import math
import time
import cairo

from gi.repository import Gtk, GLib


# studio clock that displays a clock like mentioned in:
# https://masterbase.at/studioclock/#C3CD2D
class StudioClock(Gtk.ToolItem):
    __gtype_name__ = 'StudioClock'

    # set resolution of the update timer in seconds
    timer_resolution = 0.1

    # init widget
    def __init__(self):
        super().__init__()
        # suggest size of widget
        self.set_size_request(130, 50)
        # remember last drwn time
        self.time = time.localtime(0)
        # set up timeout for periodic redraw
        GLib.timeout_add_seconds(self.timer_resolution, self.do_timeout)

    def do_timeout(self):
        # get current time
        t = time.localtime(time.time())
        # if time did not change since last redraw
        if self.time != t:
            self.time = t
            self.queue_draw()
        # just come back
        GLib.timeout_add_seconds(self.timer_resolution, self.do_timeout)

    # override drawing of the widget
    def do_draw(self, cr):
        # get actual widget size
        width = self.get_allocated_width()
        height = self.get_allocated_height()
        # calculate center and radius of the clock
        center = (width / 2, height / 2)
        radius = min(center)
        # setup gradients for clock background to get a smooth border
        bg_lg = cairo.RadialGradient(
            center[0], center[1], 0, center[0], center[1], radius)
        bg_lg.add_color_stop_rgba(0.0, 0, 0, 0, 1.0)
        bg_lg.add_color_stop_rgba(0.9, 0, 0, 0, 1.0)
        bg_lg.add_color_stop_rgba(1.0, 0, 0, 0, 0.0)
        # paint background
        cr.set_source(bg_lg)
        cr.arc(center[0], center[1], radius, 0, 2 * math.pi)
        cr.fill()
        # draw ticks for every second
        for tick in range(0, 60):
            # fade out seconds in future and highlight past seconds
            if tick > self.time.tm_sec:
                cr.set_source_rgb(0.2, 0.3, 0.01)
            else:
                cr.set_source_rgb(0.764, 0.804, 0.176)
            # calculate tick position
            angle = tick * math.pi / 30
            pos = (center[0] + math.sin(angle) * radius * 0.8,
                   center[1] - math.cos(angle) * radius * 0.8)
            # draw tick
            cr.arc(pos[0], pos[1], radius / 40, 0, 2 * math.pi)
            cr.fill()
        # draw persistant ticks every five seconds
        cr.set_source_rgb(0.764, 0.804, 0.176)
        for tick in range(0, 12):
            # calculate tick position
            angle = tick * math.pi / 6
            pos = (center[0] + math.sin(angle) * radius * 0.9,
                   center[1] - math.cos(angle) * radius * 0.9)
            # draw tick
            cr.arc(pos[0], pos[1], radius / 40, 0, 2 * math.pi)
            cr.fill()
        # set a reasonable font size
        cr.set_font_size(cr.user_to_device_distance(0, height / 5)[1])
        # format time into a string
        text = time.strftime("%H:%M")
        # get text drawing extents
        (xbearing, ybearing,
         textwidth, textheight,
         xadvance, yadvance) = cr.text_extents(text)
        # draw time
        cr.move_to(center[0] - textwidth / 2, center[1] + textheight / 2)
        cr.show_text(text)
