import PySimpleGUI as sg
import psutil

"""
    Another simple Desktop Widget using PySimpleGUI
    This time a RAM indicator.  The Widget is square.  The bottom section will be shaded to 
    represent the total amount of RAM currently in use.
    The % and number of bytes in use is shown on top in text.
    Uses the theme's button color for colors.

    Copyright 2020 PySimpleGUI.org
"""

ALPHA = 0.5
THEME = 'Dark Green 5'
GSIZE = (160, 160)
UPDATE_FREQUENCY_MILLISECONDS = 1 * 1000


def human_size(bytes, units=(' bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB')):
    """ Returns a human readable string reprentation of bytes"""
    return str(bytes) + ' ' + units[0] if bytes < 1024 else human_size(bytes >> 10, units[1:])


sg.theme(THEME)

graph = sg.Graph(GSIZE, (0, 0), GSIZE, key='-GRAPH-', enable_events=True)
layout = [[graph]]

window = sg.Window('RAM Usage', layout, no_titlebar=True, grab_anywhere=True, margins=(0, 0), element_padding=(0, 0), alpha_channel=ALPHA, finalize=True)

while True:  # Event Loop
    # ----------- update the graphics and text in the window ------------
    ram = psutil.virtual_memory()
    rect_height = int(GSIZE[1] * float(ram.percent) / 100)
    rect_id = graph.draw_rectangle((0, rect_height), (GSIZE[0], 0), fill_color=sg.theme_button_color()[1], line_width=0)
    text_id1 = graph.draw_text(f'{int(ram.percent)}%', (GSIZE[0] // 2, GSIZE[1] // 2), font='Any 40', text_location=sg.TEXT_LOCATION_CENTER,
                               color=sg.theme_button_color()[0])
    text_id2 = graph.draw_text(f'{human_size(ram.used)} used', (GSIZE[0] // 2, GSIZE[1] // 4), font='Any 20', text_location=sg.TEXT_LOCATION_CENTER,
                               color=sg.theme_button_color()[0])
    text_id3 = graph.draw_text('❎', (0, 0), font='Any 8', text_location=sg.TEXT_LOCATION_BOTTOM_LEFT, color=sg.theme_button_color()[0])

    event, values = window.read(timeout=UPDATE_FREQUENCY_MILLISECONDS)
    if event == sg.WIN_CLOSED or event == 'Exit':
        break
    if event == '-GRAPH-':  # exit if clicked in the bottom left 20 x 20 pixel area
        if values['-GRAPH-'][0] < 20 and values['-GRAPH-'][1] < 20:
            break
    graph.delete_figure(rect_id)
    graph.delete_figure(text_id1)
    graph.delete_figure(text_id2)
    graph.delete_figure(text_id3)
window.close()