import os
import sys
from shutil import move, copyfile
from PIL import Image, ImageOps
from shutil import copyfile, rmtree
import numpy as np
import cv2

from_dir = "IMG_1734/"
to_dir = "IMG_1738/"
render_dir = "flowwarp_transfer_cross/"

if os.path.exists(render_dir):
    rmtree(render_dir)

os.makedirs(render_dir)
os.makedirs(render_dir + 'out_fwd_from/')
os.makedirs(render_dir + 'out_rvr_from/')
os.makedirs(render_dir + 'out_fwd_from_rec/')
os.makedirs(render_dir + 'out_rvr_from_rec/')
os.makedirs(render_dir + 'out_fwd_to/')
os.makedirs(render_dir + 'out_rvr_to/')
os.makedirs(render_dir + 'out_fwd_to_rec/')
os.makedirs(render_dir + 'out_rvr_to_rec/')

def warp_flow(img, flow):
  h, w = flow.shape[:2]
  flow = -flow
  flow[:,:,0] += np.arange(w)
  flow[:,:,1] += np.arange(h)[:,np.newaxis]
  res = cv2.remap(img, flow, None, cv2.INTER_LINEAR)
  return res
def load(path):
  pil_image = Image.open(path).convert('RGB')
  im = np.array(pil_image)
  im = im[:, :, ::-1].copy()
  gray = cv2.cvtColor(im, cv2.COLOR_BGR2GRAY)
  return im, gray

def get_files(d):
  return sorted([i.name for i in os.scandir(d) if os.path.isfile(d + i.name) and not i.name.startswith('.') and i.name.endswith('png')])

hsv = []
prev = None
prev_bgr = None
gray = None
prev_gray = None
prev_from = None
prev_fwd_from = None
prev_rvr_from = None
prev_from_gray = None
prev_to = None
prev_fwd_to = None
prev_rvr_to = None
prev_to_gray = None

from_files = get_files(from_dir)
to_files = get_files(to_dir)

for i,from_fn in enumerate(from_files):
  print(from_fn)
  to_fn = to_files[i]

  # load image and convert to grayscale
  from_im, from_gray = load(from_dir + from_fn)
  to_im, to_gray = load(to_dir + to_fn)

  # store first frame
  if prev_from_gray is None:
    prev_fwd_from = from_im
    prev_rvr_from = from_im
    prev_from_gray = from_gray
    prev_fwd_to = to_im
    prev_rvr_to = to_im
    prev_to_gray = to_gray
    #hsv = np.zeros((256,512,3))
    #hsv[...,1] = 255
    continue

  # compute optical flow
  from_fwd_flow = cv2.calcOpticalFlowFarneback(prev_from_gray, from_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)
  #from_rvr_flow = cv2.calcOpticalFlowFarneback(from_gray, prev_from_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)
  #to_fwd_flow = cv2.calcOpticalFlowFarneback(prev_to_gray, to_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)
  #to_rvr_flow = cv2.calcOpticalFlowFarneback(to_gray, prev_to_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)
  #cross_fwd_flow = cv2.calcOpticalFlowFarneback(from_gray, to_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)
  #cross_rvr_flow = cv2.calcOpticalFlowFarneback(to_gray, from_gray, None, 0.5, 3, 15, 3, 5, 1.2, 0)

  #mag, ang = cv2.cartToPolar(flow[...,0], flow[...,1])
  #hsv[...,0] = ang * 180 / np.pi / 2
  #hsv[...,2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_L2)
  #bgr = cv2.cvtColor(hsv.astype('uint8'), cv2.COLOR_HSV2BGR)

  #if prev_bgr is None:
  #  prev_bgr = np.copy(bgr)
  #  continue

  #if (i % 10) == 3:
  #  wd = "test/"
  #elif (i % 10) == 6:
  #  wd = "val/"
  #else:
  #  wd = "train/"

  fwd_flow = from_fwd_flow
  #rvr_flow = from_rvr_flow
  out_fwd_from = warp_flow(from_im, fwd_flow)
  out_fwd_from_rec = warp_flow(prev_fwd_from, fwd_flow)
  out_fwd_to = warp_flow(to_im, fwd_flow)
  out_fwd_to_rec = warp_flow(prev_fwd_to, fwd_flow)

  #out_rvr_from = warp_flow(from_im, rvr_flow)
  #out_rvr_from_rec = warp_flow(prev_rvr_from, rvr_flow)
  #out_rvr_to = warp_flow(to_im, rvr_flow)
  #out_rvr_to_rec = warp_flow(prev_rvr_to, rvr_flow)

  ren = "frame_{:05d}.png".format(i)
  #cv2.imwrite(render_dir + "A/" + wd + ren, prev_bgr)
  #cv2.imwrite(render_dir + "B/" + wd + ren, bgr)
  cv2.imwrite(render_dir + "out_fwd_from/" + ren, out_fwd_from)
  cv2.imwrite(render_dir + "out_fwd_from_rec/" + ren, out_fwd_from_rec)
  cv2.imwrite(render_dir + "out_fwd_to/" + ren, out_fwd_to)
  cv2.imwrite(render_dir + "out_fwd_to_rec/" + ren, out_fwd_to_rec)
  #cv2.imwrite(render_dir + "out_rvr_from/" + ren, out_rvr_from)
  #cv2.imwrite(render_dir + "out_rvr_from_rec/" + ren, out_rvr_from_rec)
  #cv2.imwrite(render_dir + "out_rvr_to/" + ren, out_rvr_to)
  #cv2.imwrite(render_dir + "out_rvr_to_rec/" + ren, out_rvr_to_rec)
  #cv2.imwrite(render_dir + "next/" + ren, out_next)
  # copyfile(work_dir + fn, render_dir + "B/" + wd + ren)

  prev_from_gray = from_gray
  prev_to_gray = to_gray
  if i > 3:
    prev_fwd_from = out_fwd_from_rec
    prev_fwd_to = out_fwd_to_rec
    #prev_rvr_from = out_rvr_from_rec
    #prev_rvr_to = out_rvr_to_rec
  #prev_bgr = np.copy(bgr)