelic"],nickname:"Johnjoe"},
		{ school:"Dublin",classOf:"88",location:"Ireland",birthplace:"Ireland",college:"UCC",career:"teaching",sports:["handball","hurling"],nickname:"Mossy"},
		];
	//analyse data to populate menus etc, this may be loaded direct from corresponding server data
	classOfRange={};
	classOfRange.start=3000;
	classOfRange.end=0;
	birthplaces={};
	colleges={};
	locations={};
	for (var i in data) {
		var year = parseInt(data[i].classOf);
		classOfRange.start=Math.min(classOfRange.start,year);
		classOfRange.end=Math.max(classOfRange.end,year);
		if (data[i].birthplace in birthplaces) birthplaces[data[i].birthplace]++;
		else birthplaces[data[i].birthplace]=1;
		if (data[i].college in colleges) colleges[data[i].college]++;
		else colleges[data[i].college]=1;
		if (data[i].location in locations) locations[data[i].location]++;
		else locations[data[i].location]=1;
	}
	
	var numYears=(classOfRange.end-classOfRange.start);
	
	//prepare all data for graphing
	graphData={};
	for (i in fields) graphData[fields[i]]=new graphableData(fields[i]);
	for (var i in data) {
		var yearField
		for (j in fields) {
			if (fields[j]=="Class size") {
				graphData[fields[j]].addElement("Class size",parseInt(data[i].classOf));
			}
			else	graphData[fields[j]].addElement(data[i][fieldNames[j]],parseInt(data[i].classOf));
		}
	}
		
	///* test
	var message="from "+classOfRange.start+" to "+classOfRange.end+"\n";
	for (var i in graphData) message+=graphData[i].summary();
	alert(message);
	//*/
}

function drawGraph() {
	var color = "hsl(" + [.6, .5, .5] + ")";
	var numYears=(classOfRange.end-classOfRange.start);
	var 	gutterX=10,
		gutterY=16;
	//draw grid
	var gridX=(raphael.width-(gutterX*2))/numYears;
	var gridY=(raphael.height-(gutterY*2));
	raphael.drawGrid(gutterX, gutterY, raphael.width-(gutterX*2), raphael.height -(gutterY*2), numYears, 10, "#000");
	//label axis
	var txt = {font: '12px Helvetica, Arial', fill: "#fff"};
	for (var i=0;i<=numYears;i++) raphael.text(gutterX+(i*gridX),raphael.height-gutterY+8,classOfRange.start+i).attr(txt).toBack();
	//construct graph
	var graph = raphael.path().attr({stroke: color, "stroke-width": 4, "stroke-linejoin": "round"}),
	bgGraph = raphael.path().attr({stroke: "none", opacity: .3, fill: color});
	//default graph is 'Class size'
	//find largest class
	var classSize=[];
	for (var i=0;i<=numYears;i++) classSize[i]=0;
	for (var i in data) {
		classSize[parseInt(data[i].classOf)-classOfRange.start]++;
	}
	var classMax=0;
	for (var i in classSize) classMax=Math.max(classMax,classSize[i]);
	var path,bgPath;
	var stepY=(gridY/classMax);
	for (var i=0;i<=numYears;i++) {
		var 	x=gutterX+(i*gridX),
			y=raphael.height-gutterY-(stepY*classSize[i]);
		if (!i) {
			path=["M",x,y,"C",x,y];
			bgPath=["M", gutterX , raphael.height - gutterY, "L", x, y, "C", x, y];
		}
		if (i&&i<numYears-1) {
			var Y0 = Math.round(raphael.height - gutterY -  (stepY*classSize[i-1])),
			X0 = Math.round(gutterX + (gridX * (i - .5))),
			Y2 = Math.round(raphael.height - gutterY -  (stepY*classSize[i+1])),
			X2 = Math.round(gutterX + (gridX * (i + 1.5)));
			var a = getAnchors(X0, Y0, x, y, X2, Y2);
			path = path.concat([a.x1, a.y1, x, y, a.x2, a.y2]);
			bgPath = bgPath.concat([a.x1, a.y1, x, y, a.x2, a.y2]);
		}
	}
	path = path.concat([x, y, x, y]);
	bgPath = bgPath.concat([x, y, x, y, "L", x, raphael.height - gutterY, "z"]);
	graph.attr({path: path});
	bgGraph.attr({path: bgPath});
}

function createMenu() {
	var menu="<select id='select' onchange='doGraph(this.selectedIndex)'>\n";
	for (i in fields) menu+="<option>"+fields[i]+"</option>/n";
	menu+="</select>\n";
	document.getElementById("menus").innerHTML=menu;	
}

function doGraph(which){
	//draw 1 or multiple graphs. animate between items
	//maximum number of graphs
	alert(fields[which]);
}