#  =========================================================================  #
#   Copyright 2018 National Technology & Engineering Solutions of Sandia,
#   LLC (NTESS). Under the terms of Contract DE-NA0003525 with NTESS,
#   the U.S. Government retains certain rights in this software.
#
#   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.
#  =========================================================================  #

from ..gate_parent_class import LogicalGate
from ..helper_functions import expected_params


class GateIdentity(LogicalGate):
    """
    Logical Identity.

    This is equivalent to ``distance`` number of syndrome of extraction rounds.
    """

    def __init__(self, qecc, symbol, **gate_params):
        """

        Args:
            qecc(QECC):
            symbol(str):
            **gate_params(dict): kwargs including keys: 'num_syn_extract' (default: qecc.distance)
        """
        super().__init__(qecc, symbol, **gate_params)

        expected_params(gate_params, {'num_syn_extract', 'error_free', 'random_outcome'})

        self.num_syn_extract = gate_params.get('num_syn_extract', qecc.distance)

        # This specifies the logical instructions used for the gate.
        self.instr_symbols = ['instr_syn_extract'] * self.num_syn_extract


class GateInitZero(LogicalGate):
    """
    Initialize logical state zero.
    """

    def __init__(self, qecc, symbol, **gate_params):
        """

        Args:
            qecc(QECC):
            symbol(str):
            **gate_params(dict): kwargs including keys: 'num_syn_extract' (default: 0)
        """
        super().__init__(qecc, symbol, **gate_params)

        expected_params(gate_params, {'num_syn_extract', 'error_free', 'random_outcome'})

        self.num_syn_extract = gate_params.get('num_syn_extract', 0)

        # This specifies the logical instructions used for the gate.
        self.instr_symbols = ['instr_init_zero']
        syn_extract = ['instr_syn_extract'] * self.num_syn_extract
        self.instr_symbols.extend(syn_extract)


class GateInitPlus(LogicalGate):
    """
    Initialize logical state plus.
    """

    def __init__(self, qecc, symbol, **gate_params):
        """

        Args:
            qecc(QECC):
            symbol(str):
            **gate_params(dict): kwargs including keys: 'num_syn_extract' (default: 0)
        """
        super().__init__(qecc, symbol, **gate_params)

        expected_params(gate_params, {'num_syn_extract', 'error_free', 'random_outcome'})

        self.num_syn_extract = gate_params.get('num_syn_extract', 0)

        # This specifies the logical instructions used for the gate.
        self.instr_symbols = ['instr_init_plus']
        syn_extract = ['instr_syn_extract'] * self.num_syn_extract
        self.instr_symbols.extend(syn_extract)
