"""
Tests to ensure that the training loop works with a dict
"""
from pytorch_lightning import Trainer
from tests.base.model_template import EvalModelTemplate
import os


def test_training_step_scalar(tmpdir):
    """
    Tests that only training_step can be used
    """
    os.environ['PL_DEV_DEBUG'] = '1'

    model = EvalModelTemplate()
    model.validation_step = None
    model.test_step = None
    model.training_step = model.training_step_result_obj_dp
    model.training_step_end = None
    model.training_epoch_end = None
    model.validation_step = model.validation_step_result_obj_dp
    model.validation_step_end = None
    model.validation_epoch_end = None
    model.test_dataloader = None

    trainer = Trainer(
        default_root_dir=tmpdir,
        limit_train_batches=2,
        limit_val_batches=2,
        max_epochs=2,
        row_log_interval=1,
        weights_summary=None,
    )
    trainer.fit(model)

    # epoch 0
    assert trainer.dev_debugger.logged_metrics[0]['global_step'] == 0
    assert trainer.dev_debugger.logged_metrics[1]['global_step'] == 1
    assert trainer.dev_debugger.logged_metrics[2]['global_step'] == 1

    # epoch 1
    assert trainer.dev_debugger.logged_metrics[3]['global_step'] == 2
    assert trainer.dev_debugger.logged_metrics[4]['global_step'] == 3
    assert trainer.dev_debugger.logged_metrics[5]['global_step'] == 3