# -*- coding: utf-8 -*-

# This code is part of Qiskit.
#
# (C) Copyright IBM 2018, 2019.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

"""
This module implements the abstract base class for algorithm modules.

To create add-on algorithm modules subclass the QuantumAlgorithm
class in this module.
Doing so requires that the required algorithm interface is implemented.
"""

from abc import abstractmethod
import logging
from qiskit.providers import BaseBackend
from qiskit.aqua import aqua_globals, Pluggable, QuantumInstance, AquaError

logger = logging.getLogger(__name__)


class QuantumAlgorithm(Pluggable):
    """
    Base class for Algorithms.

    This method should initialize the module and its configuration, and
    use an exception if a component of the module is available.
    """
    @abstractmethod
    def __init__(self):
        super().__init__()
        self._quantum_instance = None

    @property
    def random(self):
        """Return a numpy random."""
        return aqua_globals.random

    def run(self, quantum_instance=None, **kwargs):
        """Execute the algorithm with selected backend.

        Args:
            quantum_instance (QuantumInstance or BaseBackend): the experiemental setting.

        Returns:
            dict: results of an algorithm.
        """
        if not self.configuration.get('classical', False):
            if quantum_instance is None:
                AquaError("Quantum device or backend is needed since you are running quantum algorithm.")
            if isinstance(quantum_instance, BaseBackend):
                quantum_instance = QuantumInstance(quantum_instance)
                quantum_instance.set_config(**kwargs)
            self._quantum_instance = quantum_instance
        return self._run()

    @abstractmethod
    def _run(self):
        raise NotImplementedError()

    @property
    def quantum_instance(self):
        return self._quantum_instance

@@ -791,49 +791,8 @@
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@@ -1623,24 +1623,74 @@
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Fix qiskit import errors