def main(tempdir):
    monai.config.print_config()
    logging.basicConfig(stream=sys.stdout, level=logging.INFO)

    print(f"generating synthetic data to {tempdir} (this may take a while)")
    for i in range(5):
        im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1, channel_dim=-1)

        n = nib.Nifti1Image(im, np.eye(4))
        nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))

        n = nib.Nifti1Image(seg, np.eye(4))
        nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))

    images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
    segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
    val_files = [{"img": img, "seg": seg} for img, seg in zip(images, segs)]

    # define transforms for image and segmentation
    val_transforms = Compose(
        [
            LoadNiftid(keys=["img", "seg"]),
            AsChannelFirstd(keys=["img", "seg"], channel_dim=-1),
            ScaleIntensityd(keys="img"),
            ToTensord(keys=["img", "seg"]),
        ]
    )
    val_ds = monai.data.Dataset(data=val_files, transform=val_transforms)
    # sliding window inference need to input 1 image in every iteration
    val_loader = DataLoader(val_ds, batch_size=1, num_workers=4, collate_fn=list_data_collate)
    dice_metric = DiceMetric(include_background=True, reduction="mean")
    post_trans = Compose([Activations(sigmoid=True), AsDiscrete(threshold_values=True)])
    # try to use all the available GPUs
    devices = get_devices_spec(None)
    model = UNet(
        dimensions=3,
        in_channels=1,
        out_channels=1,
        channels=(16, 32, 64, 128, 256),
        strides=(2, 2, 2, 2),
        num_res_units=2,
    ).to(devices[0])

    model.load_state_dict(torch.load("best_metric_model_segmentation3d_dict.pth"))

    # if we have multiple GPUs, set data parallel to execute sliding window inference
    if len(devices) > 1:
        model = torch.nn.DataParallel(model, device_ids=devices)

    model.eval()
    with torch.no_grad():
        metric_sum = 0.0
        metric_count = 0
        saver = NiftiSaver(output_dir="./output")
        for val_data in val_loader:
            val_images, val_labels = val_data["img"].to(devices[0]), val_data["seg"].to(devices[0])
            # define sliding window size and batch size for windows inference
            roi_size = (96, 96, 96)
            sw_batch_size = 4
            val_outputs = sliding_window_inference(val_images, roi_size, sw_batch_size, model)
            val_outputs = post_trans(val_outputs)
            value, _ = dice_metric(y_pred=val_outputs, y=val_labels)
            metric_count += len(value)
            metric_sum += value.item() * len(value)
            saver.save_batch(val_outputs, val_data["img_meta_dict"])
        metric = metric_sum / metric_count
        print("evaluation metric:", metric)
def main():
    opt = Options().parse()
    # monai.config.print_config()
    logging.basicConfig(stream=sys.stdout, level=logging.INFO)

    if opt.gpu_ids != '-1':
        num_gpus = len(opt.gpu_ids.split(','))
    else:
        num_gpus = 0
    print('number of GPU:', num_gpus)

    # Data loader creation

    # train images
    train_images = sorted(
        glob(os.path.join(opt.images_folder, 'train', 'image*.nii')))
    train_segs = sorted(
        glob(os.path.join(opt.labels_folder, 'train', 'label*.nii')))

    train_images_for_dice = sorted(
        glob(os.path.join(opt.images_folder, 'train', 'image*.nii')))
    train_segs_for_dice = sorted(
        glob(os.path.join(opt.labels_folder, 'train', 'label*.nii')))

    # validation images
    val_images = sorted(
        glob(os.path.join(opt.images_folder, 'val', 'image*.nii')))
    val_segs = sorted(
        glob(os.path.join(opt.labels_folder, 'val', 'label*.nii')))

    # test images
    test_images = sorted(
        glob(os.path.join(opt.images_folder, 'test', 'image*.nii')))
    test_segs = sorted(
        glob(os.path.join(opt.labels_folder, 'test', 'label*.nii')))

    # augment the data list for training
    for i in range(int(opt.increase_factor_data)):

        train_images.extend(train_images)
        train_segs.extend(train_segs)

    print('Number of training patches per epoch:', len(train_images))
    print('Number of training images per epoch:', len(train_images_for_dice))
    print('Number of validation images per epoch:', len(val_images))
    print('Number of test images per epoch:', len(test_images))

    # Creation of data directories for data_loader

    train_dicts = [{
        'image': image_name,
        'label': label_name
    } for image_name, label_name in zip(train_images, train_segs)]

    train_dice_dicts = [{
        'image': image_name,
        'label': label_name
    }
                        for image_name, label_name in zip(
                            train_images_for_dice, train_segs_for_dice)]

    val_dicts = [{
        'image': image_name,
        'label': label_name
    } for image_name, label_name in zip(val_images, val_segs)]

    test_dicts = [{
        'image': image_name,
        'label': label_name
    } for image_name, label_name in zip(test_images, test_segs)]

    # Transforms list

    if opt.resolution is not None:
        train_transforms = [
            LoadNiftid(keys=['image', 'label']),
            AddChanneld(keys=['image', 'label']),
            NormalizeIntensityd(keys=['image']),
            ScaleIntensityd(keys=['image']),
            Spacingd(keys=['image', 'label'],
                     pixdim=opt.resolution,
                     mode=('bilinear', 'nearest')),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=1),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=0),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=2),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 36, np.pi / 36, np.pi * 2),
                        padding_mode="zeros"),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 36, np.pi / 2, np.pi / 36),
                        padding_mode="zeros"),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 2, np.pi / 36, np.pi / 36),
                        padding_mode="zeros"),
            Rand3DElasticd(keys=['image', 'label'],
                           mode=('bilinear', 'nearest'),
                           prob=0.1,
                           sigma_range=(5, 8),
                           magnitude_range=(100, 200),
                           scale_range=(0.15, 0.15, 0.15),
                           padding_mode="zeros"),
            RandAdjustContrastd(keys=['image'], gamma=(0.5, 2.5), prob=0.1),
            RandGaussianNoised(keys=['image'],
                               prob=0.1,
                               mean=np.random.uniform(0, 0.5),
                               std=np.random.uniform(0, 1)),
            RandShiftIntensityd(keys=['image'],
                                offsets=np.random.uniform(0, 0.3),
                                prob=0.1),
            RandSpatialCropd(keys=['image', 'label'],
                             roi_size=opt.patch_size,
                             random_size=False),
            ToTensord(keys=['image', 'label'])
        ]

        val_transforms = [
            LoadNiftid(keys=['image', 'label']),
            AddChanneld(keys=['image', 'label']),
            NormalizeIntensityd(keys=['image']),
            ScaleIntensityd(keys=['image']),
            Spacingd(keys=['image', 'label'],
                     pixdim=opt.resolution,
                     mode=('bilinear', 'nearest')),
            ToTensord(keys=['image', 'label'])
        ]
    else:
        train_transforms = [
            LoadNiftid(keys=['image', 'label']),
            AddChanneld(keys=['image', 'label']),
            NormalizeIntensityd(keys=['image']),
            ScaleIntensityd(keys=['image']),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=1),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=0),
            RandFlipd(keys=['image', 'label'], prob=0.1, spatial_axis=2),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 36, np.pi / 36, np.pi * 2),
                        padding_mode="zeros"),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 36, np.pi / 2, np.pi / 36),
                        padding_mode="zeros"),
            RandAffined(keys=['image', 'label'],
                        mode=('bilinear', 'nearest'),
                        prob=0.1,
                        rotate_range=(np.pi / 2, np.pi / 36, np.pi / 36),
                        padding_mode="zeros"),
            Rand3DElasticd(keys=['image', 'label'],
                           mode=('bilinear', 'nearest'),
                           prob=0.1,
                           sigma_range=(5, 8),
                           magnitude_range=(100, 200),
                           scale_range=(0.15, 0.15, 0.15),
                           padding_mode="zeros"),
            RandAdjustContrastd(keys=['image'], gamma=(0.5, 2.5), prob=0.1),
            RandGaussianNoised(keys=['image'],
                               prob=0.1,
                               mean=np.random.uniform(0, 0.5),
                               std=np.random.uniform(0, 1)),
            RandShiftIntensityd(keys=['image'],
                                offsets=np.random.uniform(0, 0.3),
                                prob=0.1),
            RandSpatialCropd(keys=['image', 'label'],
                             roi_size=opt.patch_size,
                             random_size=False),
            ToTensord(keys=['image', 'label'])
        ]

        val_transforms = [
            LoadNiftid(keys=['image', 'label']),
            AddChanneld(keys=['image', 'label']),
            NormalizeIntensityd(keys=['image']),
            ScaleIntensityd(keys=['image']),
            ToTensord(keys=['image', 'label'])
        ]

    train_transforms = Compose(train_transforms)
    val_transforms = Compose(val_transforms)

    # create a training data loader
    check_train = monai.data.Dataset(data=train_dicts,
                                     transform=train_transforms)
    train_loader = DataLoader(check_train,
                              batch_size=opt.batch_size,
                              shuffle=True,
                              num_workers=opt.workers,
                              pin_memory=torch.cuda.is_available())

    # create a training_dice data loader
    check_val = monai.data.Dataset(data=train_dice_dicts,
                                   transform=val_transforms)
    train_dice_loader = DataLoader(check_val,
                                   batch_size=1,
                                   num_workers=opt.workers,
                                   pin_memory=torch.cuda.is_available())

    # create a validation data loader
    check_val = monai.data.Dataset(data=val_dicts, transform=val_transforms)
    val_loader = DataLoader(check_val,
                            batch_size=1,
                            num_workers=opt.workers,
                            pin_memory=torch.cuda.is_available())

    # create a validation data loader
    check_val = monai.data.Dataset(data=test_dicts, transform=val_transforms)
    test_loader = DataLoader(check_val,
                             batch_size=1,
                             num_workers=opt.workers,
                             pin_memory=torch.cuda.is_available())

    # try to use all the available GPUs
    devices = get_devices_spec(None)

    # build the network
    net = build_net()
    net.cuda()

    if num_gpus > 1:
        net = torch.nn.DataParallel(net)

    if opt.preload is not None:
        net.load_state_dict(torch.load(opt.preload))

    dice_metric = DiceMetric(include_background=True,
                             to_onehot_y=False,
                             sigmoid=True,
                             reduction="mean")

    # loss_function = monai.losses.DiceLoss(sigmoid=True)
    loss_function = monai.losses.TverskyLoss(sigmoid=True, alpha=0.3, beta=0.7)

    optim = torch.optim.Adam(net.parameters(), lr=opt.lr)
    net_scheduler = get_scheduler(optim, opt)

    # start a typical PyTorch training
    val_interval = 1
    best_metric = -1
    best_metric_epoch = -1
    epoch_loss_values = list()
    metric_values = list()
    writer = SummaryWriter()
    for epoch in range(opt.epochs):
        print("-" * 10)
        print(f"epoch {epoch + 1}/{opt.epochs}")
        net.train()
        epoch_loss = 0
        step = 0
        for batch_data in train_loader:
            step += 1
            inputs, labels = batch_data["image"].cuda(
            ), batch_data["label"].cuda()
            optim.zero_grad()
            outputs = net(inputs)
            loss = loss_function(outputs, labels)
            loss.backward()
            optim.step()
            epoch_loss += loss.item()
            epoch_len = len(check_train) // train_loader.batch_size
            print(f"{step}/{epoch_len}, train_loss: {loss.item():.4f}")
            writer.add_scalar("train_loss", loss.item(),
                              epoch_len * epoch + step)
        epoch_loss /= step
        epoch_loss_values.append(epoch_loss)
        print(f"epoch {epoch + 1} average loss: {epoch_loss:.4f}")
        update_learning_rate(net_scheduler, optim)

        if (epoch + 1) % val_interval == 0:
            net.eval()
            with torch.no_grad():

                def plot_dice(images_loader):

                    metric_sum = 0.0
                    metric_count = 0
                    val_images = None
                    val_labels = None
                    val_outputs = None
                    for data in images_loader:
                        val_images, val_labels = data["image"].cuda(
                        ), data["label"].cuda()
                        roi_size = opt.patch_size
                        sw_batch_size = 4
                        val_outputs = sliding_window_inference(
                            val_images, roi_size, sw_batch_size, net)
                        value = dice_metric(y_pred=val_outputs, y=val_labels)
                        metric_count += len(value)
                        metric_sum += value.item() * len(value)
                    metric = metric_sum / metric_count
                    metric_values.append(metric)
                    return metric, val_images, val_labels, val_outputs

                metric, val_images, val_labels, val_outputs = plot_dice(
                    val_loader)

                # Save best model
                if metric > best_metric:
                    best_metric = metric
                    best_metric_epoch = epoch + 1
                    torch.save(net.state_dict(), "best_metric_model.pth")
                    print("saved new best metric model")

                metric_train, train_images, train_labels, train_outputs = plot_dice(
                    train_dice_loader)
                metric_test, test_images, test_labels, test_outputs = plot_dice(
                    test_loader)

                # Logger bar
                print(
                    "current epoch: {} Training dice: {:.4f} Validation dice: {:.4f} Testing dice: {:.4f} Best Validation dice: {:.4f} at epoch {}"
                    .format(epoch + 1, metric_train, metric, metric_test,
                            best_metric, best_metric_epoch))

                writer.add_scalar("Mean_epoch_loss", epoch_loss, epoch + 1)
                writer.add_scalar("Testing_dice", metric_test, epoch + 1)
                writer.add_scalar("Training_dice", metric_train, epoch + 1)
                writer.add_scalar("Validation_dice", metric, epoch + 1)
                # plot the last model output as GIF image in TensorBoard with the corresponding image and label
                val_outputs = (val_outputs.sigmoid() >= 0.5).float()
                plot_2d_or_3d_image(val_images,
                                    epoch + 1,
                                    writer,
                                    index=0,
                                    tag="validation image")
                plot_2d_or_3d_image(val_labels,
                                    epoch + 1,
                                    writer,
                                    index=0,
                                    tag="validation label")
                plot_2d_or_3d_image(val_outputs,
                                    epoch + 1,
                                    writer,
                                    index=0,
                                    tag="validation inference")

    print(
        f"train completed, best_metric: {best_metric:.4f} at epoch: {best_metric_epoch}"
    )
    writer.close()