# -*- coding: utf-8 -*-
import glfw
import OpenGL.GL as gl

import imgui as im
from imgui.integrations.glfw import GlfwRenderer

from PIL import Image
import numpy as np

def load_texture(filename):
    image = Image.open(filename)
    width, height = image.size
    texture_id = gl.glGenTextures(1)
    gl.glBindTexture(gl.GL_TEXTURE_2D, texture_id)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER, gl.GL_LINEAR)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER, gl.GL_LINEAR)
    gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_RGBA, width, height, 0, gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, np.array(image.convert("RGBA")).flatten())
    return texture_id

class ImguiWindow():
    def impl_glfw_init(self, w, h):
        window_name = "minimal Imgui/GLFW3 example"

        if not glfw.init():
            print("Could not initialize OpenGL context")
            exit(1)

        # OS X supports only forward-compatible core profiles from 3.2
        glfw.window_hint(glfw.CONTEXT_VERSION_MAJOR, 3)
        glfw.window_hint(glfw.CONTEXT_VERSION_MINOR, 3)
        glfw.window_hint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)

        glfw.window_hint(glfw.OPENGL_FORWARD_COMPAT, gl.GL_TRUE)

        # Create a windowed mode window and its OpenGL context
        window = glfw.create_window(
            int(w), int(h), window_name, None, None
        )
        glfw.make_context_current(window)

        if not window:
            glfw.terminate()
            print("Could not initialize Window")
            exit(1)

        return window

    def __init__(self, init_fn, draw_fn, window_name, width, height):
        im.create_context()

        self.window = self.impl_glfw_init(width, height)
        impl = GlfwRenderer(self.window)

        # Load a new font
        io = im.get_io()
        new_font = io.fonts.add_font_from_file_ttf("./fira.ttf", 24)
        impl.refresh_font_texture()

        init_fn()

        while not glfw.window_should_close(self.window):
            glfw.poll_events()
            impl.process_inputs()

            im.new_frame()

            with im.font(new_font):
                draw_fn()

            gl.glClearColor(1., 1., 1., 1)
            gl.glClear(gl.GL_COLOR_BUFFER_BIT)

            im.render()
            impl.render(im.get_draw_data())
            glfw.swap_buffers(self.window)

        impl.shutdown()
        glfw.terminate()