import math

from browser import document, html, svg

ray = 100
values = [20,10,30,15,25]

colors = ["C8E0A2", "A6BED1", "E4CC85", "D7D7D7", "90AF97", "698EA8",
        "BFA166", "A8ADB0", "FF6600"]

panel = document["panel"]
legend = None
print(svg.text)
title = svg.text("", x=150, y=25,
    font_size=22, text_anchor="middle",
    style={"stroke": "black"})
panel <= title

paths = {}

def pie_chart():
    global paths, legend
    # clear SVG document
    for child in panel: # iteration on child nodes
        if child != title:
            panel.removeChild(child)

    # zone for legend
    legend = svg.text("", x=350, y=150,
        font_size=20, text_anchor="middle",
        style={"stroke": "black"})
    panel <= legend

    set_title()

    paths = {}
    data = {}
    for i, cell in enumerate(cells):
        data['Item %s' %(i+1)] = float(cell.text)
    style={"fill-opacity": 1,"stroke": "black","stroke-width": 1}
    width = 3.8 * ray
    height = 2.2 * ray
    x_center = 150
    y_center = 160
    x = x_center
    y = y_center - ray
    total = sum(data.values())
    items = list(data.items())
    cumul = 0
    for i, (key, value) in enumerate(items):
        angle1 = 2 * math.pi * cumul
        cumul += float(value) / total
        angle = 2 * math.pi * cumul
        x_end = x_center + ray * math.cos((math.pi / 2) - angle)
        y_end = y_center - ray * math.sin((math.pi / 2) - angle)
        path = "M%s,%s " %(x_center, y_center)
        path += "L%s,%s " %(int(x), int(y))
        if angle - angle1 <= math.pi:
            path += "A%s,%s 0 0,1 " %(ray, ray)
        else:
            path += "A%s,%s 0 1,1 " %(ray, ray)
        path += "%s,%s z" %(int(x_end), int(y_end))
        x, y = x_end, y_end
        color = colors[i % len(colors)]
        style["fill"] = "#" + color
        path = svg.path(d=path, style=style)
        path.bind("mouseover", lambda ev, key=key: show_legend(key))
        path.bind("mouseout", lambda ev, legend=legend: hide_legend(legend))
        panel <= path
        paths[key] = path

def set_title(*args):
    title.text = title_input.value

def show_legend(key):
    legend.text = key

def hide_legend(legend):
    legend.text = ""

def change(rank,offset):
    x = int(cells[int(rank)].text)
    if x + int(offset) >= 0:
        cells[int(rank)].text = x + int(offset)
        pie_chart()

nb_cols = 2
nb_lines = 5

t = html.TABLE()
tb = html.TBODY()

title_input = html.INPUT(value="Pie Chart")
title_input.bind("change", set_title)
tb <= html.TD("Title") + html.TD(title_input, colspan=3)
t <= tb
document["data"] <= t

t = html.TABLE()
tb = html.BODY()
cells = []

for i in range(nb_lines):
    row = html.TR()
    row <= html.TD("Item %s" %(i + 1))
    b_down = html.BUTTON("<")
    b_down.bind("click", lambda ev, x=i: change(x, -1))
    row <= html.TD(b_down)
    cell = html.SPAN(values[i])
    row <= html.TD(cell)
    b_up = html.BUTTON(">")
    b_up.bind("click", lambda ev, x=i: change(x, 1))
    row <= html.TD(b_up)
    cells.append(cell)
    tb <= row
t <= tb
document["data"] <= t

pie_chart()