#
# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import numpy as np

import PIL.Image as Image
import PIL.ImageDraw as ImageDraw
import PIL.ImageFont as ImageFont

COLORS = ['GoldenRod', 'MediumTurquoise', 'GreenYellow', 'SteelBlue', 'DarkSeaGreen', 'SeaShell', 'LightGrey',
          'IndianRed', 'DarkKhaki', 'LawnGreen', 'WhiteSmoke', 'Peru', 'LightCoral', 'FireBrick', 'OldLace',
          'LightBlue', 'SlateGray', 'OliveDrab', 'NavajoWhite', 'PaleVioletRed', 'SpringGreen', 'AliceBlue', 'Violet',
          'DeepSkyBlue', 'Red', 'MediumVioletRed', 'PaleTurquoise', 'Tomato', 'Azure', 'Yellow', 'Cornsilk',
          'Aquamarine', 'CadetBlue', 'CornflowerBlue', 'DodgerBlue', 'Olive', 'Orchid', 'LemonChiffon', 'Sienna',
          'OrangeRed', 'Orange', 'DarkSalmon', 'Magenta', 'Wheat', 'Lime', 'GhostWhite', 'SlateBlue', 'Aqua',
          'MediumAquaMarine', 'LightSlateGrey', 'MediumSeaGreen', 'SandyBrown', 'YellowGreen', 'Plum', 'FloralWhite',
          'LightPink', 'Thistle', 'DarkViolet', 'Pink', 'Crimson', 'Chocolate', 'DarkGrey', 'Ivory', 'PaleGreen',
          'DarkGoldenRod', 'LavenderBlush', 'SlateGrey', 'DeepPink', 'Gold', 'Cyan', 'LightSteelBlue', 'MediumPurple',
          'ForestGreen', 'DarkOrange', 'Tan', 'Salmon', 'PaleGoldenRod', 'LightGreen', 'LightSlateGray', 'HoneyDew',
          'Fuchsia', 'LightSeaGreen', 'DarkOrchid', 'Green', 'Chartreuse', 'LimeGreen', 'AntiqueWhite', 'Beige',
          'Gainsboro', 'Bisque', 'SaddleBrown', 'Silver', 'Lavender', 'Teal', 'LightCyan', 'PapayaWhip', 'Purple',
          'Coral', 'BurlyWood', 'LightGray', 'Snow', 'MistyRose', 'PowderBlue', 'DarkCyan', 'White', 'Turquoise',
          'MediumSlateBlue', 'PeachPuff', 'Moccasin', 'LightSalmon', 'SkyBlue', 'Khaki', 'MediumSpringGreen',
          'BlueViolet', 'MintCream', 'Linen', 'SeaGreen', 'HotPink', 'LightYellow', 'BlanchedAlmond', 'RoyalBlue',
          'RosyBrown', 'MediumOrchid', 'DarkTurquoise', 'LightGoldenRodYellow', 'LightSkyBlue']


def visualize_detections(image_path, output_path, detections, labels=[]):
    image = Image.open(image_path).convert(mode='RGB')
    draw = ImageDraw.Draw(image)
    line_width = 2
    font = ImageFont.load_default()
    for d in detections:
        color = COLORS[d['class'] % len(COLORS)]
        draw.line([(d['xmin'], d['ymin']), (d['xmin'], d['ymax']), (d['xmax'], d['ymax']), (d['xmax'], d['ymin']),
                   (d['xmin'], d['ymin'])], width=line_width, fill=color)
        label = "Class {}".format(d['class'])
        if d['class'] < len(labels):
            label = "{}".format(labels[d['class']])
        score = d['score']
        text = "{}: {}%".format(label, int(100 * score))
        if score < 0:
            text = label
        text_width, text_height = font.getsize(text)
        text_bottom = max(text_height, d['ymin'])
        text_left = d['xmin']
        margin = np.ceil(0.05 * text_height)
        draw.rectangle([(text_left, text_bottom - text_height - 2 * margin), (text_left + text_width, text_bottom)],
                       fill=color)
        draw.text((text_left + margin, text_bottom - text_height - margin), text, fill='black', font=font)
    if output_path is None:
        return image
    image.save(output_path)


def concat_visualizations(images, names, colors, output_path):
    def draw_text(draw, font, text, width, bar_height, offset, color):
        text_width, text_height = font.getsize(text)
        draw.rectangle([(offset, 0), (offset + width, bar_height)], fill=color)
        draw.text((offset + (width - text_width) / 2, text_height - text_height / 2), text, fill='black', font=font)

    bar_height = 18
    width = 0
    height = 0
    for im in images:
        width += im.width
        height = max(height, im.height)

    concat = Image.new('RGB', (width, height + bar_height))
    draw = ImageDraw.Draw(concat)
    font = ImageFont.load_default()

    offset = 0
    for i, im in enumerate(images):
        concat.paste(im, (offset, bar_height))
        draw_text(draw, font, names[i], im.width, bar_height, offset, colors[i])
        offset += im.width

    if output_path is None:
        return concat
    concat.save(output_path)