from itertools import compress
from itertools import starmap
from operator import __and__

import cv2
import numpy as np
from pdf2image import pdf2image

from cv_analysis.utils.display import show_mpl
from cv_analysis.utils.draw import draw_rectangles
from cv_analysis.utils.post_processing import remove_overlapping, remove_included, has_no_parent
from cv_analysis.utils.visual_logging import vizlogger


def is_likely_segment(rect, min_area=100):
    return cv2.contourArea(rect, False) > min_area


def find_segments(image):
    contours, hierarchies = cv2.findContours(image, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    mask1 = map(is_likely_segment, contours)
    mask2 = map(has_no_parent, hierarchies[0])
    mask = starmap(__and__, zip(mask1, mask2))
    contours = compress(contours, mask)

    rectangles = (cv2.boundingRect(c) for c in contours)

    return rectangles


def parse_layout(image: np.array):

    image = image.copy()
    image_ = image.copy()

    if len(image_.shape) > 2:
        image_ = cv2.cvtColor(image_, cv2.COLOR_BGR2GRAY)
    #vizlogger.debug(image_, "layout01_start.png")

    image_ = cv2.GaussianBlur(image_, (7, 7), 0)
    #vizlogger.debug(image_, "layout02_blur.png")
    thresh = cv2.threshold(image_, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]
    vizlogger.debug(image_, "layout03_theshold.png")

    kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (5, 5))
    #vizlogger.debug(kernel, "layout04_kernel.png")
    dilate = cv2.dilate(thresh, kernel, iterations=4)
    #vizlogger.debug(dilate, "layout05_dilate.png")

    rects = list(find_segments(dilate))

    # -> Run meta detection on the previous detections TODO: refactor
    for rect in rects:
        x, y, w, h = rect
        cv2.rectangle(image, (x, y), (x + w, y + h), (0, 0, 0), -1)
        cv2.rectangle(image, (x, y), (x + w, y + h), (255, 255, 255), 7)
    #vizlogger.debug(image, "layout06_rectangles.png")

    _, image = cv2.threshold(image, 254, 255, cv2.THRESH_BINARY)
    #vizlogger.debug(image, "layout07_threshold.png")
    image = ~image
    #vizlogger.debug(image, "layout08_inverse.png")

    if len(image.shape) > 2:
        image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    #vizlogger.debug(image, "layout09_convertcolor.png")

    rects = find_segments(image)
    # <- End of meta detection

    rects = remove_included(rects)
    rects = remove_overlapping(rects)

    return list(rects)


def annotate_layout_in_pdf(pdf_path, page_index=1, return_rects=False, show=False):

    page = pdf2image.convert_from_path(pdf_path, first_page=page_index + 1, last_page=page_index + 1)[0]
    page = np.array(page)

    rects = parse_layout(page)

    if return_rects:
        return rects, page
    elif show:
        page = draw_rectangles(page, rects)
        vizlogger.debug(page, "layout10_output.png")
        show_mpl(page)
    else:
        page = draw_rectangles(page, rects)
        return page


"""
def find_layout_boxes(image: np.array):

    if len(image.shape) > 2:
        image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    image = cv2.GaussianBlur(image, (5, 5), 1)
    image = cv2.threshold(image, 253, 255, cv2.THRESH_BINARY)[1]
    img_bin = ~image

    line_min_width = 10
    kernel_h = np.ones((10, line_min_width), np.uint8)
    kernel_v = np.ones((line_min_width, 10), np.uint8)

    img_bin_h = cv2.morphologyEx(img_bin, cv2.MORPH_OPEN, kernel_h)
    img_bin_v = cv2.morphologyEx(img_bin, cv2.MORPH_OPEN, kernel_v)

    img_bin_final = img_bin_h | img_bin_v

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

    for c in contours:
        peri = cv2.arcLength(c, True)
        approx = cv2.approxPolyDP(c, 0.04 * peri, True)
        yield cv2.boundingRect(approx)


def annotate_layout_boxes(image, rects):
    for rect in rects:
        (x, y, w, h) = rect
        cv2.rectangle(image, (x, y), (x + w, y + h), (0, 255, 0), 2)

    return image


def annotate_layout_in_pdf(pdf_path, page_index=1):

    page = pdf2image.convert_from_path(pdf_path, first_page=page_index + 1, last_page=page_index + 1)[0]
    page = np.array(page)

    layout_boxes = find_layout_boxes(page)
    page = annotate_layout_boxes(page, layout_boxes)

    fig, ax = plt.subplots(1, 1)
    fig.set_size_inches(20, 20)
    ax.imshow(page)
    plt.show()

"""