# Copyright 2008 by Wade Brainerd.  
# This file is part of Finance.
#
# Finance is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# Finance is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with Finance.  If not, see <http://www.gnu.org/licenses/>.

# Import standard Python modules.
import logging, os, math, time, copy, json, time, datetime, locale
from gettext import gettext as _

# Set up localization.
locale.setlocale(locale.LC_ALL, '')

# Import PyGTK.
import gobject, pygtk, gtk, pango, cairo

# Import Sugar UI modules.
import sugar.activity.activity
from sugar.graphics import *

# Import activity module
import finance

CHART_HELP = _('The Chart view shows the proportion of your expenses that is in each category.\nYou can categorize transactions in the Register view.')

class ChartScreen(gtk.HBox):
    def __init__(self, activity):
        gtk.HBox.__init__(self)

        self.activity = activity

        self.category_total = {}
        self.sorted_categories = []

        self.area = gtk.DrawingArea()
        self.area.connect('expose-event', self.chart_expose_cb)

        label = gtk.Label()
        label.set_markup('<b>'+_('Debit Categories')+'</b>')

        self.catbox = gtk.VBox()

        box = gtk.VBox()
        box.pack_start(gtk.VBox(), False, False, 40)
        box.pack_start(label, False, False)
        box.pack_start(gtk.HSeparator(), False, False)
        box.pack_start(self.catbox, False, False, 10)
        box.pack_start(gtk.VBox(), True, True)
 
        self.pack_start(self.area, True, True)
        self.pack_start(box, False, False, 40)

        self.show_all()
       
    def build(self):
        # Build the category totals.
        self.category_total = {}
        for t in self.activity.visible_transactions:
            cat = t['category']
            amount = t['amount']
            
            if t['type'] == 'debit':
                if not self.category_total.has_key(cat):
                    self.category_total[cat] = amount
                else: 
                    self.category_total[cat] += amount 

        # Generate a list of names sorted by total.
        self.sorted_categories = self.category_total.keys()
        #self.sorted_categories.sort(lamba a, b: cmp(self.category_total[a], self.category_total[b]))

        # Clear and rebuild the labels box.
        for w in self.catbox.get_children():
            self.catbox.remove(w)

        catgroup = gtk.SizeGroup(gtk.SIZE_GROUP_HORIZONTAL)
        amountgroup = gtk.SizeGroup(gtk.SIZE_GROUP_HORIZONTAL)
        
        for c in self.sorted_categories:
            hbox = gtk.HBox()

            catlabel = gtk.Label()
            catlabel.set_markup(c)
            catgroup.add_widget(catlabel)

            color = finance.get_category_color_str(c)

            amountlabel = gtk.Label()
            amountlabel.set_markup(locale.currency(self.category_total[c]))
            amountgroup.add_widget(amountlabel)

            hbox.pack_start(amountlabel, True, True, 20)
            hbox.pack_start(catlabel, True, True, 20)

            ebox = gtk.EventBox()
            ebox.modify_bg(gtk.STATE_NORMAL, ebox.get_colormap().alloc_color(color))
            ebox.add(hbox)

            self.catbox.pack_end(ebox, False, False, 5)

        self.show_all()

        # Update the help text.
        self.activity.set_help(CHART_HELP)

    def chart_expose_cb(self, widget, event):
        context = widget.window.cairo_create()
        context.rectangle(event.area.x, event.area.y, event.area.width, event.area.height)
        context.clip()

        # Draw pie chart.
        bounds = widget.get_allocation()

        x = bounds.width/2
        y = bounds.height/2
        r = min(bounds.width, bounds.height)/2 - 10 

        total = 0
        for c in self.sorted_categories:
            total += self.category_total[c]

        if total != 0:
            angle = 0.0

            for c in self.sorted_categories:
                slice = 2*math.pi * self.category_total[c] / total
                color = finance.get_category_color(c)
 
                context.move_to(x, y)
                context.arc(x, y, r, angle, angle + slice)
                context.close_path()

                context.set_source_rgb(color[0], color[1], color[2])
                context.fill_preserve()

                context.set_source_rgb(0, 0, 0)
                context.stroke()

                angle += slice