# -*- coding: UTF-8 -*-
import numpy as np

def find_minx(mat,val = 1):
    mat2 = mat.reshape((-1,1), order='F')
    (n,m) = mat.shape
    n2 = mat2.shape[0]
    for (el,idx) in zip(np.nditer(mat2),range(0,n2)):
        if el == val:
            return idx / n

    return None

def find_miny(mat,val = 1):
    mat2 = mat.reshape((1,-1))
    (n,m) = mat.shape
    n2 = mat2.shape[1]
    for (el,idx) in zip(np.nditer(mat2),range(0,n2)):
        if el == val:
            return idx / m

    return None

def find_maxx(mat,val = 1):
    mat2 = np.rot90(np.rot90(mat)).reshape((-1,1), order='F')
    (n,m) = mat.shape
    n2 = mat2.shape[0]
    for (el,idx) in zip(np.nditer(mat2),range(0,n2)):
        if el == val:
            return m - 1 - idx / n
    return None

def find_maxy(mat,val = 1):
    mat_rotated = np.rot90(np.rot90(mat))
    mat2 = mat_rotated.reshape((1,-1))
    (n,m) = mat.shape
    n2 = mat2.shape[1]
    for (el,idx) in zip(np.nditer(mat2),range(0,n2)):
        if el == val:
            return n - 1 - idx / m

    return None

def calc_image_crop(img, val = 255):
    minx = find_minx(img,val)
    maxx = find_maxx(img,val)
    miny = find_miny(img,val)
    maxy = find_maxy(img,val)
    return (minx,maxx,miny,maxy)