import enum
import math
import cairo

from hexagram.dial import Dial

class Tacho(Dial):
    __slots__ = 'units',

    MIN_ANGLE = 232.0 * (math.pi / 180.0)
    MAX_ANGLE = 488.0 * (math.pi / 180.0)

    FONT_FACE = "Muli"

    def __init__(self, x: float, y: float, radius: float, max_value: float):
        super().__init__(x, y, radius, self.MIN_ANGLE, self.MAX_ANGLE, max_value)

    def draw_number(self, cr: cairo.Context, radius: float, value: float, text: str):
        scale = value / self.max_value
        angle = self.min_angle + ((self.max_angle - self.min_angle) * scale) - Dial.ANGLE_OFFSET

        cr.set_source_rgb(1, 1, 1)
        cr.move_to(self.x + radius * self.radius * math.cos(angle) -  8,
                   self.y + radius * self.radius * math.sin(angle) + 15)

        cr.show_text(text)
        cr.stroke()

    def draw_bg(self, cr: cairo.Context):
        super().draw_bg(cr)

        cr.select_font_face(self.FONT_FACE,
                            cairo.FontSlant.ITALIC,
                            cairo.FontWeight.BOLD)

        cr.set_font_size(self.radius * 0.15)
        cr.set_source_rgb(1, 1, 1)

        for speed in range(0, int(self.max_value)+1, 1000):
            self.draw_number(cr, 0.78, speed, "%d" % int(speed / 1000))