# 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 matplotlib.pylab as plt
import pandas as pd

from benchmarks.test_basic_parity import measure_loops
from tests.helpers.advanced_models import ParityModuleMNIST, ParityModuleRNN

NUM_EPOCHS = 20
NUM_RUNS = 50
MODEL_CLASSES = (ParityModuleRNN, ParityModuleMNIST)
PATH_HERE = os.path.dirname(__file__)
FIGURE_EXTENSION = ".png"


def _main():
    fig, axarr = plt.subplots(nrows=len(MODEL_CLASSES))

    for i, cls_model in enumerate(MODEL_CLASSES):
        path_csv = os.path.join(PATH_HERE, f"dump-times_{cls_model.__name__}.csv")
        if os.path.isfile(path_csv):
            df_time = pd.read_csv(path_csv, index_col=0)
        else:
            # todo: kind="Vanilla PT" -> use_lightning=False
            vanilla = measure_loops(cls_model, kind="Vanilla PT", num_epochs=NUM_EPOCHS, num_runs=NUM_RUNS)
            lightning = measure_loops(cls_model, kind="PT Lightning", num_epochs=NUM_EPOCHS, num_runs=NUM_RUNS)

            df_time = pd.DataFrame({"vanilla PT": vanilla["durations"][1:], "PT Lightning": lightning["durations"][1:]})
            df_time /= NUM_RUNS
            df_time.to_csv(os.path.join(PATH_HERE, f"dump-times_{cls_model.__name__}.csv"))
        # todo: add also relative X-axis ticks to see both: relative and absolute time differences
        df_time.plot.hist(ax=axarr[i], bins=20, alpha=0.5, title=cls_model.__name__, legend=True, grid=True)
        axarr[i].set(xlabel="time [seconds]")

    path_fig = os.path.join(PATH_HERE, f"figure-parity-times{FIGURE_EXTENSION}")
    fig.tight_layout()
    fig.savefig(path_fig)


if __name__ == "__main__":
    _main()