// TODO - change y axis to dropped
const WIDTH = 800;
const HEIGHT = 600;
const parseTime = d3.timeParse("%B %e, %Y");

let instances;
let xScale, yScale;
let highlighted = []
let courses = []
let metros = []

const randomColor = ()=>{
	const red = Math.floor(Math.random()*128) + 64;
	const green = Math.floor(Math.random()*128) + 64;
	const blue = Math.floor(Math.random()*128) + 64;
	return `rgb(${red}, ${green}, ${blue})`
}

const renderTable = () => {
	let trs = d3.select('tbody')
		.selectAll('tr')
		.data(highlighted, d => d.instance_id)

	trs.exit().remove()

	trs = trs
		.enter()
		.append('tr')
		.style('background-color', datum => datum.color)
	trs.selectAll('td')
		.data(d => [
			d.instance_id, 
			d.course, 
			d.graduation_date, 
			d.total_students, 
			`${d.dropped} (${Math.floor(d.dropped/d.total_students*100)}%)`, 
			d.graduates,
			`${d.ninety_day_outcomes} (${Math.floor(d.ninety_day_outcomes/d.graduates*100)}%)`
		], d => d.instance_id)
		.enter()
		.append('td')
		.text(value => value)

	trs.append('td')
		.append('button')
		.text('Deselect')
		.on('click', (event, datum) =>{
			event.preventDefault();
			delete datum.color
			highlighted = highlighted.filter(i => i.instance_id != datum.instance_id)
			renderPoints()
			renderTable()
		})

}

const renderPoints = () => {
	d3.select('#points')
		.selectAll('circle')
		.data(instances, d => d.id)
		.enter()
		.append('circle');

	d3.selectAll('circle')
		.attr('cy', (datum, index) => yScale(datum.ninety_day_outcomes/datum.graduates*100) )
		.attr('cx', (datum, index) => xScale(parseTime(datum.graduation_date)) )
		.attr('fill', datum => datum.color? datum.color : 'black')
		.attr('r', datum => datum.color? 10 : 5)
		.style('display', (datum)=>{
			const instanceMetro = datum.course.split('-')[0]
			const instanceCourse = datum.course.split('-')[1]
			
			const metro = metros.find(m => m.metro === instanceMetro)
			const course = courses.find(c => c.course === instanceCourse)

			if(metro.checked && course.checked){
				return 'block'
			} else {
				return 'none'
			}
		})
		.on('click', (event, datum) => {
			const found = highlighted.find(i => i.instance_id === datum.instance_id)

			if(found === undefined){
				datum.color = randomColor()
				highlighted.push(datum)
			} else {
				delete datum.color
				highlighted = highlighted.filter(i => i.instance_id != datum.instance_id)
			}
			renderPoints()
			renderTable()
		});

}

const setupGraph = ()=>{
	d3.select('svg');
	d3.select('svg')
		.style('width', WIDTH)
		.style('height', HEIGHT);

	xScale = d3.scaleTime();
	xScale.range([0,WIDTH]);
	const xDomain = d3.extent(instances, (datum, index) => {
		return parseTime(datum.graduation_date);
	});
	xScale.domain(xDomain);

	yScale = d3.scaleLinear();
	yScale.range([HEIGHT, 0]);
	const yDomain = d3.extent(instances, (datum, index) => {
		return datum.ninety_day_outcomes/datum.graduates*100;
	})
	yScale.domain(yDomain);
}

const createAxes = () => {
	const bottomAxis = d3.axisBottom(xScale);
	d3.select('#container')
		.append('g')
		.attr('id', 'x-axis')
		.call(bottomAxis)
		.attr('transform', 'translate(0,'+HEIGHT+')');

	const leftAxis = d3.axisLeft(yScale);
	d3.select('#container')
		.append('g')
		.attr('id', 'y-axis')
		.call(leftAxis);
}

const createFormSubmissionHandler = () => {
	d3.select('form').on('submit', (event)=>{
		event.preventDefault();
		const instanceID = parseInt(d3.select('input[type="text"]').property('value'))
		const found = instances.find(i => i.instance_id === instanceID)
		if(found !== undefined && highlighted.find(instance => instance.instance_id === instanceID) === undefined){
			found.color = randomColor()
			highlighted.push(found);
		}
		renderTable();
		renderPoints();
	});
}

const populateMetrosCoursesCheckboxes = ()=>{

	d3.select('#courses ul')
		.selectAll('li')
		.data(courses)
		.enter()
		.append('li')
		.text(d => d.course)
		.append('input')
	d3.selectAll('#courses ul li input')
		.attr('type', 'checkbox')
		.property('checked', d => d.checked)
		.on('click', (event, datum)=>{
			datum.checked = !datum.checked
			renderPoints()
		})

	d3.select('#metros ul')
		.selectAll('li')
		.data(metros)
		.enter()
		.append('li')
		.text(d => d.metro)
		.append('input')
	d3.selectAll('#metros ul li input')
		.attr('type', 'checkbox')
		.property('checked', d => d.checked)
		.on('click', (event, datum)=>{
			datum.checked = !datum.checked
			renderPoints()
		})

	d3.select('#courses button:nth-child(2)')
		.on('click', ()=>{
			for(course of courses){
				course.checked = true
			}
			renderPoints()
			populateMetrosCoursesCheckboxes()
		})
	d3.select('#courses button:nth-child(3)')
		.on('click', ()=>{
			for(course of courses){
				course.checked = false 
			}
			renderPoints()
			populateMetrosCoursesCheckboxes()
		})

	d3.select('#metros button:nth-child(2)')
		.on('click', ()=>{
			for(metro of metros){
				metro.checked = true
			}
			renderPoints()
			populateMetrosCoursesCheckboxes()
		})
	d3.select('#metros button:nth-child(3)')
		.on('click', ()=>{
			for(metro of metros){
				metro.checked = false 
			}
			renderPoints()
			populateMetrosCoursesCheckboxes()
		})
}

window.onload = async ()=>{
	instances = await d3.json('/instances');
	for(let instance of instances){
		const segments = instance.course.split('-')

		if(metros.find(m => m.metro === segments[0]) === undefined){
			metros.push({ checked:true, metro: segments[0] })
		}

		if(courses.find(c => c.course === segments[1]) === undefined){
			courses.push({ checked:true, course: segments[1] })
		}

	}
	populateMetrosCoursesCheckboxes()
	setupGraph();
	createAxes();
	renderPoints();
	createFormSubmissionHandler();
}