# Copyright 2020 Huawei Technologies Co., Ltd
#
# 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.
# ============================================================================
"""
Data operations, will be used in train.py and eval.py
"""
import os

import numpy as np

from imdb import ImdbParser
import mindspore.dataset as ds
from mindspore.mindrecord import FileWriter


def create_dataset(data_home, batch_size, repeat_num=1, training=True):
    """Data operations."""
    ds.config.set_seed(1)
    data_dir = os.path.join(data_home, "aclImdb_train.mindrecord0")
    if not training:
        data_dir = os.path.join(data_home, "aclImdb_test.mindrecord0")

    data_set = ds.MindDataset(data_dir, columns_list=["feature", "label"], num_parallel_workers=4)

    # apply map operations on images
    data_set = data_set.shuffle(buffer_size=data_set.get_dataset_size())
    data_set = data_set.batch(batch_size=batch_size, drop_remainder=True)
    data_set = data_set.repeat(count=repeat_num)

    return data_set


def _convert_to_mindrecord(data_home, features, labels, weight_np=None, training=True):
    """
    convert imdb dataset to mindrecoed dataset
    """
    if weight_np is not None:
        np.savetxt(os.path.join(data_home, 'weight.txt'), weight_np)

    # write mindrecord
    schema_json = {"id": {"type": "int32"},
                   "label": {"type": "int32"},
                   "feature": {"type": "int32", "shape": [-1]}}

    data_dir = os.path.join(data_home, "aclImdb_train.mindrecord")
    if not training:
        data_dir = os.path.join(data_home, "aclImdb_test.mindrecord")

    def get_imdb_data(features, labels):
        data_list = []
        for i, (label, feature) in enumerate(zip(labels, features)):
            data_json = {"id": i,
                         "label": int(label),
                         "feature": feature.reshape(-1)}
            data_list.append(data_json)
        return data_list

    writer = FileWriter(data_dir, shard_num=4)
    data = get_imdb_data(features, labels)
    writer.add_schema(schema_json, "nlp_schema")
    writer.add_index(["id", "label"])
    writer.write_raw_data(data)
    writer.commit()


def convert_to_mindrecord(embed_size, aclimdb_path, preprocess_path, glove_path):
    """
    convert imdb dataset to mindrecoed dataset
    """
    parser = ImdbParser(aclimdb_path, glove_path, embed_size)
    parser.parse()

    if not os.path.exists(preprocess_path):
        print(f"preprocess path {preprocess_path} is not exist")
        os.makedirs(preprocess_path)

    train_features, train_labels, train_weight_np = parser.get_datas('train')
    _convert_to_mindrecord(preprocess_path, train_features, train_labels, train_weight_np)

    test_features, test_labels, _ = parser.get_datas('test')
    _convert_to_mindrecord(preprocess_path, test_features, test_labels, training=False)