#!/user/bin/env python
# coding=utf-8

import uuid
from typing import Optional

import gradio as gr
import matplotlib

matplotlib.use('Agg')
import os
import sys
import yaml
from argparse import ArgumentParser
from tqdm import tqdm

import imageio
import numpy as np
from skimage.transform import resize
from skimage import img_as_ubyte
import torch
from sync_batchnorm import DataParallelWithCallback

from modules.generator import OcclusionAwareGenerator
from modules.keypoint_detector import KPDetector
from animate import normalize_kp
from scipy.spatial import ConvexHull

if sys.version_info[0] < 3:
    raise Exception("You must use Python 3 or higher. Recommended version is Python 3.7")


def load_checkpoints(config_path, checkpoint_path, cpu=True):
    with open(config_path) as f:
        config = yaml.load(f, Loader=yaml.FullLoader)

    generator = OcclusionAwareGenerator(**config['model_params']['generator_params'],
                                        **config['model_params']['common_params'])
    if not cpu:
        generator.cuda()

    kp_detector = KPDetector(**config['model_params']['kp_detector_params'],
                             **config['model_params']['common_params'])
    if not cpu:
        kp_detector.cuda()

    if cpu:
        checkpoint = torch.load(checkpoint_path, map_location=torch.device('cpu'))
    else:
        checkpoint = torch.load(checkpoint_path)

    generator.load_state_dict(checkpoint['generator'])
    kp_detector.load_state_dict(checkpoint['kp_detector'])

    if not cpu:
        generator = DataParallelWithCallback(generator)
        kp_detector = DataParallelWithCallback(kp_detector)

    generator.eval()
    kp_detector.eval()

    return generator, kp_detector


def make_animation(source_image, driving_video, generator, kp_detector, relative=True, adapt_movement_scale=True,
                   cpu=True):
    with torch.no_grad():
        predictions = []
        source = torch.tensor(source_image[np.newaxis].astype(np.float32)).permute(0, 3, 1, 2)
        if not cpu:
            source = source.cuda()
        driving = torch.tensor(np.array(driving_video)[np.newaxis].astype(np.float32)).permute(0, 4, 1, 2, 3)
        kp_source = kp_detector(source)
        kp_driving_initial = kp_detector(driving[:, :, 0])

        for frame_idx in tqdm(range(driving.shape[2])):
            driving_frame = driving[:, :, frame_idx]
            if not cpu:
                driving_frame = driving_frame.cuda()
            kp_driving = kp_detector(driving_frame)
            kp_norm = normalize_kp(kp_source=kp_source, kp_driving=kp_driving,
                                   kp_driving_initial=kp_driving_initial, use_relative_movement=relative,
                                   use_relative_jacobian=relative, adapt_movement_scale=adapt_movement_scale)
            out = generator(source, kp_source=kp_source, kp_driving=kp_norm)

            predictions.append(np.transpose(out['prediction'].data.cpu().numpy(), [0, 2, 3, 1])[0])
    return predictions


def find_best_frame(source, driving, cpu=False):
    import face_alignment

    def normalize_kp(kp):
        kp = kp - kp.mean(axis=0, keepdims=True)
        area = ConvexHull(kp[:, :2]).volume
        area = np.sqrt(area)
        kp[:, :2] = kp[:, :2] / area
        return kp

    fa = face_alignment.FaceAlignment(face_alignment.LandmarksType._2D, flip_input=True,
                                      device='cpu' if cpu else 'cuda')
    kp_source = fa.get_landmarks(255 * source)[0]
    kp_source = normalize_kp(kp_source)
    norm = float('inf')
    frame_num = 0
    for i, image in tqdm(enumerate(driving)):
        kp_driving = fa.get_landmarks(255 * image)[0]
        kp_driving = normalize_kp(kp_driving)
        new_norm = (np.abs(kp_source - kp_driving) ** 2).sum()
        if new_norm < norm:
            norm = new_norm
            frame_num = i
    return frame_num


def h_interface(input_image: np.ndarray):
    parser = ArgumentParser()
    opt = parser.parse_args()
    opt.config = "./config/vox-adv-256.yaml"
    opt.checkpoint = "./checkpoints/vox-adv-cpk.pth.tar"
    opt.source_image = input_image
    opt.driving_video = "./data/chuck.mp4"
    opt.result_video = "./data/result.mp4".format(uuid.uuid1().hex)
    opt.relative = True
    opt.adapt_scale = True
    opt.cpu = True
    opt.find_best_frame = False
    opt.best_frame = False

    source_image = opt.source_image
    reader = imageio.get_reader(opt.driving_video)
    fps = reader.get_meta_data()['fps']
    driving_video = []
    try:
        for im in reader:
            driving_video.append(im)
    except RuntimeError:
        pass
    reader.close()

    source_image = resize(source_image, (256, 256))[..., :3]
    driving_video = [resize(frame, (256, 256))[..., :3] for frame in driving_video]
    generator, kp_detector = load_checkpoints(config_path=opt.config, checkpoint_path=opt.checkpoint, cpu=opt.cpu)

    if opt.find_best_frame or opt.best_frame is not None:
        i = opt.best_frame if opt.best_frame is not None else find_best_frame(source_image, driving_video, cpu=opt.cpu)
        print("Best frame: " + str(i))
        driving_forward = driving_video[i:]
        driving_backward = driving_video[:(i + 1)][::-1]
        predictions_forward = make_animation(source_image, driving_forward, generator, kp_detector,
                                             relative=opt.relative, adapt_movement_scale=opt.adapt_scale, cpu=opt.cpu)
        predictions_backward = make_animation(source_image, driving_backward, generator, kp_detector,
                                              relative=opt.relative, adapt_movement_scale=opt.adapt_scale, cpu=opt.cpu)
        predictions = predictions_backward[::-1] + predictions_forward[1:]
    else:
        predictions = make_animation(source_image, driving_video, generator, kp_detector, relative=opt.relative,
                                     adapt_movement_scale=opt.adapt_scale, cpu=opt.cpu)
    imageio.mimsave(opt.result_video, [img_as_ubyte(frame) for frame in predictions], fps=fps)
    return opt.result_video


if __name__ == "__main__":
    demo = gr.Interface(
        fn=h_interface,
        inputs=gr.Image(type="numpy", label="Input Image"),
        outputs=gr.Video(label="Output Video")
    )

    demo.launch()
