import os
from functools import reduce
import cv2
import numpy as np
from PIL import Image, ImageFont, ImageDraw
import sys
sys.path.append(os.path.dirname(os.path.abspath(__file__)) + "/../")


def pil_resize(image_np, height, width):
    image_pil = Image.fromarray(cv2.cvtColor(image_np, cv2.COLOR_BGR2RGB))
    image_pil = image_pil.resize((int(width), int(height)), Image.BICUBIC)
    image_np = cv2.cvtColor(np.asarray(image_pil), cv2.COLOR_RGB2BGR)
    return image_np


def get_best_predict_size(image_np, times=8, min_size=128, max_size=400):
    sizes = []
    for i in range(int(min_size/times), 100):
        if i*times <= max_size:
            sizes.append(i*times)
    sizes.sort(key=lambda x: x, reverse=True)

    min_len = 10000
    best_height = sizes[0]
    for height in sizes:
        if abs(image_np.shape[0] - height) < min_len:
            min_len = abs(image_np.shape[0] - height)
            best_height = height

    min_len = 10000
    best_width = sizes[0]
    for width in sizes:
        if abs(image_np.shape[1] - width) < min_len:
            min_len = abs(image_np.shape[1] - width)
            best_width = width

    if best_height > best_width:
        best_width = best_height
    else:
        best_height = best_width

    return best_height, best_width


def letterbox_image(image, size):
    """resize image with unchanged aspect ratio using padding"""
    iw, ih = image.size
    w, h = size
    scale = min(w/iw, h/ih)
    nw = int(iw*scale)
    nh = int(ih*scale)

    image = image.resize((nw,nh), Image.BICUBIC)
    new_image = Image.new('RGB', size, (128,128,128))
    new_image.paste(image, ((w-nw)//2, (h-nh)//2))
    return new_image


def compose(*funcs):
    """Compose arbitrarily many functions, evaluated left to right.
    Reference: https://mathieularose.com/function-composition-in-python/
    """
    if funcs:
        return reduce(lambda f, g: lambda *a, **kw: g(f(*a, **kw)), funcs)
    else:
        raise ValueError('Composition of empty sequence not supported.')


def draw_boxes(image, out_boxes, out_classes, out_scores, class_names, colors):
    font = ImageFont.truetype(font=os.path.abspath(os.path.dirname(__file__))+'/font/FiraMono-Medium.otf',
                              size=np.floor(3e-2 * image.size[1] + 0.5).astype('int32'))
    thickness = (image.size[0] + image.size[1]) // 300

    box_list = []
    for i, c in reversed(list(enumerate(out_classes))):
        predicted_class = class_names[c]
        box = out_boxes[i]
        score = out_scores[i]

        label = '{} {:.2f}'.format(predicted_class, score)
        draw = ImageDraw.Draw(image)
        label_size = draw.textsize(label, font)

        top, left, bottom, right = box
        top = max(0, np.floor(top + 0.5).astype('int32'))
        left = max(0, np.floor(left + 0.5).astype('int32'))
        bottom = min(image.size[1], np.floor(bottom + 0.5).astype('int32'))
        right = min(image.size[0], np.floor(right + 0.5).astype('int32'))
        # print(label, (left, top), (right, bottom))
        box_list.append([(left, top), (right, bottom)])

        if top - label_size[1] >= 0:
            text_origin = np.array([left, top - label_size[1]])
        else:
            text_origin = np.array([left, top + 1])

        # My kingdom for a good redistributable image drawing library.
        for i in range(thickness):
            draw.rectangle(
                [left + i, top + i, right - i, bottom - i],
                outline=colors[c])
        draw.rectangle(
            [tuple(text_origin), tuple(text_origin + label_size)],
            fill=colors[c])
        draw.text(text_origin, label, fill=(0, 0, 0), font=font)
        del draw

    return image


def adjust_boxes(image, boxes, threshold=10):
    new_boxes = []
    for box in boxes:
        w, h = image.size
        top, left, bottom, right = box
        top = max(0, np.floor(top + 0.5).astype('int32'))
        left = max(0, np.floor(left + 0.5).astype('int32'))
        bottom = min(h, np.floor(bottom + 0.5).astype('int32'))
        right = min(w, np.floor(right + 0.5).astype('int32'))

        # 把框加大，有时候圈不全
        top = 0 if top - threshold < 0 else top - threshold
        bottom = h if bottom + threshold > h else bottom + threshold
        left = 0 if left - threshold < 0 else left - threshold
        right = w if right + threshold > w else right + threshold

        new_boxes.append([(left, top), (right, bottom)])
    return new_boxes