import math
import cv2
import numpy as np
from PIL import Image, ImageDraw, ImageFont


def crop_image(img, position):
    def distance(x1,y1,x2,y2):
        return math.sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2))    
    position = position.tolist()
    for i in range(4):
        for j in range(i+1, 4):
            if(position[i][0] > position[j][0]):
                tmp = position[j]
                position[j] = position[i]
                position[i] = tmp
    if position[0][1] > position[1][1]:
        tmp = position[0]
        position[0] = position[1]
        position[1] = tmp

    if position[2][1] > position[3][1]:
        tmp = position[2]
        position[2] = position[3]
        position[3] = tmp

    x1, y1 = position[0][0], position[0][1]
    x2, y2 = position[2][0], position[2][1]
    x3, y3 = position[3][0], position[3][1]
    x4, y4 = position[1][0], position[1][1]

    corners = np.zeros((4,2), np.float32)
    corners[0] = [x1, y1]
    corners[1] = [x2, y2]
    corners[2] = [x4, y4]
    corners[3] = [x3, y3]

    img_width = distance((x1+x4)/2, (y1+y4)/2, (x2+x3)/2, (y2+y3)/2)
    img_height = distance((x1+x2)/2, (y1+y2)/2, (x4+x3)/2, (y4+y3)/2)

    corners_trans = np.zeros((4,2), np.float32)
    corners_trans[0] = [0, 0]
    corners_trans[1] = [img_width - 1, 0]
    corners_trans[2] = [0, img_height - 1]
    corners_trans[3] = [img_width - 1, img_height - 1]

    transform = cv2.getPerspectiveTransform(corners, corners_trans)
    dst = cv2.warpPerspective(img, transform, (int(img_width), int(img_height)))
    return dst


def calculate_size(box):
    return (box[2]-box[0]) * (box[3]-box[1])


def calculate_iou(box1, box2):
    xA = max(box1[0], box2[0])
    yA = max(box1[1], box2[1])
    xB = min(box1[2], box2[2])
    yB = min(box1[3], box2[3])
    
    interArea = max(0, xB - xA) * max(0, yB - yA)
    box1Area = (box1[2] - box1[0]) * (box1[3] - box1[1])
    box2Area = (box2[2] - box2[0]) * (box2[3] - box2[1])
    unionArea = box1Area + box2Area - interArea
    iou = interArea / unionArea
    
    return iou


def crop(image, box, i, text_data=None):
    image = Image.open(image)

    if text_data:
        draw = ImageDraw.Draw(image)
        draw.rectangle(((text_data[0], text_data[1]), (text_data[2], text_data[3])), outline="red", width=5)
        # font_size = int((text_data[3] - text_data[1])*0.75)
        # font = ImageFont.truetype("arial.ttf", font_size)
        # draw.text((text_data[0]+5, text_data[1]+5), str(i), font=font, fill="red")

    cropped_image = image.crop(box)
    cropped_image.save(f"./temp/{i}.jpg")
    

def in_box(box, target):
    if (box[0] > target[0]) and (box[1] > target[1]) and (box[2] < target[2]) and (box[3] < target[3]):
        return True
    else:
        return False