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

# Copyright 2019 IBM.
#
# 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 unittest
from qiskit import BasicAer, QuantumCircuit, QuantumRegister
from qiskit.aqua import QuantumInstance
from qiskit.aqua.components.oracles import CustomCircuitOracle
from qiskit.aqua.algorithms import DeutschJozsa
from test.common import QiskitAquaTestCase


class TestCustomCircuitOracle(QiskitAquaTestCase):

    def test_using_dj_with_constant_func(self):
        qv = QuantumRegister(2, name='v')
        qo = QuantumRegister(1, name='o')
        circuit = QuantumCircuit(qv, qo)
        circuit.x(qo[0])

        oracle = CustomCircuitOracle(variable_register=qv, output_register=qo, circuit=circuit)
        algorithm = DeutschJozsa(oracle)
        result = algorithm.run(quantum_instance=QuantumInstance(BasicAer.get_backend('qasm_simulator')))
        self.assertTrue(result['result'] == 'constant')

    def test_using_dj_with_balanced_func(self):
        qv = QuantumRegister(2, name='v')
        qo = QuantumRegister(1, name='o')
        circuit = QuantumCircuit(qv, qo)
        circuit.cx(qv[0], qo[0])

        oracle = CustomCircuitOracle(variable_register=qv, output_register=qo, circuit=circuit)
        algorithm = DeutschJozsa(oracle)
        result = algorithm.run(quantum_instance=QuantumInstance(BasicAer.get_backend('qasm_simulator')))
        self.assertTrue(result['result'] == 'balanced')


if __name__ == '__main__':
    unittest.main()
