#!/usr/bin/python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2022/08/05 10:04:00 +0900>
"""
xscreensaver by pygame sample.

* Ubuntu Linux 20.04 LTS + Python 2.7.18 + pygame 1.9.3
* xwininfo 1.1.5 (sudo apt install x11-utils)
"""

import os
import sys
import math
import platform
import random
import subprocess
import re

IMG_FILE = "ball_64x64.png"
FPS = 60


class Ball:

    def __init__(self, img, scrw, scrh, t):
        self.img = img
        self.img_w = img.get_width()
        self.img_h = img.get_height()
        self.scrw = scrw
        self.scrh = scrh

        self.x = random.randint(16, scrw - self.img_w - 16)
        self.y = random.randint(16, scrh - self.img_h - 16)

        ang = random.randint(0, 360)
        spd = float(scrw) / t
        self.dx = spd * math.cos(math.radians(ang))
        self.dy = spd * math.sin(math.radians(ang))

    def update(self):
        self.x += self.dx
        self.y += self.dy
        if self.x <= 0 or self.x >= self.scrw - self.img_w:
            self.dx *= -1
        if self.y <= 0 or self.y >= self.scrh - self.img_h:
            self.dy *= -1

    def draw(self, screen):
        screen.blit(self.img, (self.x, self.y))


def main():
    if platform.system() == "Windows":
        os.environ["SDL_VIDEODRIVER"] = "windib"
        print("$SDL_VIDEODRIVER = %s" % os.environ["SDL_VIDEODRIVER"])
    else:
        # Linux or Darwin
        # os.environ["SDL_VIDEODRIVER"] = "x11"
        pass

    if "XSCREENSAVER_WINDOW" in os.environ:
        # xscreensaver
        hwnd = os.environ["XSCREENSAVER_WINDOW"]
        os.environ["SDL_WINDOWID"] = str(int(hwnd, 16))
        # print("$XSCREENSAVER_WINDOW = %s" % os.environ["XSCREENSAVER_WINDOW"])
        # print("$SDL_WINDOWID = %s" % os.environ["SDL_WINDOWID"])

        # get window size using xwininfo
        cmd = ["xwininfo", "-id", os.environ["XSCREENSAVER_WINDOW"]]
        p = subprocess.Popen(
            cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        ret = str(p.communicate())
        size_info = re.search('Width:\s+(\d+)[^H]+Height:\s+(\d+)', ret)
        w, h = size_info.groups()
        scrw = int(w)
        scrh = int(h)
    else:
        # not xscreensaver
        hwnd = None
        scrw, scrh = 512, 256

    import pygame

    # pygame.init()
    pygame.display.init()

    # print("driver = %s" % pygame.display.get_driver())
    # print("pygame.display.get_wm_info()")
    # print(pygame.display.get_wm_info())
    # print("pygame.display.Info()")
    # print(pygame.display.Info())

    screen = pygame.display.set_mode((scrw, scrh))

    # pygame.display.set_caption('xscreensaver by pygame')

    # load image
    base_dir = os.path.realpath(os.path.dirname(__file__))
    file_path = os.path.join(base_dir, IMG_FILE)

    img = pygame.image.load(file_path).convert()
    img.set_colorkey(img.get_at((0, 0)), pygame.RLEACCEL)

    # create balls
    balls = []
    for i in range(16):
        balls.append(Ball(img, scrw, scrh, 60.0 * 3.0))

    clock = pygame.time.Clock()
    looping = True

    while looping:
        # main loop

        # event check
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                looping = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE or event.key == pygame.K_q:
                    looping = False

        if not looping:
            break

        # move balls
        for obj in balls:
            obj.update()

        # fill bg
        screen.fill((0, 0, 0))

        # draw balls
        for obj in balls:
            obj.draw(screen)

        pygame.display.flip()
        clock.tick(FPS)

    pygame.quit()
    sys.exit()


if __name__ == '__main__':
    main()