from __future__ import print_function
import cv2 as cv
import numpy as np
import argparse
import random as rng

rng.seed(12345)


def calculate_parameters(contour, gray_image):
    area = cv.contourArea(contour)
    perimeter = cv.arcLength(contour, True)
    x, y, w, h = cv.boundingRect(contour)
    aspect_ratio = float(w) / h
    rect_area = w * h
    extent = float(area) / rect_area
    hull = cv.convexHull(contour)
    hull_area = cv.contourArea(hull)
    solidity = float(area) / hull_area
    equi_diameter = np.sqrt(4 * area / np.pi)
    if len(contour) >= 5:
        (x, y), (MA, ma), angle = cv.fitEllipse(contour)
    else:
        angle = 0
    mask = np.zeros_like(gray_image)
    cv.drawContours(mask, [contour], -1, 255, -1)
    mean_val = cv.mean(gray_image, mask=mask)[0]
    return {
        "Area": area,
        "Perimeter": perimeter,
        "Aspect Ratio": aspect_ratio,
        "Extent": extent,
        "Solidity": solidity,
        "Equivalent Diameter": equi_diameter,
        "Orientation": angle,
        "Mean Intensity": mean_val
    }


def thresh_callback(val):
    threshold = val
    canny_output = cv.Canny(src_gray, threshold, threshold * 2)
    contours, _ = cv.findContours(canny_output, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)

    drawing = np.zeros((canny_output.shape[0], canny_output.shape[1], 3), dtype=np.uint8)

    for i, contour in enumerate(contours):
        color = (rng.randint(0, 256), rng.randint(0, 256), rng.randint(0, 256))
        cv.drawContours(drawing, contours, i, color)

        # Compute and print parameters for each contour
        params = calculate_parameters(contour, src_gray)
        print(f"Contour #{i + 1}:")
        for param_name, param_value in params.items():
            print(f"  {param_name}: {param_value}")

    cv.imshow('Contours', drawing)


parser = argparse.ArgumentParser(description='Code for Creating Bounding boxes and circles for contours tutorial.')
parser.add_argument('--input', help='Path to input image.', default='water_coins.jpg')
args = parser.parse_args()

src = cv.imread(cv.samples.findFile(args.input))
if src is None:
    print('Could not open or find the image:', args.input)
    exit(0)

src_gray = cv.cvtColor(src, cv.COLOR_BGR2GRAY)
src_gray = cv.blur(src_gray, (3, 3))

source_window = 'Source'
cv.namedWindow(source_window)
cv.imshow(source_window, src)

max_thresh = 255
thresh = 100
cv.createTrackbar('Canny thresh:', source_window, thresh, max_thresh, thresh_callback)
thresh_callback(thresh)

cv.waitKey()