# MIT License

# Copyright (c) 2016 Diogo Dutra <dutradda@gmail.com>

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


import asyncio
import os.path
import zlib
from abc import ABCMeta, abstractmethod
from glob import glob
from gzip import GzipFile

import numpy as np
from myreco.exceptions import EngineError
from myreco.utils import build_engine_object_key, makedirs, run_coro
from swaggerit.utils import set_logger


class EngineObjectBase(metaclass=ABCMeta):

    def __init__(self, engine_object, data_path=None):
        self._engine_object = engine_object
        self._set_redis_key()
        set_logger(self, self._redis_key)
        if data_path is not None:
            self._set_data_path(data_path)

    def _set_redis_key(self):
        self._redis_key = build_engine_object_key(self._engine_object)

    def _set_data_path(self, data_path):
        self._data_path = os.path.join(data_path, self._redis_key)
        makedirs(self._data_path)

    def _pack_array(self, array, compress=True, level=-1):
        if compress:
            return zlib.compress(array.tobytes(), level)
        else:
            return array.tobytes()

    def _unpack_array(self, array, dtype, compress=True):
        if array is not None:
            if compress:
                return np.fromstring(zlib.decompress(array), dtype=dtype)
            else:
                return np.fromstring(array, dtype=dtype)
        else:
            return None

    @abstractmethod
    def export(self, items_model, session):
        pass

    def _build_csv_readers(self, pattern=''):
        readers = []
        pattern = os.path.join(self._data_path, '{}*.gz'.format(pattern))

        for filename in glob(pattern):
            file_ = GzipFile(filename, 'r')
            readers.append(file_)

        return readers

    async def _get_items_indices_map_dict(self, items_indices_map, session):
        items_indices_map_dict = await items_indices_map.get_all(session)

        if not items_indices_map_dict.values():
            raise EngineError(
                "The Indices Map for '{}' is empty. Please update these items"
                .format(self._engine_object['item_type']['name']))

        return items_indices_map_dict

    def _run_coro(self, coro, session):
        return run_coro(coro, session)
    
    @abstractmethod
    def get_data(self, items_model, session):
        pass

    def _log_get_data_started(self):
        self._logger.info("Started import data")

    def _log_get_data_finished(self):
        self._logger.info("Finished import data")
