"""
(*)~---------------------------------------------------------------------------
Pupil - eye tracking platform
Copyright (C) 2012-2019 Pupil Labs

Distributed under the terms of the GNU
Lesser General Public License (LGPL v3.0).
See COPYING and COPYING.LESSER for license details.
---------------------------------------------------------------------------~(*)
"""

import struct

import numpy as np

fmt = "<5s 9d 8d 9d"


def pack(scene_sn, camera_matrix, dist_coefs, rotation_matrix):
    bytes_object = struct.pack(
        fmt,
        scene_sn.encode("utf-8"),
        *np.asarray(camera_matrix).ravel(),
        *np.asarray(dist_coefs).ravel(),
        *np.asarray(rotation_matrix).ravel()
    )
    return bytes_object


def unpack(bytes_object):
    data = struct.unpack(fmt, bytes_object)

    scene_sn = data[0].decode("utf-8")
    camera_matrix = np.array(data[1:10]).reshape(3, 3)
    dist_coefs = np.array(data[10:18]).reshape(1, 8)
    rotation_matrix = np.array(data[18:27]).reshape(3, 3)

    return scene_sn, camera_matrix, dist_coefs, rotation_matrix


if __name__ == "__main__":
    _scene_sn = "abcde"
    _camera_matrix = [
        [768.6506227400141, 0.0, 544.4086390822918],
        [0.0, 767.3984920290931, 542.8625702918421],
        [0.0, 0.0, 1.0],
    ]
    _dist_coefs = [
        [
            -0.12274814768315563,
            0.09836418807524534,
            0.0013970017965074415,
            -0.0002234252202650275,
            0.022460546276536732,
            0.20394056772660388,
            0.008570320041593258,
            0.07025679279405483,
        ]
    ]
    _rotation_matrix = [
        [-0.34290609741413736, -0.9252517728941283, -0.16224846721149222],
        [-0.3344758020769028, 0.28166226772991476, -0.8993288079241397],
        [0.8778048451570649, -0.2541171456110631, -0.4060580378779209],
    ]

    _bytes_object = pack(_scene_sn, _camera_matrix, _dist_coefs, _rotation_matrix)
    print(_bytes_object)

    print(unpack(_bytes_object))

    print(struct.calcsize(fmt))