# coding: utf-8
__author__ = 'Roman Solovyev (ZFTurbo): https://github.com/ZFTurbo/'
__version__ = '1.0.3'

import random
import argparse
import time
import copy
from tqdm import tqdm
import sys
import os
import glob
import torch
import soundfile as sf
import numpy as np
import auraloss
import torch.nn as nn
from torch.optim import Adam, AdamW, SGD
from torch.utils.data import DataLoader
from torch.cuda.amp.grad_scaler import GradScaler
from torch.optim.lr_scheduler import ReduceLROnPlateau
import torch.nn.functional as F

from dataset import MSSDataset
from utils import demix_track, demix_track_demucs, sdr, get_model_from_config

import warnings

warnings.filterwarnings("ignore")


def masked_loss(y_, y, q, coarse=True):
    # shape = [num_sources, batch_size, num_channels, chunk_size]
    loss = torch.nn.MSELoss(reduction='none')(y_, y).transpose(0, 1)
    if coarse:
        loss = torch.mean(loss, dim=(-1, -2))
    loss = loss.reshape(loss.shape[0], -1)
    L = loss.detach()
    quantile = torch.quantile(L, q, interpolation='linear', dim=1, keepdim=True)
    mask = L < quantile
    return (loss * mask).mean()


def manual_seed(seed):
    random.seed(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    torch.cuda.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)  # if multi-GPU
    torch.backends.cudnn.deterministic = True
    os.environ["PYTHONHASHSEED"] = str(seed)


def load_not_compatible_weights(model, weights, verbose=False):
    new_model = model.state_dict()
    old_model = torch.load(weights)
    if 'state' in old_model:
        # Fix for htdemucs weights loading
        old_model = old_model['state']

    for el in new_model:
        if el in old_model:
            if verbose:
                print('Match found for {}!'.format(el))
            if new_model[el].shape == old_model[el].shape:
                if verbose:
                    print('Action: Just copy weights!')
                new_model[el] = old_model[el]
            else:
                if len(new_model[el].shape) != len(old_model[el].shape):
                    if verbose:
                        print('Action: Different dimension! Too lazy to write the code... Skip it')
                else:
                    if verbose:
                        print('Shape is different: {} != {}'.format(tuple(new_model[el].shape), tuple(old_model[el].shape)))
                    ln = len(new_model[el].shape)
                    max_shape = []
                    slices_old = []
                    slices_new = []
                    for i in range(ln):
                        max_shape.append(max(new_model[el].shape[i], old_model[el].shape[i]))
                        slices_old.append(slice(0, old_model[el].shape[i]))
                        slices_new.append(slice(0, new_model[el].shape[i]))
                    # print(max_shape)
                    # print(slices_old, slices_new)
                    slices_old = tuple(slices_old)
                    slices_new = tuple(slices_new)
                    max_matrix = np.zeros(max_shape, dtype=np.float32)
                    for i in range(ln):
                        max_matrix[slices_old] = old_model[el].cpu().numpy()
                    max_matrix = torch.from_numpy(max_matrix)
                    new_model[el] = max_matrix[slices_new]
        else:
            if verbose:
                print('Match not found for {}!'.format(el))
    model.load_state_dict(
        new_model
    )

def valid(model, args, config, device, verbose=False):
    # For multiGPU extract single model
    if len(args.device_ids) > 1:
        model = model.module

    model.eval()
    all_mixtures_path = []
    for valid_path in args.valid_path:
        part = sorted(glob.glob(valid_path + '/*/mixture.wav'))
        if len(part) == 0:
            print('No validation data found in: {}'.format(valid_path))
        all_mixtures_path += part
    if verbose:
        print('Total mixtures: {}'.format(len(all_mixtures_path)))

    instruments = config.training.instruments
    if config.training.target_instrument is not None:
        instruments = [config.training.target_instrument]

    all_sdr = dict()
    for instr in config.training.instruments:
        all_sdr[instr] = []

    if not verbose:
        all_mixtures_path = tqdm(all_mixtures_path)

    pbar_dict = {}
    for path in all_mixtures_path:
        mix, sr = sf.read(path)
        folder = os.path.dirname(path)
        if verbose:
            print('Song: {}'.format(os.path.basename(folder)))
        mixture = torch.tensor(mix.T, dtype=torch.float32)
        if args.model_type == 'htdemucs':
            res = demix_track_demucs(config, model, mixture, device)
        else:
            res = demix_track(config, model, mixture, device)
        for instr in instruments:
            if instr != 'other' or config.training.other_fix is False:
                track, sr1 = sf.read(folder + '/{}.wav'.format(instr))
            else:
                # other is actually instrumental
                track, sr1 = sf.read(folder + '/{}.wav'.format('vocals'))
                track = mix - track
            # sf.write("{}.wav".format(instr), res[instr].T, sr, subtype='FLOAT')
            references = np.expand_dims(track, axis=0)
            estimates = np.expand_dims(res[instr].T, axis=0)
            sdr_val = sdr(references, estimates)[0]
            if verbose:
                print(instr, res[instr].shape, sdr_val)
            all_sdr[instr].append(sdr_val)
            pbar_dict['sdr_{}'.format(instr)] = sdr_val
        if not verbose:
            all_mixtures_path.set_postfix(pbar_dict)

    sdr_avg = 0.0
    for instr in instruments:
        sdr_val = np.array(all_sdr[instr]).mean()
        print("Instr SDR {}: {:.4f}".format(instr, sdr_val))
        sdr_avg += sdr_val
    sdr_avg /= len(instruments)
    if len(instruments) > 1:
        print('SDR Avg: {:.4f}'.format(sdr_avg))
    return sdr_avg


def proc_list_of_files(
    mixture_paths,
    model,
    args,
    config,
    device,
    verbose=False,
):
    instruments = config.training.instruments
    if config.training.target_instrument is not None:
        instruments = [config.training.target_instrument]

    all_sdr = dict()
    for instr in config.training.instruments:
        all_sdr[instr] = []

    for path in mixture_paths:
        mix, sr = sf.read(path)
        folder = os.path.dirname(path)
        folder_name = os.path.abspath(folder)
        if verbose:
            print('Song: {}'.format(folder_name))
        mixture = torch.tensor(mix.T, dtype=torch.float32)
        if args.model_type == 'htdemucs':
            res = demix_track_demucs(config, model, mixture, device)
        else:
            res = demix_track(config, model, mixture, device)
        if 1:
            pbar_dict = {}
            for instr in instruments:
                if instr != 'other' or config.training.other_fix is False:
                    try:
                        track, sr1 = sf.read(folder + '/{}.wav'.format(instr))
                    except Exception as e:
                        # print('No data for stem: {}. Skip!'.format(instr))
                        continue
                else:
                    # other is actually instrumental
                    track, sr1 = sf.read(folder + '/{}.wav'.format('vocals'))
                    track = mix - track

                references = np.expand_dims(track, axis=0)
                estimates = np.expand_dims(res[instr].T, axis=0)
                sdr_val = sdr(references, estimates)[0]
                if verbose:
                    print(instr, res[instr].shape, sdr_val)
                all_sdr[instr].append(sdr_val)
                pbar_dict['sdr_{}'.format(instr)] = sdr_val

            try:
                mixture_paths.set_postfix(pbar_dict)
            except Exception as e:
                pass

    return all_sdr


def valid_mp(proc_id, queue, all_mixtures_path, model, args, config, device, return_dict):
    m1 = model
    # m1 = copy.deepcopy(m1)
    m1 = m1.eval().to(device)
    if proc_id == 0:
        progress_bar = tqdm(total=len(all_mixtures_path))
    all_sdr = dict()
    for instr in config.training.instruments:
        all_sdr[instr] = []
    while True:
        current_step, path = queue.get()
        if path is None:  # check for sentinel value
            break
        sdr_single = proc_list_of_files([path], m1, args, config, device, False)
        pbar_dict = {}
        for instr in config.training.instruments:
            all_sdr[instr] += sdr_single[instr]
            if len(sdr_single[instr]) > 0:
                pbar_dict['sdr_{}'.format(instr)] = "{:.4f}".format(sdr_single[instr][0])
        if proc_id == 0:
            progress_bar.update(current_step - progress_bar.n)
            progress_bar.set_postfix(pbar_dict)
        # print(f"Inference on process {proc_id}", all_sdr)
    return_dict[proc_id] = all_sdr
    return


def valid_multi_gpu(model, args, config, verbose=False):
    device_ids = args.device_ids
    model = model.to('cpu')

    # For multiGPU extract single model
    if len(device_ids) > 1:
        model = model.module

    all_mixtures_path = []
    for valid_path in args.valid_path:
        part = sorted(glob.glob(valid_path + '/*/mixture.wav'))
        if len(part) == 0:
            print('No validation data found in: {}'.format(valid_path))
        all_mixtures_path += part

    model = model.to('cpu')
    torch.cuda.empty_cache()
    queue = torch.multiprocessing.Queue()
    processes = []
    return_dict = torch.multiprocessing.Manager().dict()
    for i, device in enumerate(device_ids):
        if torch.cuda.is_available():
            device = 'cuda:{}'.format(device)
        else:
            device = 'cpu'
        p = torch.multiprocessing.Process(target=valid_mp, args=(i, queue, all_mixtures_path, model, args, config, device, return_dict))
        p.start()
        processes.append(p)
    for i, path in enumerate(all_mixtures_path):
        queue.put((i, path))
    for _ in range(len(device_ids)):
        queue.put((None, None))  # sentinel value to signal subprocesses to exit
    for p in processes:
        p.join()  # wait for all subprocesses to finish

    all_sdr = dict()
    for instr in config.training.instruments:
        all_sdr[instr] = []
        for i in range(len(device_ids)):
            all_sdr[instr] += return_dict[i][instr]

    instruments = config.training.instruments
    if config.training.target_instrument is not None:
        instruments = [config.training.target_instrument]

    sdr_avg = 0.0
    for instr in instruments:
        sdr_val = np.array(all_sdr[instr]).mean()
        print("Instr SDR {}: {:.4f}".format(instr, sdr_val))
        sdr_avg += sdr_val
    sdr_avg /= len(instruments)
    if len(instruments) > 1:
        print('SDR Avg: {:.4f}'.format(sdr_avg))
    return sdr_avg


def train_model(args):
    parser = argparse.ArgumentParser()
    parser.add_argument("--model_type", type=str, default='mdx23c', help="One of mdx23c, htdemucs, segm_models, mel_band_roformer, bs_roformer, swin_upernet, bandit")
    parser.add_argument("--config_path", type=str, help="path to config file")
    parser.add_argument("--start_check_point", type=str, default='', help="Initial checkpoint to start training")
    parser.add_argument("--results_path", type=str, help="path to folder where results will be stored (weights, metadata)")
    parser.add_argument("--data_path", nargs="+", type=str, help="Dataset data paths. You can provide several folders.")
    parser.add_argument("--dataset_type", type=int, default=1, help="Dataset type. Must be one of: 1, 2, 3 or 4. Details here: https://github.com/ZFTurbo/Music-Source-Separation-Training/blob/main/docs/dataset_types.md")
    parser.add_argument("--valid_path", nargs="+", type=str, help="validation data paths. You can provide several folders.")
    parser.add_argument("--num_workers", type=int, default=0, help="dataloader num_workers")
    parser.add_argument("--pin_memory", type=bool, default=False, help="dataloader pin_memory")
    parser.add_argument("--seed", type=int, default=0, help="random seed")
    parser.add_argument("--device_ids", nargs='+', type=int, default=[0], help='list of gpu ids')
    parser.add_argument("--use_multistft_loss", action='store_true', help="Use MultiSTFT Loss (from auraloss package)")
    parser.add_argument("--use_mse_loss", action='store_true', help="Use default MSE loss")
    parser.add_argument("--use_l1_loss", action='store_true', help="Use L1 loss")
    if args is None:
        args = parser.parse_args()
    else:
        args = parser.parse_args(args)

    manual_seed(args.seed + int(time.time()))
    torch.backends.cudnn.benchmark = True
    torch.backends.cudnn.deterministic = False # Fix possible slow down with dilation convolutions
    torch.multiprocessing.set_start_method('spawn')

    model, config = get_model_from_config(args.model_type, args.config_path)
    print("Instruments: {}".format(config.training.instruments))

    if not os.path.isdir(args.results_path):
        os.mkdir(args.results_path)

    use_amp = True
    try:
        use_amp = config.training.use_amp
    except:
        pass

    device_ids = args.device_ids
    batch_size = config.training.batch_size * len(device_ids)

    trainset = MSSDataset(
        config,
        args.data_path,
        batch_size=batch_size,
        metadata_path=os.path.join(args.results_path, 'metadata_{}.pkl'.format(args.dataset_type)),
        dataset_type=args.dataset_type,
    )

    train_loader = DataLoader(
        trainset,
        batch_size=batch_size,
        shuffle=True,
        num_workers=args.num_workers,
        pin_memory=args.pin_memory
    )

    if args.start_check_point != '':
        print('Start from checkpoint: {}'.format(args.start_check_point))
        if 1:
            load_not_compatible_weights(model, args.start_check_point, verbose=False)
        else:
            model.load_state_dict(
                torch.load(args.start_check_point)
            )

    if torch.cuda.is_available():
        if len(device_ids) <= 1:
            print('Use single GPU: {}'.format(device_ids))
            device = torch.device(f'cuda:{device_ids[0]}')
            model = model.to(device)
        else:
            print('Use multi GPU: {}'.format(device_ids))
            device = torch.device(f'cuda:{device_ids[0]}')
            model = nn.DataParallel(model, device_ids=device_ids).to(device)
    else:
        device = 'cpu'
        print('CUDA is not avilable. Run training on CPU. It will be very slow...')
        model = model.to(device)

    if 0:
        valid_multi_gpu(model, args, config, verbose=True)

    if config.training.optimizer == 'adam':
        optimizer = Adam(model.parameters(), lr=config.training.lr)
    elif config.training.optimizer == 'adamw':
        optimizer = AdamW(model.parameters(), lr=config.training.lr)
    elif config.training.optimizer == 'sgd':
        print('Use SGD optimizer')
        optimizer = SGD(model.parameters(), lr=config.training.lr, momentum=0.999)
    else:
        print('Unknown optimizer: {}'.format(config.training.optimizer))
        exit()

    gradient_accumulation_steps = 1
    try:
        gradient_accumulation_steps = int(config.training.gradient_accumulation_steps)
    except:
        pass

    print("Patience: {} Reduce factor: {} Batch size: {} Grad accum steps: {} Effective batch size: {}".format(
        config.training.patience,
        config.training.reduce_factor,
        batch_size,
        gradient_accumulation_steps,
        batch_size * gradient_accumulation_steps,
    ))
    # Reduce LR if no SDR improvements for several epochs
    scheduler = ReduceLROnPlateau(optimizer, 'max', patience=config.training.patience, factor=config.training.reduce_factor)

    if args.use_multistft_loss:
        try:
            loss_options = dict(config.loss_multistft)
        except:
            loss_options = dict()
        print('Loss options: {}'.format(loss_options))
        loss_multistft = auraloss.freq.MultiResolutionSTFTLoss(
            **loss_options
        )

    scaler = GradScaler()
    print('Train for: {}'.format(config.training.num_epochs))
    best_sdr = -100
    for epoch in range(config.training.num_epochs):
        model.train().to(device)
        print('Train epoch: {} Learning rate: {}'.format(epoch, optimizer.param_groups[0]['lr']))
        loss_val = 0.
        total = 0

        # total_loss = None
        pbar = tqdm(train_loader)
        for i, (batch, mixes) in enumerate(pbar):
            y = batch.to(device)
            x = mixes.to(device)  # mixture

            with torch.cuda.amp.autocast(enabled=use_amp):
                if args.model_type in ['mel_band_roformer', 'bs_roformer']:
                    # loss is computed in forward pass
                    loss = model(x, y)
                    if type(device_ids) != int:
                        # If it's multiple GPUs sum partial loss
                        loss = loss.mean()
                else:
                    y_ = model(x)
                    if args.use_multistft_loss:
                        y1_ = torch.reshape(y_, (y_.shape[0], y_.shape[1] * y_.shape[2], y_.shape[3]))
                        y1 = torch.reshape(y, (y.shape[0], y.shape[1] * y.shape[2], y.shape[3]))
                        loss = loss_multistft(y1_, y1)
                        # We can use many losses at the same time
                        if args.use_mse_loss:
                            loss += 1000 * nn.MSELoss()(y1_, y1)
                        if args.use_l1_loss:
                            loss += 1000 * F.l1_loss(y1_, y1)
                    elif args.use_mse_loss:
                        loss = nn.MSELoss()(y_, y)
                    elif args.use_l1_loss:
                        loss = F.l1_loss(y_, y)
                    else:
                        loss = masked_loss(
                            y_,
                            y,
                            q=config.training.q,
                            coarse=config.training.coarse_loss_clip
                        )

            loss /= gradient_accumulation_steps
            scaler.scale(loss).backward()
            if config.training.grad_clip:
                nn.utils.clip_grad_norm_(model.parameters(), config.training.grad_clip)

            if ((i + 1) % gradient_accumulation_steps == 0) or (i == len(train_loader) - 1):
                scaler.step(optimizer)
                scaler.update()
                optimizer.zero_grad(set_to_none=True)

            li = loss.item() * gradient_accumulation_steps
            loss_val += li
            total += 1
            pbar.set_postfix({'loss': 100 * li, 'avg_loss': 100 * loss_val / (i + 1)})
            loss.detach()

        print('Training loss: {:.6f}'.format(loss_val / total))

        # Save last
        store_path = args.results_path + '/last_{}.ckpt'.format(args.model_type)
        state_dict = model.state_dict() if len(device_ids) <= 1 else model.module.state_dict()
        torch.save(
            state_dict,
            store_path
        )

        # if you have problem with multiproc validation change 0 to 1
        if 0:
            sdr_avg = valid(model, args, config, device, verbose=False)
        else:
            sdr_avg = valid_multi_gpu(model, args, config, verbose=False)
        if sdr_avg > best_sdr:
            store_path = args.results_path + '/model_{}_ep_{}_sdr_{:.4f}.ckpt'.format(args.model_type, epoch, sdr_avg)
            print('Store weights: {}'.format(store_path))
            state_dict = model.state_dict() if len(device_ids) <= 1 else model.module.state_dict()
            torch.save(
                state_dict,
                store_path
            )
            best_sdr = sdr_avg
        scheduler.step(sdr_avg)


if __name__ == "__main__":
    train_model(None)