from svg.charts import pie
import math
from lxml import etree

def createPie(data, gaps = 0):
	total = sum(data.values())
	colours = ['#268ED7','#6A4F8D', '#A03D4F','#DC7432','#F6DC3B','#76B33B', '#267B60']
	className = "hoverTitles" if len(data) > 9 else ""
	svg = '<svg viewBox="-115 -115 230 230" xmlns="http://www.w3.org/2000/svg" class="%s">' % className
	numbers = ""
	position = 90
	i = 0

	for e in sorted(data.keys()):
		data[e] = data[e] / total

		arc = data[e] * 360.;
		diff = polarToCartesian(0,0,5, position+0.5*arc) if gaps > 0 else {'x':0, 'y': 0}
		d = describeArc(float(diff['x']), float(diff['y']), 60, position, position+arc)
		# print(position, arc)
		svg += '<path fill="none" stroke="%s" stroke-width="60" d="%s" />' % (colours[i%len(colours)], d)
		# tRadius = 105 if i%2 else 95
		t = polarToCartesian(0,0, 100, position+0.5*arc)
		svg += '<text x="%s" y="%s" font-family="sans-serif" font-size="12" style=" stroke:color: black;" text-anchor="middle" transform="rotate(%s %s,%s)">%s</text>' % (t['x'], t['y'], position+0.5*arc, t['x'],t['y'], e)
		position += arc
		i+=1

	svg += numbers
	svg += "</svg>"
	return svg
	# data is now in fractions
	
def polarToCartesian(centerX, centerY, radius, angleInDegrees):
	"""
	Adapted from http://stackoverflow.com/a/18473154
	"""
	angleInRadians = (angleInDegrees - 90) * math.pi / 180.0;

	return {
		"x": str(centerX + (radius * math.cos(angleInRadians))),
		"y": str(centerY + (radius * math.sin(angleInRadians)))
	}

def describeArc(x, y, radius, startAngle, endAngle):
	"""
	Adapted from http://stackoverflow.com/a/18473154
	"""
	start = polarToCartesian(x, y, radius, endAngle)
	end = polarToCartesian(x, y, radius, startAngle)

	largeArcFlag = "0" if endAngle - startAngle <= 180 else "1";

	d = " ".join([
		"M", start['x'], str(round(float(start['y']) - 0.0001,4)), # make sure we don't get crazy small number IE cannot handle
		"A", str(radius), str(radius), "0", largeArcFlag, "0", end['x'], end['y']
	]);

	return d


	# g = pie.Pie({})
	# options = dict(
	# 	width=640,
	# 	height=480,
	# 	fields=list(data.keys()),
	# 	graph_title='Question 7',
	# 	# expand_greatest = True,
	# 	show_data_labels = True,
	# 	compress=False,
	# 	css_inline=True,
	# )
	# g.__dict__.update(options)
	# g.add_data({'data': list(data.values()), 'title': 'Female'})
	# # g.add_data({'data': [0, 2, 1, 5, 4], 'title': 'Male'})
	# return str(g.burn())