"""k-NN example using the Iris dataset."""

import prototorch as pt
import pytorch_lightning as pl
import torch

if __name__ == "__main__":
    # Dataset
    from sklearn.datasets import load_iris
    x_train, y_train = load_iris(return_X_y=True)
    x_train = x_train[:, [0, 2]]
    train_ds = pt.datasets.NumpyDataset(x_train, y_train)

    # Dataloaders
    train_loader = torch.utils.data.DataLoader(train_ds,
                                               num_workers=0,
                                               batch_size=150)

    # Hyperparameters
    hparams = dict(k=20)

    # Initialize the model
    model = pt.models.KNN(hparams, data=train_ds)

    # Callbacks
    vis = pt.models.VisGLVQ2D(data=(x_train, y_train))

    # Setup trainer
    trainer = pl.Trainer(max_epochs=1, callbacks=[vis])

    # Training loop
    # This is only for visualization. k-NN has no training phase.
    trainer.fit(model, train_loader)

    # Recall
    y_pred = model.predict(torch.tensor(x_train))
    print(y_pred)
