#
# graph.py
#
# Copyright (C) 2009 Ian Martin <ianmartin@cantab.net>
# Copyright (C) 2008 Damien Churchill <damoxc@gmail.com>
# Copyright (C) 2008 Martijn Voncken <mvoncken@gmail.com>
# Copyright (C) Marcos Pinto 2007 <markybob@gmail.com>
#
# Deluge is free software.
#
# You may 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.
#
# deluge 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 deluge.    If not, write to:
# 	The Free Software Foundation, Inc.,
# 	51 Franklin Street, Fifth Floor
# 	Boston, MA    02110-1301, USA.
#
#    In addition, as a special exception, the copyright holders give
#    permission to link the code of portions of this program with the OpenSSL
#    library.
#    You must obey the GNU General Public License in all respects for all of
#    the code used other than OpenSSL. If you modify file(s) with this
#    exception, you may extend this exception to your version of the file(s),
#    but you are not obligated to do so. If you do not wish to do so, delete
#    this exception statement from your version. If you delete this exception
#    statement from all source files in the program, then also delete it here.

"""
port of old plugin by markybob.
"""
import time
import math
import cairo
from deluge.log import LOG as log
from deluge.ui.client import client

white = (0, 0, 0)
gray = (0.75, 0.75, 0.75)
black = (1.0, 1.0, 1.0)
darkred = (0.65, 0, 0)
red = (1.0, 0, 0)
green = (0, 1.0, 0)
blue = (0, 0, 1.0)
orange = (1.0, 0.74, 0)

def default_formatter(value):
    return str(value)

def size_formatter_scale(value):
    scale = 1.0
    for i in range(0,3):
        scale = scale * 1024.0
        if value / scale < 1024:
            return scale

def change_opacity(color, opactiy):
    """A method to assist in changing the opactiy of a color inorder to draw the
    fills.
    """
    color = list(color)
    if len(color) == 4:
        color[3] = opactiy
    else:
        color.append(opactiy)
    return tuple(color)

class Graph:
    def __init__(self):
        self.width = 100
        self.height = 100
        self.length = 150
        self.stat_info = {}
        self.line_size = 2
        self.dash_length = [10]
        self.mean_selected = True
        self.legend_selected = True
        self.max_selected = True
        self.black = (0, 0 , 0,)
        self.interval = 2 # 2 secs
        self.text_bg =  (255, 255 , 255, 128) # prototyping
        self.set_left_axis()

    def set_left_axis(self, **kargs):
        self.left_axis = kargs

    def add_stat(self, stat, label='', axis='left', line=True, fill=True, color=None):
        self.stat_info[stat] = {
            'axis': axis,
            'label': label,
            'line': line,
            'fill': fill,
            'color': color
            }

    def set_stats(self, stats):
        self.last_update = stats["_last_update"]
        del stats["_last_update"]
        self.length = stats["_length"]
        del stats["_length"]
        self.interval = stats["_update_interval"]
        del stats["_update_interval"]
        self.stats = stats
        return

  #  def set_config(self, config):
  #      self.length = config["length"]
  #      self.interval = config["update_interval"]

    def set_interval(self, interval):
        self.interval = interval

    def draw_to_context(self, context, width, height):
        self.ctx = context
        self.width, self.height = width, height
        self.draw_rect(white, 0, 0, self.width, self.height)
        self.draw_graph()
        return self.ctx

    def draw(self, width, height):
        surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
        ctx = cairo.Context(surface)
        self.draw_to_context(ctx, width, height)
        return surface


    def draw_x_axis(self, bounds):
        (left, top, right, bottom) = bounds
        duration = self.length * self.interval
        start = self.last_update - duration
        ratio = (right - left) / float(duration)

        if duration < 1800 * 10:
            #try rounding to nearest 1min, 5mins, 10mins, 30mins
            for step in [60, 300, 600, 1800]:
                if duration / step < 10:
                    x_step = step
                    break
        else:
        # if there wasnt anything useful find a nice fitting hourly divisor
            x_step = ((duration / 5) /3600 )* 3600

        #this doesnt allow for dst and timezones...
        seconds_to_step = math.ceil(start/float(x_step)) * x_step - start

        for i in xrange(0, duration/x_step + 1):
            text = time.strftime('%H:%M', time.localtime(start + seconds_to_step  + i*x_step))
            # + 0.5 to allign x to nearest pixel
            x = int(ratio * (seconds_to_step + i*x_step) + left) + 0.5
            self.draw_x_text(text, x, bottom)
            self.draw_dotted_line(gray, x, top-0.5, x, bottom+0.5)

        self.draw_line(gray, left, bottom+0.5, right, bottom+0.5)

    def draw_graph(self):
        font_extents = self.ctx.font_extents()
        x_axis_space = font_extents[2] + 2 + self.line_size / 2.0
        plot_height = self.height - x_axis_space
        #lets say we need 2n-1*font height pixels to plot the y ticks
        tick_limit = (plot_height / font_extents[3] )# / 2.0

        max_value = 0
        for stat in self.stat_info:
            if self.stat_info[stat]['axis'] == 'left':
                try:
                    l_max =  max(self.stats[stat])
                except ValueError:
                    l_max = 0
                if l_max > max_value:
                    max_value = l_max
        if max_value < self.left_axis['min']:
            max_value = self.left_axis['min']

        y_ticks = self.intervalise(max_value, tick_limit)
        max_value = y_ticks[-1]
        #find the width of the y_ticks
        y_tick_text = [self.left_axis['formatter'](tick) for tick in y_ticks]
        def space_required(text):
            te = self.ctx.text_extents(text)
            return math.ceil(te[4] - te[0])
        y_tick_width = max((space_required(text) for text in y_tick_text))

        top = font_extents[2] / 2.0
        #bounds(left, top, right, bottom)
        bounds = (y_tick_width + 4, top + 2,  self.width, self.height - x_axis_space)

        self.draw_x_axis(bounds)
        self.draw_left_axis(bounds, y_ticks, y_tick_text)

    def intervalise(self, x, limit=None):
        """Given a value x create an array of tick points to got with the graph
        The number of ticks returned can be constrained by limit, minimum of 3
        """
    #Limit is the number of ticks which is 1 + the number of steps as we
    #count the 0 tick in limit
        if limit is not None:
            if limit <3:
                limit = 2
            else:
                limit = limit -1
        scale = 1
        if 'formatter_scale' in self.left_axis:
            scale = self.left_axis['formatter_scale'](x)
            x = x / float(scale)

    #Find the largest power of 10 less than x
        log = math.log10(x)
        intbit = math.floor(log)

        interval = math.pow(10, intbit)
        steps =  int(math.ceil(x / interval))

        if steps <= 1 and (limit is None or limit >= 10*steps):
            interval = interval * 0.1
            steps = steps * 10
        elif steps <= 2 and (limit is None or limit >= 5*steps):
            interval = interval * 0.2
            steps = steps * 5
        elif steps <=5 and (limit is None or limit >= 2*steps):
            interval = interval * 0.5
            steps = steps * 2

        if limit is not None and steps > limit:
            multi = steps / float(limit)
            if multi > 2:
                interval = interval * 5
            else:
                interval = interval * 2

        intervals = [i * interval * scale for  i in xrange(1+int(math.ceil(x/ interval)))]
        return intervals

    def draw_left_axis(self, bounds, y_ticks, y_tick_text):
        (left, top, right, bottom) = bounds
        stats = {}
        for stat in self.stat_info:
            if self.stat_info[stat]['axis'] == 'left':
                stats[stat] = self.stat_info[stat]
                stats[stat]['values'] = self.stats[stat]
                stats[stat]['fill_color'] = change_opacity(stats[stat]['color'], 0.5)
                stats[stat]['color'] = change_opacity(stats[stat]['color'], 0.8)

        height =  bottom - top
        max_value = y_ticks[-1]
        ratio = height / max_value

        for i, y_val in enumerate(y_ticks):
            y = int(bottom - y_val * ratio ) - 0.5
            if i != 0:
                self.draw_dotted_line(gray, left, y, right, y)
            self.draw_y_text(y_tick_text[i], left, y)
        self.draw_line(gray, left, top, left, bottom)

        for stat, info in stats.iteritems():
            if len(info['values']) > 0:
                self.draw_value_poly(info['values'], info['color'], max_value, bounds)
                self.draw_value_poly(info['values'], info['fill_color'], max_value, bounds, info['fill'])

    def draw_legend(self):
        pass


    def trace_path(self, values, max_value, bounds):
        (left, top, right, bottom) = bounds
        ratio = (bottom - top) / max_value
        line_width = self.line_size

        self.ctx.set_line_width(line_width)
        self.ctx.move_to(right, bottom)

        self.ctx.line_to(right, int(bottom -  values[0] * ratio ))

        x = right
        step = (right - left) / float(self.length -1)
        for i, value in enumerate(values):
            if i == self.length - 1:
                x = left

            self.ctx.line_to(x, int(bottom - value * ratio))
            x -= step

        self.ctx.line_to(
            int(right  - (len(values) - 1) * step),
            bottom)
        self.ctx.close_path()


    def draw_value_poly(self, values, color, max_value, bounds, fill=False):
        self.trace_path(values, max_value, bounds)
        self.ctx.set_source_rgba(*color)

        if fill:
            self.ctx.fill()
        else:
            self.ctx.stroke()

    def draw_x_text(self, text, x, y):
        """Draws text below and horizontally centered about x,y"""
        fe = self.ctx.font_extents()
        te = self.ctx.text_extents(text)
        height = fe[2]
        x_bearing = te[0]
        width = te[2]
        self.ctx.move_to(int(x - width/2.0 + x_bearing), int(y + height))
        self.ctx.set_source_rgba(*self.black)
        self.ctx.show_text(text)

    def draw_y_text(self, text, x, y):
        """Draws text left of and vertically centered about x,y"""
        fe = self.ctx.font_extents()
        te = self.ctx.text_extents(text)
        descent = fe[1]
        ascent = fe[0]
        x_bearing = te[0]
        width = te[4]
        self.ctx.move_to(int(x - width - x_bearing - 2), int(y + (ascent - descent)/2.0))
        self.ctx.set_source_rgba(*self.black)
        self.ctx.show_text(text)

    def draw_rect(self, color, x, y, height, width):
        self.ctx.set_source_rgba(*color)
        self.ctx.rectangle(x, y, height, width)
        self.ctx.fill()

    def draw_line(self, color, x1, y1, x2, y2):
        self.ctx.set_source_rgba(*color)
        self.ctx.set_line_width(1)
        self.ctx.move_to(x1, y1)
        self.ctx.line_to(x2, y2)
        self.ctx.stroke()

    def draw_dotted_line(self, color, x1, y1, x2, y2):
        self.ctx.set_source_rgba(*color)
        self.ctx.set_line_width(1)
        dash, offset = self.ctx.get_dash()
        self.ctx.set_dash(self.dash_length, 0)
        self.ctx.move_to(x1, y1)
        self.ctx.line_to(x2, y2)
        self.ctx.stroke()
        self.ctx.set_dash(dash, offset)

if __name__ == "__main__":
    import test