import os
from unittest.mock import patch

import pytest

from pytorch_lightning import Trainer
from pytorch_lightning.loggers import CometLogger
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from tests.base import EvalModelTemplate


def test_comet_logger_online():
    """Test comet online with mocks."""
    # Test api_key given
    with patch('pytorch_lightning.loggers.comet.CometExperiment') as comet:
        logger = CometLogger(
            api_key='key',
            workspace='dummy-test',
            project_name='general'
        )

        _ = logger.experiment

        comet.assert_called_once_with(
            api_key='key',
            workspace='dummy-test',
            project_name='general'
        )

    # Test both given
    with patch('pytorch_lightning.loggers.comet.CometExperiment') as comet:
        logger = CometLogger(
            save_dir='test',
            api_key='key',
            workspace='dummy-test',
            project_name='general'
        )

        _ = logger.experiment

        comet.assert_called_once_with(
            api_key='key',
            workspace='dummy-test',
            project_name='general'
        )

    # Test neither given
    with pytest.raises(MisconfigurationException):
        CometLogger(
            workspace='dummy-test',
            project_name='general'
        )

    # Test already exists
    with patch('pytorch_lightning.loggers.comet.CometExistingExperiment') as comet_existing:
        logger = CometLogger(
            experiment_key='test',
            experiment_name='experiment',
            api_key='key',
            workspace='dummy-test',
            project_name='general'
        )

        _ = logger.experiment

        comet_existing.assert_called_once_with(
            api_key='key',
            workspace='dummy-test',
            project_name='general',
            previous_experiment='test'
        )

        comet_existing().set_name.assert_called_once_with('experiment')

    with patch('pytorch_lightning.loggers.comet.API') as api:
        CometLogger(
            api_key='key',
            workspace='dummy-test',
            project_name='general',
            rest_api_key='rest'
        )

        api.assert_called_once_with('rest')


def test_comet_logger_dirs_creation(tmpdir, monkeypatch):
    """ Test that the logger creates the folders and files in the right place. """
    # prevent comet logger from trying to print at exit, since
    # pytest's stdout/stderr redirection breaks it
    import atexit
    monkeypatch.setattr(atexit, 'register', lambda _: None)

    logger = CometLogger(project_name='test', save_dir=tmpdir)
    assert not os.listdir(tmpdir)
    assert logger.mode == 'offline'
    assert logger.save_dir == tmpdir

    _ = logger.experiment
    version = logger.version
    assert set(os.listdir(tmpdir)) == {f'{logger.experiment.id}.zip'}

    model = EvalModelTemplate()
    trainer = Trainer(default_root_dir=tmpdir, logger=logger, max_epochs=1, limit_val_batches=3)
    trainer.fit(model)

    assert trainer.checkpoint_callback.dirpath == (tmpdir / 'test' / version / 'checkpoints')
    assert set(os.listdir(trainer.checkpoint_callback.dirpath)) == {'epoch=0.ckpt'}