import cv2
import numpy as np

def distanceBtwPoints(p0, p1):
    return np.sqrt((p0[0] - p1[0])**2 + (p0[1] - p1[1])**2)

def findNearestPointIndex(pt, Points):
    mindistance = 1e9

    for i in range(len(Points)):
        print "Points i", Points[i]
        print "pt", pt
        distance = distanceBtwPoints(pt, Points[i])
        print 'distance', distance

        if distance < mindistance :
            mindistance =  distance
            nearestpointindex = i



    return  nearestpointindex

if __name__ == '__main__':
    img = cv2.imread("bridgeTestSource.png")
    src = cv2.imread("bridgeTestSource.png")

    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    gray = np.asarray(gray < 127, dtype=np.uint8) # need to cast back to uint8


    contours, hierarchy = cv2.findContours(gray, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)

    cv2.drawContours(img, contours,-1, (0,0,255), 2)


    for i in range(len(contours)):
        print "Contour ", i , "points", contours[i]
        print
        print " - Contour ", i, "area :", cv2.contourArea(contours[i])
        print
        for j in range(contours[i].shape[0]):
            print "contour x y", contours[i][j].squeeze()
        print "the contour" , i, "distance between ", contours[i][0].squeeze(),contours[i][1].squeeze(), "is " , distanceBtwPoints(contours[i][0].squeeze(), contours[i][1].squeeze())


    cnt = contours[0]

    for i in range(len(contours)):
        if len(cnt) < len(contours[i]):
            cnt = contours[i]

    for i in range(len(contours)):

        if not np.array_equal(cnt, contours[i]) and len(contours[i]) > 4:
            for j in range(len(contours[i])):
                pt0 = contours[i][j]

                cnt_nearIdx = cnt[findNearestPointIndex(pt0.squeeze(), cnt.squeeze())].squeeze()

                print "pt0", pt0
                print "cnt_nearIdx", cnt_nearIdx
                lcnt_nearIdx = cnt_nearIdx.tolist()
                lpt0 = (pt0.squeeze()).tolist()
                print "lpt0", lpt0

                tcnt_nearIdx = tuple(lcnt_nearIdx)
                tpt0 = tuple(lpt0)

                print "tpt0", tpt0
                print "tcnt_near", tcnt_nearIdx

                cv2.line(img,tpt0, tcnt_nearIdx,(0,0,0),1,8)


    cv2.imwrite('nimg.jpg', img)

    gray_src = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
    gray_src = np.asarray(gray_src < 127, dtype=np.uint8) # need to cast back to uint8


    contours1, hierarchy = cv2.findContours(gray_src, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    cv2.drawContours(src, contours1,-1, (0,0,0), 0)

    m_xor= np.ones(src.shape[:2], dtype="uint8") * 255

    print type(cnt)
    print cnt
    ncnt = cnt.astype(np.int32)
    print type(ncnt)

    cv2.polylines(m_xor, [ncnt], 1, (0,0,0))


    m_xor = 255 - (src or m_xor)

    cv2.imwrite('result.jpg', m_xor)