# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os

import pytest
import torch

from pytorch_lightning.callbacks import EarlyStopping, ModelCheckpoint
from pytorch_lightning.utilities.upgrade_checkpoint import upgrade_checkpoint


@pytest.mark.parametrize(
    "old_checkpoint, new_checkpoint",
    [
        (
            {
                "epoch": 1,
                "global_step": 23,
                "checkpoint_callback_best": 0.34
            },
            {
                "epoch": 1,
                "global_step": 23,
                "callbacks": {
                    ModelCheckpoint: {
                        "best_model_score": 0.34
                    }
                }
            },
        ),
        (
            {
                "epoch": 1,
                "global_step": 23,
                "checkpoint_callback_best_model_score": 0.99
            },
            {
                "epoch": 1,
                "global_step": 23,
                "callbacks": {
                    ModelCheckpoint: {
                        "best_model_score": 0.99
                    }
                }
            },
        ),
        (
            {
                "epoch": 1,
                "global_step": 23,
                "checkpoint_callback_best_model_path": 'path'
            },
            {
                "epoch": 1,
                "global_step": 23,
                "callbacks": {
                    ModelCheckpoint: {
                        "best_model_path": 'path'
                    }
                }
            },
        ),
        (
            {
                "epoch": 1,
                "global_step": 23,
                "early_stop_callback_wait": 2,
                "early_stop_callback_patience": 4
            },
            {
                "epoch": 1,
                "global_step": 23,
                "callbacks": {
                    EarlyStopping: {
                        "wait_count": 2,
                        "patience": 4
                    }
                }
            },
        ),
    ],
)
def test_upgrade_checkpoint(tmpdir, old_checkpoint, new_checkpoint):
    filepath = os.path.join(tmpdir, "model.ckpt")
    torch.save(old_checkpoint, filepath)
    upgrade_checkpoint(filepath)
    updated_checkpoint = torch.load(filepath)
    assert updated_checkpoint == new_checkpoint