import os
import shutil

from PIL import Image, ImageFilter, ImageDraw, ImageFont
import numpy
import imutils
import cv2
import dumper
import random as rng
from pathlib import Path

from pdfminer.psparser import LIT

from .utils import cv2_rect, ensure_dir, set_file_perms, WORKDIR

# https://www.pyimagesearch.com/2014/10/20/finding-shapes-images-using-python-opencv/


def find_shapes(image_path):
    """Find shapes in the image, returning bounding boxes around each.
    Writes debug images next to the input image.
    """
    path = Path(image_path)

    print('finding shapes in {}'.format(image_path))

    img = Image.open(image_path, 'r')
    if img.mode == 'RGBA':
        alpha_layer = img.convert('RGBA').split()[-1]
    elif img.mode == 'L':
        alpha_layer = img
    else:
        print('unhandled image mode: {}'.format(img.mode))
        return None

    alpha_layer = alpha_layer.filter(ImageFilter.GaussianBlur(5))

    threshold = 5
    alpha_layer = alpha_layer.point(lambda p: p > threshold and 255)
    threshold = numpy.array(alpha_layer)

    # alternate method
    # blurred = cv2.GaussianBlur(gray, (5, 5), 0)
    # thresh = cv2.threshold(blurred, 60, 255, cv2.THRESH_BINARY)[1]

    thresh_path = str(path.with_suffix('.thresh.png'))
    cv2.imwrite(thresh_path, threshold)
    os.chmod(thresh_path, 0o664)
    shutil.chown(thresh_path, group='procat')

    contours = cv2.findContours(threshold, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    contours = imutils.grab_contours(contours)

    bboxes = []
    for c in contours:
        # bounding rect
        x, y, w, h = cv2.boundingRect(c)
        # essentially center of mass
        # NOT center of the bbox!
        # M = cv2.moments(c)
        # if M["m00"] == 0: M["m00"] = 0.00001
        # cX = int(M["m10"] / M["m00"])
        # cY = int(M["m01"] / M["m00"])
        bboxes.append(cv2_rect(x, y, w, h))

    # draw contours
    contour_image = numpy.zeros((threshold.shape[0], threshold.shape[1], 3), dtype=numpy.uint8)
    for i in range(len(contours)):
        color = (rng.randint(0,512), rng.randint(0,512), rng.randint(0,512))
        cv2.drawContours(contour_image, contours, i, color)
        rect = bboxes[i]
        cv2.rectangle(contour_image, (rect.left, rect.top), (rect.right, rect.bottom), color, 1)
        # cv2.circle(contour_image, (cX, cY), 2, color, -1)
        # cv2.putText(contour_image, "center", (cX - 20, cY - 15),
        #             cv2.FONT_HERSHEY_SIMPLEX, 0.5, color, 1)

    contour_path = str(path.with_suffix('.contour.png'))
    cv2.imwrite(contour_path, contour_image)
    os.chmod(contour_path, 0o664)
    shutil.chown(contour_path, group='procat')

    return img.width, img.height, bboxes


def write_debug_image(workdir, page_num, prods, scribbles):
    """Draw an image with boxes for products, images, and shapes."""
    ensure_dir(workdir)
    path = os.path.join(workdir, f"debug-page{page_num:03d}.png")

    pagew = int(11*72)
    pageh = int(8.5*72)

    img = Image.new('RGBA', (pagew, pageh), 'white')
    draw = ImageDraw.Draw(img, 'RGBA')
    fnt = ImageFont.truetype('/usr/share/fonts/truetype/lato/Lato-Regular.ttf', 10)

    for prod in filter(lambda p: p['page'] == page_num, prods):
        rect = prod['rect']
        fill_color = "hsv(120, 22%, 100%)" if 'matched' in prod else None
        outline_color = "hsv(120, 50%, 100%)"
        draw.rectangle((rect.p1(pageh), rect.p2(pageh)),
                       fill=fill_color, outline=outline_color, width=2)
        bl = rect.p1(pageh)
        draw.text((bl[0] + 3, bl[1] + 3), prod['material'],
                  font=fnt, fill="hsv(120, 22%, 50%)")

    for scribble in filter(lambda s: s['page'] == page_num, scribbles):
        rect = scribble['rect']
        draw.rectangle((rect.p1(pageh), rect.p2(pageh)), outline="hsv(210, 22%, 100%)", width=2)
        for box in scribble['bboxes']:
            draw.rectangle((box.p1(pageh), box.p2(pageh)), outline="hsv(0, 22%, 100%)", width=2)

    img.save(path)
    set_file_perms(path)


def write_inklist(obj, mediabox, path):
    """Draw an image of the inklist."""
    pagew = mediabox[2] - mediabox[0]
    pageh = mediabox[3] - mediabox[1]

    img = Image.new('RGBA', (pagew, pageh), (0, 0, 0, 0))
    draw = ImageDraw.Draw(img, 'RGBA')

    for segment in obj['InkList']:
        draw.line(segment, 'black', 3)

    # account for the difference in coordinate systems
    # between pdf and images.
    img = img.transpose(Image.FLIP_TOP_BOTTOM)

    img.save(path)
    set_file_perms(path)


def write_square_or_circle(obj, mediabox, path):
    """Draw an image of the inklist."""
    pagew = mediabox[2] - mediabox[0]
    pageh = mediabox[3] - mediabox[1]

    img = Image.new('RGBA', (pagew, pageh), (0, 0, 0, 0))
    draw = ImageDraw.Draw(img, 'RGBA')

    if obj["Subtype"] == LIT('Square'):
        draw.rectangle(obj['Rect'], fill=None, outline='black', width=3)
    else:
        draw.ellipse(*obj['Rect'], fill=None, outline='black', width=3)

    # account for the difference in coordinate systems
    # between pdf and images.
    img = img.transpose(Image.FLIP_TOP_BOTTOM)

    img.save(path)
    set_file_perms(path)