"""
File: face_utils.py
Author: Elena Ryumina and Dmitry Ryumin
Description: This module contains utility functions related to facial landmarks and image processing.
License: MIT License
"""

import numpy as np
import math
import cv2


def norm_coordinates(normalized_x, normalized_y, image_width, image_height):
    x_px = min(math.floor(normalized_x * image_width), image_width - 1)
    y_px = min(math.floor(normalized_y * image_height), image_height - 1)
    return x_px, y_px


def get_box(fl, w, h):
    idx_to_coors = {}
    for idx, landmark in enumerate(fl.landmark):
        landmark_px = norm_coordinates(landmark.x, landmark.y, w, h)
        if landmark_px:
            idx_to_coors[idx] = landmark_px

    x_min = np.min(np.asarray(list(idx_to_coors.values()))[:, 0])
    y_min = np.min(np.asarray(list(idx_to_coors.values()))[:, 1])
    endX = np.max(np.asarray(list(idx_to_coors.values()))[:, 0])
    endY = np.max(np.asarray(list(idx_to_coors.values()))[:, 1])

    (startX, startY) = (max(0, x_min), max(0, y_min))
    (endX, endY) = (min(w - 1, endX), min(h - 1, endY))

    return startX, startY, endX, endY

def display_info(img, text, margin=1.0, box_scale=1.0):
    img_copy = img.copy()
    img_h, img_w, _ = img_copy.shape
    line_width = int(min(img_h, img_w) * 0.001)
    thickness = max(int(line_width / 3), 1)

    font_face = cv2.FONT_HERSHEY_SIMPLEX
    font_color = (0, 0, 0)
    font_scale = thickness / 1.5

    t_w, t_h = cv2.getTextSize(text, font_face, font_scale, None)[0]

    margin_n = int(t_h * margin)
    sub_img = img_copy[0 + margin_n: 0 + margin_n + t_h + int(2 * t_h * box_scale),
              img_w - t_w - margin_n - int(2 * t_h * box_scale): img_w - margin_n]

    white_rect = np.ones(sub_img.shape, dtype=np.uint8) * 255

    img_copy[0 + margin_n: 0 + margin_n + t_h + int(2 * t_h * box_scale),
    img_w - t_w - margin_n - int(2 * t_h * box_scale):img_w - margin_n] = cv2.addWeighted(sub_img, 0.5, white_rect, .5, 1.0)

    cv2.putText(img=img_copy,
                text=text,
                org=(img_w - t_w - margin_n - int(2 * t_h * box_scale) // 2,
                     0 + margin_n + t_h + int(2 * t_h * box_scale) // 2),
                fontFace=font_face,
                fontScale=font_scale,
                color=font_color,
                thickness=thickness,
                lineType=cv2.LINE_AA,
                bottomLeftOrigin=False)

    return img_copy