# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 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.

"""Base TestCase for testing Providers."""

import copy

from qiskit.test.mock import FakeOurense
from qiskit.test.mock import FakeProvider
from qiskit.test import QiskitTestCase
from qiskit.providers.exceptions import BackendPropertyError


class BackendpropertiesTestCase(QiskitTestCase):
    """Test usability methods of backend.properties()."""

    backend = FakeOurense()
    backend_name = "fake_ourense"

    def setUp(self):
        super().setUp()
        self.provider = FakeProvider()
        self.backend = self.provider.get_backend("fake_ourense")
        self.properties = self.backend.properties()
        self.ref_gate = next(
            g for g in self.backend.configuration().basis_gates if g not in ["id", "rz"]
        )

    def test_gate_property(self):
        """Test for getting the gate properties."""
        self.assertEqual(
            self.properties.gate_property("cx", (0, 1), "gate_error"),
            self.properties._gates["cx"][(0, 1)]["gate_error"],
        )
        self.assertEqual(self.properties.gate_property("cx"), self.properties._gates["cx"])

        with self.assertRaises(BackendPropertyError):
            self.properties.gate_property(self.ref_gate, None, "gate_error")

    def test_gate_error(self):
        """Test for getting the gate errors."""
        self.assertEqual(
            self.properties.gate_error(self.ref_gate, 1),
            self.properties._gates[self.ref_gate][(1,)]["gate_error"][0],
        )
        self.assertEqual(
            self.properties.gate_error(
                self.ref_gate,
                [
                    2,
                ],
            ),
            self.properties._gates[self.ref_gate][(2,)]["gate_error"][0],
        )
        self.assertEqual(
            self.properties.gate_error("cx", [0, 1]),
            self.properties._gates["cx"][(0, 1)]["gate_error"][0],
        )

        with self.assertRaises(BackendPropertyError):
            self.properties.gate_error("cx", 0)

    def test_gate_length(self):
        """Test for getting the gate duration."""
        self.assertEqual(
            self.properties.gate_length(self.ref_gate, 1),
            self.properties._gates[self.ref_gate][(1,)]["gate_length"][0],
        )
        self.assertEqual(
            self.properties.gate_length("cx", [4, 3]),
            self.properties._gates["cx"][(4, 3)]["gate_length"][0],
        )

    def test_qubit_property(self):
        """Test for getting the qubit properties."""
        self.assertEqual(self.properties.qubit_property(0, "T1"), self.properties._qubits[0]["T1"])
        self.assertEqual(
            self.properties.qubit_property(0, "frequency"), self.properties._qubits[0]["frequency"]
        )
        self.assertEqual(self.properties.qubit_property(0), self.properties._qubits[0])

        with self.assertRaises(BackendPropertyError):
            self.properties.qubit_property("T1")

    def test_t1(self):
        """Test for getting the t1 of given qubit."""
        self.assertEqual(self.properties.t1(0), self.properties._qubits[0]["T1"][0])

    def test_t2(self):
        """Test for getting the t2 of a given qubit"""
        self.assertEqual(self.properties.t2(0), self.properties._qubits[0]["T2"][0])

    def test_frequency(self):
        """Test for getting the frequency of given qubit."""
        self.assertEqual(self.properties.frequency(0), self.properties._qubits[0]["frequency"][0])

    def test_readout_error(self):
        """Test for getting the readout error of given qubit."""
        self.assertEqual(
            self.properties.readout_error(0), self.properties._qubits[0]["readout_error"][0]
        )

    def test_readout_length(self):
        """Test for getting the readout length of given qubit."""
        self.assertEqual(
            self.properties.readout_length(0), self.properties._qubits[0]["readout_length"][0]
        )

    def test_apply_prefix(self):
        """Testing unit conversions."""
        self.assertEqual(
            self.properties._apply_prefix(71.9500421005539, "µs"), 7.19500421005539e-05
        )
        self.assertEqual(self.properties._apply_prefix(71.9500421005539, "ms"), 0.0719500421005539)

        with self.assertRaises(BackendPropertyError):
            self.properties._apply_prefix(71.9500421005539, "ws")

    def test_operational(self):
        """Test operation status of a given qubit."""
        self.assertTrue(self.properties.is_qubit_operational(0))

    def test_deepcopy(self):
        """Test that deepcopy creates an identical object."""
        copy_prop = copy.deepcopy(self.properties)
        self.assertEqual(copy_prop, self.properties)
