from typing import List

import torch
import os
import numpy as np
import cv2
import face_alignment
import subprocess

from helpers import *


def get_position(size, padding=0.25):
    x = [0.000213256, 0.0752622, 0.18113, 0.29077, 0.393397, 0.586856, 0.689483, 0.799124,
         0.904991, 0.98004, 0.490127, 0.490127, 0.490127, 0.490127, 0.36688, 0.426036,
         0.490127, 0.554217, 0.613373, 0.121737, 0.187122, 0.265825, 0.334606, 0.260918,
         0.182743, 0.645647, 0.714428, 0.793132, 0.858516, 0.79751, 0.719335, 0.254149,
         0.340985, 0.428858, 0.490127, 0.551395, 0.639268, 0.726104, 0.642159, 0.556721,
         0.490127, 0.423532, 0.338094, 0.290379, 0.428096, 0.490127, 0.552157, 0.689874,
         0.553364, 0.490127, 0.42689]

    y = [0.106454, 0.038915, 0.0187482, 0.0344891, 0.0773906, 0.0773906, 0.0344891,
         0.0187482, 0.038915, 0.106454, 0.203352, 0.307009, 0.409805, 0.515625, 0.587326,
         0.609345, 0.628106, 0.609345, 0.587326, 0.216423, 0.178758, 0.179852, 0.231733,
         0.245099, 0.244077, 0.231733, 0.179852, 0.178758, 0.216423, 0.244077, 0.245099,
         0.780233, 0.745405, 0.727388, 0.742578, 0.727388, 0.745405, 0.780233, 0.864805,
         0.902192, 0.909281, 0.902192, 0.864805, 0.784792, 0.778746, 0.785343, 0.778746,
         0.784792, 0.824182, 0.831803, 0.824182]

    x, y = np.array(x), np.array(y)

    x = (x + padding) / (2 * padding + 1)
    y = (y + padding) / (2 * padding + 1)
    x = x * size
    y = y * size
    return np.array(list(zip(x, y)))


def cal_area(anno):
    return (anno[:, 0].max() - anno[:, 0].min()) * (anno[:, 1].max() - anno[:, 1].min())


def output_video(p, txt, dst):
    files = os.listdir(p)
    files = sorted(files, key=lambda x: int(os.path.splitext(x)[0]))

    font = cv2.FONT_HERSHEY_SIMPLEX

    for file, line in zip(files, txt):
        img = cv2.imread(os.path.join(p, file))
        h, w, _ = img.shape
        img = cv2.putText(img, line, (w // 8, 11 * h // 12), font, 1.2, (0, 0, 0), 3, cv2.LINE_AA)
        img = cv2.putText(img, line, (w // 8, 11 * h // 12), font, 1.2, (255, 255, 255), 0, cv2.LINE_AA)
        h = h // 2
        w = w // 2
        img = cv2.resize(img, (w, h))
        cv2.imwrite(os.path.join(p, file), img)

    cmd = "ffmpeg -y -i {}/%d.jpg -r 25 \'{}\'".format(p, dst)
    os.system(cmd)


def transformation_from_points(points1, points2):
    points1 = points1.astype(np.float64)
    points2 = points2.astype(np.float64)

    c1 = np.mean(points1, axis=0)
    c2 = np.mean(points2, axis=0)
    points1 -= c1
    points2 -= c2
    s1 = np.std(points1)
    s2 = np.std(points2)
    points1 /= s1
    points2 /= s2

    U, S, Vt = np.linalg.svd(points1.T * points2)
    R = (U * Vt).T
    return np.vstack([
        np.hstack(((s2 / s1) * R,
        c2.T - (s2 / s1) * R * c1.T)),
        np.matrix([0., 0., 1.])
    ])


def load_video(path: str) -> List[np.ndarray]:
    """
    adapted original loading code using this tutorial about openCV
    https://learnopencv.com/read-write-and-display-a-video-using-opencv-cpp-python/
    """
    cap = cv2.VideoCapture(path)
    frames = []

    while cap.isOpened():
        ret, frame = cap.read()

        if ret is True:
            frames.append(frame)
        else:
            break

    cap.release()
    return frames


def extract_frames(
    video_filepath, recycle_landmarks=False,
    use_gpu=False
):
    device = 'cuda' if use_gpu else 'cpu'

    fa = face_alignment.FaceAlignment(
        face_alignment.LandmarksType.TWO_D,
        flip_input=False, device=device
    )

    array = load_video(video_filepath)
    array = list(filter(lambda im: not im is None, array))
    # array = [cv2.resize(im, (100, 50), interpolation=cv2.INTER_LANCZOS4)
    # for im in array]

    points = [fa.get_landmarks(I) for I in array]
    front256 = get_position(256)
    prev_landmarks = None
    frames = []

    for point, scene in zip(points, array):
        if point is not None:
            prev_landmarks = point
        elif recycle_landmarks and (prev_landmarks is not None):
            point = prev_landmarks
        else:
            frames.append(None)
            continue

        shape = np.array(point[0])
        shape = shape[17:]
        M = transformation_from_points(
            np.matrix(shape), np.matrix(front256)
        )

        img = cv2.warpAffine(scene, M[:2], (256, 256))
        (x, y) = front256[-20:].mean(0).astype(np.int32)
        w = 160 // 2
        img = img[y - w // 2:y + w // 2, x - w:x + w, ...]
        img = cv2.resize(img, (128, 64))
        frames.append(img)

    return frames


def export_frames(
    video_filepath, export_images_dir,
    recycle_landmarks=False, use_gpu=False,
    **kwargs
):
    frames = extract_frames(
        video_filepath, recycle_landmarks=recycle_landmarks,
        use_gpu=use_gpu
    )

    extraction_incomplete = False
    for k, image in enumerate(frames):
        if image is None:
            extraction_incomplete = True
            continue

        export_filepath = os.path.join(export_images_dir, f'{k}.jpg')
        cv2.imwrite(export_filepath, image)

    return extraction_incomplete