import sys
import cv2
import numpy as np
import math

def image_resize(image, width = None, height = None, inter = cv2.INTER_AREA):
    dim = None
    (h, w) = image.shape[:2]

    if width is None and height is None:
        return image

    if width is None:
        r = height / float(h)
        dim = (int(w * r), height)
    else:
        r = width / float(w)
        dim = (width, int(h * r))
    resized = cv2.resize(image, dim, interpolation = inter)

    return resized

def display (image) :
	resized = image_resize(image, 800, 800)
	cv2.imshow('img', resized)
	
	while cv2.getWindowProperty('img', cv2.WND_PROP_VISIBLE) > 0:
		key = cv2.waitKey(0)
		if key == 27:
			cv2.destroyAllWindows()
			break
	exit(0)

def get_center (contour) : 
	M = cv2.moments(contour)
	cX = int(M["m10"] / M["m00"])
	cY = int(M["m01"] / M["m00"])
	return cX, cY

def draw_line (image, hps, a, b) :
	print(f'{a} -> {b}')
	lA = (hps[a-1]['x'], hps[a-1]['y'])
	lB = (hps[b-1]['x'], hps[b-1]['y'])
	cv2.line(image, lA, lB, [0, 255, 0], 10)
	return (lA, lB)

def horiz_angle (line, rotate = 0) :
	deltaY = line[1][1] - line[0][1] #P2_y - P1_y
	deltaX = line[1][0] - line[0][0] #P2_x - P1_x

	angleInDegrees = normalize_angle(math.degrees(math.atan2(deltaY, deltaX) + rotate))
	return angleInDegrees

def verts_angle (line) :
	angleInDegrees = normalize_angle(horiz_angle(line, math.pi/2))
	return angleInDegrees

def is_close (point, points) :
	for pt in points :
		if math.dist(point, pt) < 100 :
			return True
	return False

# taken from
# https://gist.github.com/phn/1111712/35e8883de01916f64f7f97da9434622000ac0390
def normalize_angle (num, lower=0.0, upper=360.0, b=False):
    """Normalize number to range [lower, upper) or [lower, upper].
    Parameters
    ----------
    num : float
        The number to be normalized.
    lower : float
        Lower limit of range. Default is 0.0.
    upper : float
        Upper limit of range. Default is 360.0.
    b : bool
        Type of normalization. See notes.
    Returns
    -------
    n : float
        A number in the range [lower, upper) or [lower, upper].
    Raises
    ------
    ValueError
      If lower >= upper.
    Notes
    -----
    If the keyword `b == False`, the default, then the normalization
    is done in the following way. Consider the numbers to be arranged
    in a circle, with the lower and upper marks sitting on top of each
    other. Moving past one limit, takes the number into the beginning
    of the other end. For example, if range is [0 - 360), then 361
    becomes 1. Negative numbers move from higher to lower
    numbers. So, -1 normalized to [0 - 360) becomes 359.
    If the keyword `b == True` then the given number is considered to
    "bounce" between the two limits. So, -91 normalized to [-90, 90],
    becomes -89, instead of 89. In this case the range is [lower,
    upper]. This code is based on the function `fmt_delta` of `TPM`.
    Range must be symmetric about 0 or lower == 0.
    Examples
    --------
    >>> normalize(-270,-180,180)
    90
    >>> import math
    >>> math.degrees(normalize(-2*math.pi,-math.pi,math.pi))
    0.0
    >>> normalize(181,-180,180)
    -179
    >>> normalize(-180,0,360)
    180
    >>> normalize(36,0,24)
    12
    >>> normalize(368.5,-180,180)
    8.5
    >>> normalize(-100, -90, 90, b=True)
    -80.0
    >>> normalize(100, -90, 90, b=True)
    80.0
    >>> normalize(181, -90, 90, b=True)
    -1.0
    >>> normalize(270, -90, 90, b=True)
    -90.0
    """
    # abs(num + upper) and abs(num - lower) are needed, instead of
    # abs(num), since the lower and upper limits need not be 0. We need
    # to add half size of the range, so that the final result is lower +
    # <value> or upper - <value>, respectively.
    res = num
    if not b:
        if lower >= upper:
            raise ValueError("Invalid lower and upper limits: (%s, %s)" %
                             (lower, upper))

        res = num
        if num > upper or num == lower:
            num = lower + abs(num + upper) % (abs(lower) + abs(upper))
        if num < lower or num == upper:
            num = upper - abs(num - lower) % (abs(lower) + abs(upper))

        res = lower if res == upper else num
    else:
        total_length = abs(lower) + abs(upper)
        if num < -total_length:
            num += math.ceil(num / (-2 * total_length)) * 2 * total_length
        if num > total_length:
            num -= math.floor(num / (2 * total_length)) * 2 * total_length
        if num > upper:
            num = total_length - num
        if num < lower:
            num = -total_length - num

        res = num * 1.0  # Make all numbers float, to be consistent

    return res

def mean (lst):
    return sum(lst) / len(lst)

def find_hole_punches (img) :
	left=-1
	right=-1
	top=-1
	bottom=-1

	if orientation :
		left = width * 0.2
		right = width * 0.8
	else :
		top = height * 0.2
		bottom = height * 0.8

	gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
	blur = cv2.medianBlur(gray, 31)
	ret, thresh = cv2.threshold(blur, 200, 255, cv2.THRESH_BINARY)
	canny = cv2.Canny(thresh, 75, 200)
	contours, hierarchy = cv2.findContours(canny, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

	contourList = []
	areaList = []
	for contour in contours:
		approx = cv2.approxPolyDP(contour, 0.03 * cv2.arcLength(contour, True), True)
		if cv2.isContourConvex(approx) :
			cX, cY = get_center(contour)
			if (orientation and ( cX < left or cX > right) ) or ( not orientation and ( cY < top or cY > bottom)) :
				area = cv2.contourArea(contour)
				areaList.append(area)
				contourList.append(contour)

	maxArea=0
	maxIndex=0

	#reduce to lambda
	for i in range(len(areaList)) :
		area = areaList[i]
		if area > maxArea:
			maxArea = area
			maxIndex = i

	count = 0
	holePunches = []
	centers = []
	areaRange = 0
	topLeft = None
	minDist = 1000000

	# pretty good
	# add position constraint

	while count < 6 :
		areaRange+=1
		for i in range(len(areaList)) :
			area = areaList[i]
			if area == maxArea or area * ((100 + areaRange) / 100) > maxArea  :
				cX, cY = get_center(contourList[i])
				if is_close((cX, cY), centers) :
					continue
				centers.append((cX, cY))
				print(f'{cX},{cY}')
				hp = {
					'x' : cX,
					'y' : cY,
					'contour' : contourList[i],
					'dist' : math.dist((cX, cY), (0, 0)),
					'order': -1
				}
				if hp['dist'] < minDist :
					minDist = hp['dist']
					topLeft = hp
				holePunches.append(hp)
				count+=1

	for hp in holePunches :
		hp['dist'] = math.dist( (topLeft['x'], topLeft['y']), (hp['x'], hp['y']) )

	print(f'Hole punches: {len(holePunches)}')
	print(f'Found hole punches within {areaRange}% of largest')

	if len(holePunches) != 6:
		print(f'Wrong number of hole punches, exiting...')
		exit(4)

	holePunches = sorted(holePunches, key = lambda hp: hp['dist'])
	
	i = 0
	for hp in holePunches :
		hp['order'] = i 
		#cv2.putText(img, str(i + 1), (hp['x'], hp['y']), cv2.FONT_HERSHEY_SIMPLEX, 20, (0, 0, 255), 5, cv2.LINE_AA, False)
		i+=1

	return holePunches

def correct_rotation (img, original, holePunches) :
	horizLines = [
		(3, 1),
		(6, 4),
		(5, 2)
	]
	vertsLines = [
		(1, 2),
		(1, 4), #double long left
		(1, 4), #
		(3, 5),
		(3, 6), #double long right
		(3, 6),  #
		(2, 4),
		(5, 6)
	]

	rotations = []

	for h in horizLines :
		line = draw_line(img, holePunches, h[0], h[1])
		angle = horiz_angle(line)
		print(angle)
		rotations.append(angle)

	for v in vertsLines :
		line = draw_line(img, holePunches, v[0], v[1])
		angle = verts_angle(line)
		print(angle)
		rotations.append(angle)

	correctionRotation = mean(rotations) - 180
	print(f'Mean rotation: {correctionRotation}')

	(cX, cY) = (width // 2, height // 2)
	M = cv2.getRotationMatrix2D((cX, cY), correctionRotation, 1.0)

	#create rotation of original
	return cv2.warpAffine(original, M, (width, height))

def create_blank (w, h, rgb_color = (255, 255, 255)) :
	blank = np.zeros([h, w, 3], dtype=np.uint8)
	color = tuple(reversed(rgb_color))
	blank[:] = color
	return blank

def get_mean_rect (holePunches) :
	left = 0
	right = 0
	top = 0
	bottom = 0
	for hp in holePunches :
		if hp['order'] == 0 :
			left += float(hp['x'])
			top += float(hp['y'])
		elif hp['order'] == 2 :
			right += float(hp['x'])
			top += float(hp['y'])
		elif hp['order'] == 3 :
			left += float(hp['x'])
			bottom += float(hp['y'])
		elif hp['order'] == 5 :
			right += float(hp['x'])
			bottom += float(hp['y'])
	w = round((right / 2.0) - (left / 2.0))
	h = round((bottom / 2.0) - (top / 2.0))
	return (w, h)


def center_within (larger, smaller) :
	w1 = larger[0]
	h1 = larger[1]
	w2 = smaller[0]
	h2 = smaller[1]
	x = ((w1 - w2) / 2)
	y = ((h1 - h2) / 2)
	return (int(x), int(y))

# If we consider (0,0) as top left corner of image called 
# im with left-to-right as x direction and top-to-bottom 
# as y direction. and we have (x1,y1) as the top-left vertex 
# and (x2,y2) as the bottom-right vertex of a rectangle 
# region within that image, then:
#
# roi = im[y1:y2, x1:x2]

def crop (img, xoffset, yoffset, w, h) :
	#crop_img = img[y:y+h, x:x+w].copy()
	return im[yoffset:yoffset+w, xoffset:xoffset+w].copy()

def normalize_image(blank, rotated, offset, tl) :
	rotatedHeight, rotatedWidth = rotated.shape[:2]
	normalHeight, width = blank.shape[:2]

	diffX = offset[0] - tl["x"]
	diffY = offset[1] - tl["y"]

	print(f'diffX  : {diffX}')
	print(f'diffY  : {diffY}')

	crop = rotated.copy()
	if diffX < 0 :
		crop = crop[0:rotatedHeight, abs(diffX):rotatedWidth]
		rotatedHeight, rotatedWidth = crop.shape[:2]
		print('Cropped X')
		print(f'Rotated: {rotatedWidth},{rotatedHeight}')
		diffX = 0

	if diffY < 0 :
		crop = crop[abs(diffY):rotatedHeight, 0:rotatedWidth]
		rotatedHeight, rotatedWidth = crop.shape[:2]
		print('Cropped Y')
		print(f'Rotated: {rotatedWidth},{rotatedHeight}')
		diffY = 0

	if rotatedWidth > width :
		crop = crop[0:rotatedHeight, 0:rotatedWidth-(rotatedWidth - width)]
		rotatedHeight, rotatedWidth = crop.shape[:2]
		print('Cropped X')
		print(f'Rotated: {rotatedWidth},{rotatedHeight}')

	if  rotatedHeight > normalHeight :
		crop = crop[0:rotatedHeight-(rotatedHeight - normalHeight), 0:width]
		rotatedHeight, rotatedWidth = crop.shape[:2]
		print('Cropped Y')
		print(f'Rotated: {rotatedWidth},{rotatedHeight}')

	print(f'diffX  : {diffX}')
	print(f'diffY  : {diffY}')

	print(f'Rotated: {rotatedWidth},{rotatedHeight}')
	print(f'Blank  : {width},{normalHeight}')

	cropHeight = normalHeight
	cropWidth = width 

	if normalHeight > rotatedHeight :
		cropHeight = rotatedHeight

	if width > rotatedWidth :
		cropWidth = rotatedWidth

	blank[diffY:cropHeight, diffX:cropWidth] = crop[0:cropHeight-diffY, 0:cropWidth - diffX]

	return blank

if len(sys.argv) < 2:
	print('Please provide path of scan to normalize')
	exit(1)

if len(sys.argv) < 3:
	print('Please provide path to output file')
	exit(2)

scanImage = sys.argv[-2]
normalImage = sys.argv[-1]
pageDim = (11, 8.5)
pageRatio = pageDim[1] / pageDim[0]

print(f'Normalizing {scanImage} as {normalImage}')

original = cv2.imread(scanImage)
img = original.copy()

height, width = img.shape[:2]
orientation = height > width
if not orientation :
	print(f'Scan is not in portrait mode, exiting...')
	exit(3)

normalHeight = round(float(width) / pageRatio)

holePunches = find_hole_punches(img)
rotated = correct_rotation(img, original, holePunches)
rotatedHeight, rotatedWidth = rotated.shape[:2]

holePunches = find_hole_punches(rotated)
blank = create_blank(width, normalHeight)

tl = None
for hp in holePunches :
	if tl is None :
		tl = hp
	print(f'{hp["order"] + 1} {hp["x"]},{hp["y"]}')

print(f'Normal dimensions: {width},{normalHeight}')

# the mean rectangle is the average width and height
# determined by the four corner hole punches
meanRect = get_mean_rect(holePunches)
print(f'Mean rectangle: {meanRect[0]},{meanRect[1]}')

# offset is the position within the new normal image
# the top left hole punch should be centered to
offset = center_within((width, normalHeight), meanRect)
print(f'Offset : {offset[0]},{offset[1]}')
print(f'Topleft: {tl["x"]},{tl["y"]}')
print(f'Rotated: {rotatedWidth},{rotatedHeight}')
print(f'Blank  : {width},{normalHeight}')

#cv2.rectangle(blank, offset, (offset[0]+meanRect[0], offset[1]+meanRect[1]), (255, 0, 0), thickness=20)

normal = normalize_image(blank, rotated, offset, tl)

print(f'Writing normalized image to {normalImage}')
cv2.imwrite(normalImage, normal)
#display(normal)