#!/usr/bin/env python3

from random import randint, shuffle, uniform

import nanogui
from nanogui import BoxLayout, Color, Label, Orientation, Screen, Widget, Window, glfw
from nanogui.nanovg import RGB

from knob import Knob


class KnobsApp(Screen):
    def __init__(self, size=(450, 250)):
        super().__init__(size, "NanoGUI Knobs")
        self.set_background(Color(96, 96, 96, 255))
        self.win = Window(self, "Envelope")
        self.win.set_layout(BoxLayout(Orientation.Horizontal, margin=20, spacing=20))
        self.resize_event(size)

        knobs = (
            ("Attack", 0.0, 0.0, 5.0, "s", 0.01),
            ("Decay", 0.0, 0.0, 5.0, "s", 0.01),
            ("Sustain", 0.0, 0.0, 100.0, "%", 0.01),
            ("Release", 0.0, 0.0, 5.0, "s", 0.01),
        )

        self.knobs = []
        self.entries = []
        self.labels = []

        for i, knobspec in enumerate(knobs):
            box = Widget(self.win)
            box.set_layout(BoxLayout(Orientation.Vertical, spacing=10))

            rgb = [128 + randint(0, 127), randint(0, 127), 64]
            shuffle(rgb)
            knob = Knob(box, *knobspec)
            knob.color = RGB(*rgb)
            knob.value = round(uniform(knob.min_val, knob.max_val), 2)
            self.knobs.append(knob)
            self.entries.append(knob.create_value_entry(box))
            self.labels.append(Label(box, knob.label, font="sans", font_size=20))

        self.draw_all()
        self.set_visible(True)
        self.perform_layout()

    def resize_event(self, size):
        self.win.set_fixed_size(size)
        self.win.set_size(size)
        self.win.center()
        self.win.perform_layout(self.nvg_context())
        super().resize_event(size)
        return True

    def keyboard_event(self, key, scancode, action, modifiers):
        if super().keyboard_event(key, scancode, action, modifiers):
            return True

        if key == glfw.KEY_ESCAPE and action == glfw.PRESS:
            self.set_visible(False)
            return True

        return True

    def __del__(self):
        # callbacks referencing other widgets cause memory leakage at cleanup
        for entry in self.entries:
            entry.set_callback(lambda x: True)
        for entry in self.knobs:
            entry.set_callback(lambda x: True)


if __name__ == "__main__":
    import gc

    nanogui.init()
    app = KnobsApp()
    nanogui.mainloop(refresh=1 / 60.0 * 1000)
    del app
    gc.collect()
    nanogui.shutdown()