# -*-coding:utf-8-*-


import cv2
import numpy as np

object_pts = np.float32([[6.825897, 6.760612, 4.402142],
                         [1.330353, 7.122144, 6.903745],
                         [-1.330353, 7.122144, 6.903745],
                         [-6.825897, 6.760612, 4.402142],
                         [5.311432, 5.485328, 3.987654],
                         [1.789930, 5.393625, 4.413414],
                         [-1.789930, 5.393625, 4.413414],
                         [-5.311432, 5.485328, 3.987654],
                         [2.005628, 1.409845, 6.165652],
                         [-2.005628, 1.409845, 6.165652]])
reprojectsrc = np.float32([[10.0, 10.0, 10.0],
                           [10.0, 10.0, -10.0],
                           [10.0, -10.0, -10.0],
                           [10.0, -10.0, 10.0],
                           [-10.0, 10.0, 10.0],
                           [-10.0, 10.0, -10.0],
                           [-10.0, -10.0, -10.0],
                           [-10.0, -10.0, 10.0]])

line_pairs = [[0, 1], [1, 2], [2, 3], [3, 0],
              [4, 5], [5, 6], [6, 7], [7, 4],
              [0, 4], [1, 5], [2, 6], [3, 7]]


def get_head_pose(shape, img):
    h, w, _ = img.shape
    K = [w, 0.0, w // 2,
         0.0, w, h // 2,
         0.0, 0.0, 1.0]
    D = [0, 0, 0.0, 0.0, 0]
    cam_matrix = np.array(K).reshape(3, 3).astype(np.float32)
    dist_coeffs = np.array(D).reshape(5, 1).astype(np.float32)
    image_pts = np.float32([shape[17], shape[21], shape[22], shape[26], shape[36],
                            shape[39], shape[42], shape[45], shape[31], shape[35]])
    _, rotation_vec, translation_vec = cv2.solvePnP(object_pts, image_pts, cam_matrix, dist_coeffs)
    reprojectdst, _ = cv2.projectPoints(reprojectsrc, rotation_vec, translation_vec, cam_matrix, dist_coeffs)
    reprojectdst = tuple(map(tuple, reprojectdst.reshape(8, 2)))
    rotation_mat, _ = cv2.Rodrigues(rotation_vec)
    pose_mat = cv2.hconcat((rotation_mat, translation_vec))
    _, _, _, _, _, _, euler_angle = cv2.decomposeProjectionMatrix(pose_mat)
    return reprojectdst, euler_angle
