import cv2
from PIL import ImageGrab
import numpy as np
import argparse
import time
 
global img
global point1, point2
 
def on_mouse(event, x, y, flags, param):
  global img, point1, point2
  img2 = img.copy()
  if event == cv2.EVENT_LBUTTONDOWN: # 左键点击
    point1 = (x, y)
    cv2.circle(img2, point1, 10, (0, 255, 0), thickness=2)
    cv2.imshow('image', img2)
  elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON): # 按住左键拖曳
    cv2.rectangle(img2, point1, (x, y), (255, 0, 0), thickness=2)
    cv2.imshow('image', img2)
  elif event == cv2.EVENT_LBUTTONUP: # 左键释放
    point2 = (x, y)
    cv2.rectangle(img2, point1, point2, (0, 0, 255), thickness=2)
    cv2.imshow('image', img2)
 
def select_roi(frame):
  global img, point1, point2
  img = cv2.cvtColor(np.array(frame), cv2.COLOR_RGB2BGR)
  winname = 'image'
  cv2.namedWindow(winname, cv2.WINDOW_NORMAL)
  cv2.setWindowProperty(winname, cv2.WND_PROP_FULLSCREEN, cv2.WINDOW_FULLSCREEN)
  cv2.setMouseCallback(winname, on_mouse)
  cv2.imshow(winname, img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  return point1, point2
 
if __name__ == '__main__':
  parser = argparse.ArgumentParser()
  parser.add_argument('--fps', type=int, default=10, help='frame per second')
  parser.add_argument('--total_time', type=int, default=15, help='video total time')
  parser.add_argument('--savename', type=str, default='video.mp4', help='save file name')
  parser.add_argument('--screen_type', default=1, type=int, choices=[0, 1], help='1: full screen, 0: region screen')
  args = parser.parse_args()
 
  print('等到3秒，请切换到录屏的页面')
  if args.screen_type==0:
    print('Press Esc to close window')
  time.sleep(3)
 
  curScreen = ImageGrab.grab() # 获取屏幕对象
  if args.screen_type:
    height, width = curScreen.size
    min_x, min_y, max_x, max_y = 0, 0, width, height
    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    video = cv2.VideoWriter(args.savename, fourcc, args.fps, (height, width))
  else:
    point1, point2 = select_roi(curScreen)
    min_x = min(point1[0], point2[0])
    min_y = min(point1[1], point2[1])
    max_x = max(point1[0], point2[0])
    max_y = max(point1[1], point2[1])
    height, width = max_y - min_y, max_x - min_x
    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    video = cv2.VideoWriter(args.savename, fourcc, args.fps, (width, height))
 
  imageNum = 0
  while True:
    imageNum += 1
    captureImage = ImageGrab.grab() # 抓取屏幕
    frame = cv2.cvtColor(np.array(captureImage), cv2.COLOR_RGB2BGR)
    if args.screen_type==0:
      frame = frame[min_y:max_y, min_x:max_x, :]
    
    if imageNum < args.fps * args.total_time:
      video.write(frame)
    # 退出条件
    if cv2.waitKey(50) == ord('q') or imageNum > args.fps * args.total_time:
      break
  video.release()
  cv2.destroyAllWindows()