import glob
import math
import os
import subprocess
import time

import cv2
import numpy
import python_speech_features
import torch

from scipy import signal
from scipy.io import wavfile


# ==================== Get OFFSET ====================


def calc_pdist(feat1, feat2, vshift=10):
    win_size = vshift * 2 + 1

    feat2p = torch.nn.functional.pad(feat2, (0, 0, vshift, vshift))

    dists = []

    for i in range(0, len(feat1)):
        dists.append(
            torch.nn.functional.pairwise_distance(
                feat1[[i], :].repeat(win_size, 1), feat2p[i : i + win_size, :]
            )
        )

    return dists


# ==================== MAIN DEF ====================


class SyncNetInstance(torch.nn.Module):
    def __init__(
        self,
        net: torch.nn.Module,
        device: str = "cuda",
        dropout: float = 0,
        num_layers_in_fc_layers: int = 1024,
    ):
        super(SyncNetInstance, self).__init__()
        self.__S__ = net
        self.device = device

    def evaluate(self, opt):
        self.__S__.to(self.device)
        self.__S__.eval()

        # ========== ==========
        # Load video
        # ========== ==========

        images = []

        flist = glob.glob(os.path.join(opt.tmp_dir, "*.jpg"))
        flist.sort()

        for fname in flist:
            images.append(cv2.imread(fname))

        im = numpy.stack(images, axis=3)
        im = numpy.expand_dims(im, axis=0)
        im = numpy.transpose(im, (0, 3, 4, 1, 2))

        imtv = torch.autograd.Variable(torch.from_numpy(im.astype(float)).float())

        # ========== ==========
        # Load audio
        # ========== ==========

        sample_rate, audio = wavfile.read(os.path.join(opt.tmp_dir, "audio.wav"))
        mfcc = zip(*python_speech_features.mfcc(audio, sample_rate))
        mfcc = numpy.stack([numpy.array(i) for i in mfcc])

        cc = numpy.expand_dims(numpy.expand_dims(mfcc, axis=0), axis=0)
        cct = torch.autograd.Variable(torch.from_numpy(cc.astype(float)).float())

        # ========== ==========
        # Check audio and video input length
        # ========== ==========

        if (float(len(audio)) / 16000) != (float(len(images)) / 25):
            print(
                "WARNING: Audio (%.4fs) and video (%.4fs) lengths are different."
                % (float(len(audio)) / 16000, float(len(images)) / 25)
            )

        min_length = min(len(images), math.floor(len(audio) / 640))

        # ========== ==========
        # Generate video and audio feats
        # ========== ==========

        lastframe = min_length - 5
        im_feat = []
        cc_feat = []

        tS = time.time()
        for i in range(0, lastframe, opt.batch_size):
            im_batch = [
                imtv[:, :, vframe : vframe + 5, :, :]
                for vframe in range(i, min(lastframe, i + opt.batch_size))
            ]
            im_in = torch.cat(im_batch, 0).to(self.device)
            im_out = self.__S__.forward_lip(im_in)
            im_feat.append(im_out.data.cpu())

            cc_batch = [
                cct[:, :, :, vframe * 4 : vframe * 4 + 20]
                for vframe in range(i, min(lastframe, i + opt.batch_size))
            ]
            cc_in = torch.cat(cc_batch, 0).to(self.device)
            cc_out = self.__S__.forward_aud(cc_in)
            cc_feat.append(cc_out.data.cpu())

        im_feat = torch.cat(im_feat, 0)
        cc_feat = torch.cat(cc_feat, 0)

        # ========== ==========
        # Compute offset
        # ========== ==========

        print("Compute time %.3f sec." % (time.time() - tS))

        dists = calc_pdist(im_feat, cc_feat, vshift=opt.vshift)
        mdist = torch.mean(torch.stack(dists, 1), 1)

        minval, minidx = torch.min(mdist, 0)

        offset = opt.vshift - minidx
        conf = torch.median(mdist) - minval

        fdist = numpy.stack([dist[minidx].numpy() for dist in dists])
        # fdist   = numpy.pad(fdist, (3,3), 'constant', constant_values=15)
        fconf = torch.median(mdist).numpy() - fdist
        fconfm = signal.medfilt(fconf, kernel_size=9)

        numpy.set_printoptions(formatter={"float": "{: 0.3f}".format})
        print("Framewise conf: ")
        print(fconfm)
        print(
            "AV offset: \t%d \nSync-D score: \t%.3f\nSync-C score: \t%.3f"
            % (offset, minval, conf)
        )

        # dists_npy = numpy.array([dist.numpy() for dist in dists])
        # return offset.numpy(), conf.numpy(), minval.numpy()
        return int(offset), float(conf), float(minval)

    def extract_feature(self, opt, videofile):
        self.__S__.eval()
        # ========== ==========
        # Load video
        # ========== ==========
        cap = cv2.VideoCapture(videofile)

        frame_num = 1
        images = []
        while frame_num:
            frame_num += 1
            ret, image = cap.read()
            if ret == 0:
                break

            images.append(image)

        im = numpy.stack(images, axis=3)
        im = numpy.expand_dims(im, axis=0)
        im = numpy.transpose(im, (0, 3, 4, 1, 2))

        imtv = torch.autograd.Variable(torch.from_numpy(im.astype(float)).float())

        # ========== ==========
        # Generate video feats
        # ========== ==========

        lastframe = len(images) - 4
        im_feat = []

        tS = time.time()
        for i in range(0, lastframe, opt.batch_size):
            im_batch = [
                imtv[:, :, vframe : vframe + 5, :, :]
                for vframe in range(i, min(lastframe, i + opt.batch_size))
            ]
            im_in = torch.cat(im_batch, 0).to(self.device)
            im_out = self.__S__.forward_lipfeat(im_in)
            im_feat.append(im_out.data.cpu())

        im_feat = torch.cat(im_feat, 0)

        # ========== ==========
        # Compute offset
        # ========== ==========

        print("Compute time %.3f sec." % (time.time() - tS))

        return im_feat

    def loadParameters(self, path):
        loaded_state = torch.load(path, map_location=lambda storage, loc: storage)
        self_state = self.__S__.state_dict()
        for name, param in loaded_state.items():
            self_state[name].copy_(param)