from __future__ import annotations

import math
from typing import TYPE_CHECKING, Dict, Generator, Optional, Union

import netsquid as ns
from netqasm.lang.instr import NetQASMInstruction, core, nv, vanilla
from netqasm.lang.operand import Register
from netqasm.lang.subroutine import Subroutine
from netsquid.components import QuantumProcessor
from netsquid.components.component import Component, Port
from netsquid.components.instructions import (
    INSTR_CNOT,
    INSTR_CXDIR,
    INSTR_CYDIR,
    INSTR_CZ,
    INSTR_H,
    INSTR_INIT,
    INSTR_MEASURE,
    INSTR_ROT_X,
    INSTR_ROT_Y,
    INSTR_ROT_Z,
    INSTR_X,
    INSTR_Y,
    INSTR_Z,
)
from netsquid.components.instructions import Instruction as NsInstr
from netsquid.components.qprogram import QuantumProgram
from netsquid.nodes import Node
from netsquid.qubits import qubitapi

from pydynaa import EventExpression
from squidasm.sim.stack.common import (
    AllocError,
    AppMemory,
    ComponentProtocol,
    NetstackBreakpointCreateRequest,
    NetstackBreakpointReceiveRequest,
    NetstackCreateRequest,
    NetstackReceiveRequest,
    PhysicalQuantumMemory,
    PortListener,
)
from squidasm.sim.stack.globals import GlobalSimData
from squidasm.sim.stack.signals import (
    SIGNAL_HAND_PROC_MSG,
    SIGNAL_MEMORY_FREED,
    SIGNAL_NSTK_PROC_MSG,
)

if TYPE_CHECKING:
    from squidasm.sim.stack.qnos import Qnos

PI = math.pi
PI_OVER_2 = math.pi / 2


class ProcessorComponent(Component):
    """NetSquid component representing a QNodeOS processor.

    Subcomponent of a QnosComponent.

    Has communications ports with
     - the netstack component of this QNodeOS
     - the handler compmonent of this QNodeOS

    This is a static container for processor-related components and ports.
    Behavior of a QNodeOS processor is modeled in the `Processor` class,
    which is a subclass of `Protocol`.
    """

    def __init__(self, node: Node) -> None:
        super().__init__(f"{node.name}_processor")
        self._node = node
        self.add_ports(["nstk_out", "nstk_in"])
        self.add_ports(["hand_out", "hand_in"])

    @property
    def netstack_in_port(self) -> Port:
        return self.ports["nstk_in"]

    @property
    def netstack_out_port(self) -> Port:
        return self.ports["nstk_out"]

    @property
    def handler_in_port(self) -> Port:
        return self.ports["hand_in"]

    @property
    def handler_out_port(self) -> Port:
        return self.ports["hand_out"]

    @property
    def qdevice(self) -> QuantumProcessor:
        return self.supercomponent.qdevice

    @property
    def node(self) -> Node:
        return self._node


class Processor(ComponentProtocol):
    """NetSquid protocol representing a QNodeOS processor."""

    def __init__(self, comp: ProcessorComponent, qnos: Qnos) -> None:
        """Processor protocol constructor. Typically created indirectly through
        constructing a `Qnos` instance.

        :param comp: NetSquid component representing the processor
        :param qnos: `Qnos` protocol that owns this protocol
        """
        super().__init__(name=f"{comp.name}_protocol", comp=comp)
        self._comp = comp
        self._qnos = qnos

        self.add_listener(
            "handler",
            PortListener(self._comp.ports["hand_in"], SIGNAL_HAND_PROC_MSG),
        )
        self.add_listener(
            "netstack",
            PortListener(self._comp.ports["nstk_in"], SIGNAL_NSTK_PROC_MSG),
        )

        self.add_signal(SIGNAL_MEMORY_FREED)

    @property
    def app_memories(self) -> Dict[int, AppMemory]:
        """Get a dictionary of app IDs to application memories."""
        return self._qnos.app_memories

    @property
    def physical_memory(self) -> PhysicalQuantumMemory:
        """Get the physical quantum memory object."""
        return self._qnos.physical_memory

    @property
    def qdevice(self) -> QuantumProcessor:
        """Get the NetSquid `QuantumProcessor` object of this node."""
        return self._comp.qdevice

    def _send_handler_msg(self, msg: str) -> None:
        self._comp.handler_out_port.tx_output(msg)

    def _receive_handler_msg(self) -> Generator[EventExpression, None, str]:
        return (yield from self._receive_msg("handler", SIGNAL_HAND_PROC_MSG))

    def _send_netstack_msg(self, msg: str) -> None:
        self._comp.netstack_out_port.tx_output(msg)

    def _receive_netstack_msg(self) -> Generator[EventExpression, None, str]:
        return (yield from self._receive_msg("netstack", SIGNAL_NSTK_PROC_MSG))

    def _flush_netstack_msgs(self) -> None:
        self._listeners["netstack"].buffer.clear()

    def run(self) -> Generator[EventExpression, None, None]:
        """Run this protocol. Automatically called by NetSquid during simulation."""
        while True:
            subroutine = yield from self._receive_handler_msg()
            # assert isinstance(subroutine, Subroutine)
            self._logger.debug(f"received new subroutine from handler: {subroutine}")

            yield from self.execute_subroutine(subroutine)

            self._send_handler_msg("subroutine done")

    def execute_subroutine(
        self, subroutine: Subroutine
    ) -> Generator[EventExpression, None, None]:
        """Execute a NetQASM subroutine on this processor."""
        app_id = subroutine.app_id
        assert app_id in self.app_memories
        app_mem = self.app_memories[app_id]
        app_mem.set_prog_counter(0)
        while app_mem.prog_counter < len(subroutine.instructions):
            instr = subroutine.instructions[app_mem.prog_counter]
            self._logger.debug(
                f"{ns.sim_time()} interpreting instruction {instr} at line {app_mem.prog_counter}"
            )

            if (
                isinstance(instr, core.JmpInstruction)
                or isinstance(instr, core.BranchUnaryInstruction)
                or isinstance(instr, core.BranchBinaryInstruction)
            ):
                self._interpret_branch_instr(app_id, instr)
            else:
                generator = self._interpret_instruction(app_id, instr)
                if generator:
                    yield from generator
                app_mem.increment_prog_counter()

    def _interpret_instruction(
        self, app_id: int, instr: NetQASMInstruction
    ) -> Optional[Generator[EventExpression, None, None]]:
        if isinstance(instr, core.SetInstruction):
            return self._interpret_set(app_id, instr)
        elif isinstance(instr, core.QAllocInstruction):
            return self._interpret_qalloc(app_id, instr)
        elif isinstance(instr, core.QFreeInstruction):
            return self._interpret_qfree(app_id, instr)
        elif isinstance(instr, core.StoreInstruction):
            return self._interpret_store(app_id, instr)
        elif isinstance(instr, core.LoadInstruction):
            return self._interpret_load(app_id, instr)
        elif isinstance(instr, core.LeaInstruction):
            return self._interpret_lea(app_id, instr)
        elif isinstance(instr, core.UndefInstruction):
            return self._interpret_undef(app_id, instr)
        elif isinstance(instr, core.ArrayInstruction):
            return self._interpret_array(app_id, instr)
        elif isinstance(instr, core.InitInstruction):
            return self._interpret_init(app_id, instr)
        elif isinstance(instr, core.MeasInstruction):
            return self._interpret_meas(app_id, instr)
        elif isinstance(instr, core.CreateEPRInstruction):
            return self._interpret_create_epr(app_id, instr)
        elif isinstance(instr, core.RecvEPRInstruction):
            return self._interpret_recv_epr(app_id, instr)
        elif isinstance(instr, core.WaitAllInstruction):
            return self._interpret_wait_all(app_id, instr)
        elif isinstance(instr, core.RetRegInstruction):
            pass
        elif isinstance(instr, core.RetArrInstruction):
            pass
        elif isinstance(instr, core.SingleQubitInstruction):
            return self._interpret_single_qubit_instr(app_id, instr)
        elif isinstance(instr, core.TwoQubitInstruction):
            return self._interpret_two_qubit_instr(app_id, instr)
        elif isinstance(instr, core.RotationInstruction):
            return self._interpret_single_rotation_instr(app_id, instr)
        elif isinstance(instr, core.ControlledRotationInstruction):
            return self._interpret_controlled_rotation_instr(app_id, instr)
        elif isinstance(instr, core.ClassicalOpInstruction) or isinstance(
            instr, core.ClassicalOpModInstruction
        ):
            return self._interpret_binary_classical_instr(app_id, instr)
        elif isinstance(instr, core.BreakpointInstruction):
            return self._interpret_breakpoint(app_id, instr)
        else:
            raise RuntimeError(f"Invalid instruction {instr}")

    def _interpret_breakpoint(
        self, app_id: int, instr: core.BreakpointInstruction
    ) -> None:
        if instr.action.value == 0:
            self._logger.info("BREAKPOINT: no action taken")
        elif instr.action.value == 1:
            self._logger.info("BREAKPOINT: dumping local state:")
            for i in range(self.qdevice.num_positions):
                if self.qdevice.mem_positions[i].in_use:
                    q = self.qdevice.peek(i, skip_noise=True)
                    qstate = qubitapi.reduced_dm(q)
                    self._logger.info(f"physical qubit {i}:\n{qstate}")

            GlobalSimData.get_quantum_state(save=True)  # TODO: rewrite this
        elif instr.action.value == 2:
            self._logger.info("BREAKPOINT: dumping global state:")
            if instr.role.value == 0:
                self._send_netstack_msg(NetstackBreakpointCreateRequest(app_id))
                ready = yield from self._receive_netstack_msg()
                assert ready == "breakpoint ready"

                state = GlobalSimData.get_quantum_state(save=True)
                self._logger.info(state)

                self._send_netstack_msg("breakpoint end")
                finished = yield from self._receive_netstack_msg()
                assert finished == "breakpoint finished"
            elif instr.role.value == 1:
                self._send_netstack_msg(NetstackBreakpointReceiveRequest(app_id))
                ready = yield from self._receive_netstack_msg()
                assert ready == "breakpoint ready"
                self._send_netstack_msg("breakpoint end")
                finished = yield from self._receive_netstack_msg()
                assert finished == "breakpoint finished"
            else:
                raise ValueError
        else:
            raise ValueError

    def _interpret_set(self, app_id: int, instr: core.SetInstruction) -> None:
        self._logger.debug(f"Set register {instr.reg} to {instr.imm}")
        self.app_memories[app_id].set_reg_value(instr.reg, instr.imm.value)

    def _interpret_qalloc(self, app_id: int, instr: core.QAllocInstruction) -> None:
        app_mem = self.app_memories[app_id]

        virt_id = app_mem.get_reg_value(instr.reg)
        if virt_id is None:
            raise RuntimeError(f"qubit address in register {instr.reg} is not defined")
        self._logger.debug(f"Allocating qubit with virtual ID {virt_id}")

        phys_id = self.physical_memory.allocate()
        app_mem.map_virt_id(virt_id, phys_id)

    def _interpret_qfree(self, app_id: int, instr: core.QFreeInstruction) -> None:
        app_mem = self.app_memories[app_id]

        virt_id = app_mem.get_reg_value(instr.reg)
        assert virt_id is not None
        self._logger.debug(f"Freeing virtual qubit {virt_id}")
        phys_id = app_mem.phys_id_for(virt_id)
        assert phys_id is not None
        app_mem.unmap_virt_id(virt_id)
        self.physical_memory.free(phys_id)
        self.send_signal(SIGNAL_MEMORY_FREED)
        self.qdevice.mem_positions[phys_id].in_use = False

    def _interpret_store(self, app_id: int, instr: core.StoreInstruction) -> None:
        app_mem = self.app_memories[app_id]

        value = app_mem.get_reg_value(instr.reg)
        if value is None:
            raise RuntimeError(f"value in register {instr.reg} is not defined")
        self._logger.debug(
            f"Storing value {value} from register {instr.reg} "
            f"to array entry {instr.entry}"
        )

        app_mem.set_array_entry(instr.entry, value)

    def _interpret_load(self, app_id: int, instr: core.LoadInstruction) -> None:
        app_mem = self.app_memories[app_id]

        value = app_mem.get_array_entry(instr.entry)
        if value is None:
            raise RuntimeError(f"array value at {instr.entry} is not defined")
        self._logger.debug(
            f"Storing value {value} from array entry {instr.entry} "
            f"to register {instr.reg}"
        )

        app_mem.set_reg_value(instr.reg, value)

    def _interpret_lea(self, app_id: int, instr: core.LeaInstruction) -> None:
        app_mem = self.app_memories[app_id]
        self._logger.debug(
            f"Storing address of {instr.address} to register {instr.reg}"
        )
        app_mem.set_reg_value(instr.reg, instr.address.address)

    def _interpret_undef(self, app_id: int, instr: core.UndefInstruction) -> None:
        app_mem = self.app_memories[app_id]
        self._logger.debug(f"Unset array entry {instr.entry}")
        app_mem.set_array_entry(instr.entry, None)

    def _interpret_array(self, app_id: int, instr: core.ArrayInstruction) -> None:
        app_mem = self.app_memories[app_id]

        length = app_mem.get_reg_value(instr.size)
        assert length is not None
        self._logger.debug(
            f"Initializing an array of length {length} at address {instr.address}"
        )

        app_mem.init_new_array(instr.address.address, length)

    def _interpret_branch_instr(
        self,
        app_id: int,
        instr: Union[
            core.BranchUnaryInstruction,
            core.BranchBinaryInstruction,
            core.JmpInstruction,
        ],
    ) -> None:
        app_mem = self.app_memories[app_id]
        a, b = None, None
        registers = []
        if isinstance(instr, core.BranchUnaryInstruction):
            a = app_mem.get_reg_value(instr.reg)
            registers = [instr.reg]
        elif isinstance(instr, core.BranchBinaryInstruction):
            a = app_mem.get_reg_value(instr.reg0)
            b = app_mem.get_reg_value(instr.reg1)
            registers = [instr.reg0, instr.reg1]

        if isinstance(instr, core.JmpInstruction):
            condition = True
        elif isinstance(instr, core.BranchUnaryInstruction):
            condition = instr.check_condition(a)
        elif isinstance(instr, core.BranchBinaryInstruction):
            condition = instr.check_condition(a, b)

        if condition:
            jump_address = instr.line
            self._logger.debug(
                f"Branching to line {jump_address}, since {instr}(a={a}, b={b}) "
                f"is True, with values from registers {registers}"
            )
            app_mem.set_prog_counter(jump_address.value)
        else:
            self._logger.debug(
                f"Don't branch, since {instr}(a={a}, b={b}) "
                f"is False, with values from registers {registers}"
            )
            app_mem.increment_prog_counter()

    def _interpret_binary_classical_instr(
        self,
        app_id: int,
        instr: Union[
            core.ClassicalOpInstruction,
            core.ClassicalOpModInstruction,
        ],
    ) -> None:
        app_mem = self.app_memories[app_id]
        mod = None
        if isinstance(instr, core.ClassicalOpModInstruction):
            mod = app_mem.get_reg_value(instr.regmod)
        if mod is not None and mod < 1:
            raise RuntimeError(f"Modulus needs to be greater or equal to 1, not {mod}")
        a = app_mem.get_reg_value(instr.regin0)
        b = app_mem.get_reg_value(instr.regin1)
        assert a is not None
        assert b is not None
        value = self._compute_binary_classical_instr(instr, a, b, mod=mod)
        mod_str = "" if mod is None else f"(mod {mod})"
        self._logger.debug(
            f"Performing {instr} of a={a} and b={b} {mod_str} "
            f"and storing the value {value} at register {instr.regout}"
        )
        app_mem.set_reg_value(instr.regout, value)

    def _compute_binary_classical_instr(
        self, instr: NetQASMInstruction, a: int, b: int, mod: Optional[int] = 1
    ) -> int:
        if isinstance(instr, core.AddInstruction):
            return a + b
        elif isinstance(instr, core.AddmInstruction):
            assert mod is not None
            return (a + b) % mod
        elif isinstance(instr, core.SubInstruction):
            return a - b
        elif isinstance(instr, core.SubmInstruction):
            assert mod is not None
            return (a - b) % mod
        else:
            raise ValueError(f"{instr} cannot be used as binary classical function")

    def _interpret_init(
        self, app_id: int, instr: core.InitInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError

    def _do_single_rotation(
        self,
        app_id: int,
        instr: core.RotationInstruction,
        ns_instr: NsInstr,
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.reg)
        phys_id = app_mem.phys_id_for(virt_id)
        angle = self._get_rotation_angle_from_operands(
            n=instr.angle_num.value,
            d=instr.angle_denom.value,
        )
        self._logger.debug(
            f"Performing {instr} with angle {angle} on virtual qubit "
            f"{virt_id} (physical ID: {phys_id})"
        )
        prog = QuantumProgram()
        prog.apply(ns_instr, qubit_indices=[phys_id], angle=angle)
        yield self.qdevice.execute_program(prog)

    def _interpret_single_rotation_instr(
        self, app_id: int, instr: nv.RotXInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError

    def _do_controlled_rotation(
        self,
        app_id: int,
        instr: core.ControlledRotationInstruction,
        ns_instr: NsInstr,
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id0 = app_mem.get_reg_value(instr.reg0)
        phys_id0 = app_mem.phys_id_for(virt_id0)
        virt_id1 = app_mem.get_reg_value(instr.reg1)
        phys_id1 = app_mem.phys_id_for(virt_id1)
        angle = self._get_rotation_angle_from_operands(
            n=instr.angle_num.value,
            d=instr.angle_denom.value,
        )
        self._logger.debug(
            f"Performing {instr} with angle {angle} on virtual qubits "
            f"{virt_id0} and {virt_id1} (physical IDs: {phys_id0} and {phys_id1})"
        )
        prog = QuantumProgram()
        prog.apply(ns_instr, qubit_indices=[phys_id0, phys_id1], angle=angle)
        yield self.qdevice.execute_program(prog)

    def _interpret_controlled_rotation_instr(
        self, app_id: int, instr: core.ControlledRotationInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError

    def _get_rotation_angle_from_operands(self, n: int, d: int) -> float:
        return float(n * PI / (2**d))

    def _interpret_meas(
        self, app_id: int, instr: core.MeasInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError

    def _interpret_create_epr(
        self, app_id: int, instr: core.CreateEPRInstruction
    ) -> None:
        app_mem = self.app_memories[app_id]
        remote_node_id = app_mem.get_reg_value(instr.remote_node_id)
        epr_socket_id = app_mem.get_reg_value(instr.epr_socket_id)
        qubit_array_addr = app_mem.get_reg_value(instr.qubit_addr_array)
        arg_array_addr = app_mem.get_reg_value(instr.arg_array)
        result_array_addr = app_mem.get_reg_value(instr.ent_results_array)
        assert remote_node_id is not None
        assert epr_socket_id is not None
        # qubit_array_addr can be None
        assert arg_array_addr is not None
        assert result_array_addr is not None
        self._logger.debug(
            f"Creating EPR pair with remote node id {remote_node_id} "
            f"and EPR socket ID {epr_socket_id}, "
            f"using qubit addresses stored in array with address {qubit_array_addr}, "
            f"using arguments stored in array with address {arg_array_addr}, "
            f"placing the entanglement information in array at "
            f"address {result_array_addr}"
        )

        msg = NetstackCreateRequest(
            app_id,
            remote_node_id,
            epr_socket_id,
            qubit_array_addr,
            arg_array_addr,
            result_array_addr,
        )
        self._send_netstack_msg(msg)
        # result = yield from self._receive_netstack_msg()
        # self._logger.debug(f"result from netstack: {result}")

    def _interpret_recv_epr(self, app_id: int, instr: core.RecvEPRInstruction) -> None:
        app_mem = self.app_memories[app_id]
        remote_node_id = app_mem.get_reg_value(instr.remote_node_id)
        epr_socket_id = app_mem.get_reg_value(instr.epr_socket_id)
        qubit_array_addr = app_mem.get_reg_value(instr.qubit_addr_array)
        result_array_addr = app_mem.get_reg_value(instr.ent_results_array)
        assert remote_node_id is not None
        assert epr_socket_id is not None
        # qubit_array_addr can be None
        assert result_array_addr is not None
        self._logger.debug(
            f"Receiving EPR pair with remote node id {remote_node_id} "
            f"and EPR socket ID {epr_socket_id}, "
            f"using qubit addresses stored in array with address {qubit_array_addr}, "
            f"placing the entanglement information in array at "
            f"address {result_array_addr}"
        )

        msg = NetstackReceiveRequest(
            app_id,
            remote_node_id,
            epr_socket_id,
            qubit_array_addr,
            result_array_addr,
        )
        self._send_netstack_msg(msg)
        # result = yield from self._receive_netstack_msg()
        # self._logger.debug(f"result from netstack: {result}")

    def _interpret_wait_all(
        self, app_id: int, instr: core.WaitAllInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        self._logger.debug(
            f"Waiting for all entries in array slice {instr.slice} to become defined"
        )
        assert isinstance(instr.slice.start, Register)
        assert isinstance(instr.slice.stop, Register)
        start: int = app_mem.get_reg_value(instr.slice.start)
        end: int = app_mem.get_reg_value(instr.slice.stop)
        addr: int = instr.slice.address.address

        self._logger.debug(
            f"checking if @{addr}[{start}:{end}] has values for app ID {app_id}"
        )

        while True:
            values = self.app_memories[app_id].get_array_values(addr, start, end)
            if any(v is None for v in values):
                self._logger.debug(
                    f"waiting for netstack to write to @{addr}[{start}:{end}] "
                    f"for app ID {app_id}"
                )
                yield from self._receive_netstack_msg()
                self._logger.debug("netstack wrote something")
            else:
                break
        self._flush_netstack_msgs()
        self._logger.debug("all entries were written")

        self._logger.info(f"\nFinished waiting for array slice {instr.slice}")

    def _interpret_ret_reg(self, app_id: int, instr: core.RetRegInstruction) -> None:
        pass

    def _interpret_ret_arr(self, app_id: int, instr: core.RetArrInstruction) -> None:
        pass

    def _interpret_single_qubit_instr(
        self, app_id: int, instr: core.SingleQubitInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError

    def _interpret_two_qubit_instr(
        self, app_id: int, instr: core.SingleQubitInstruction
    ) -> Generator[EventExpression, None, None]:
        raise NotImplementedError


class GenericProcessor(Processor):
    """A `Processor` for nodes with a generic quantum hardware."""

    def _interpret_init(
        self, app_id: int, instr: core.InitInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.reg)
        phys_id = app_mem.phys_id_for(virt_id)
        self._logger.debug(
            f"Performing {instr} on virtual qubit "
            f"{virt_id} (physical ID: {phys_id})"
        )
        prog = QuantumProgram()
        prog.apply(INSTR_INIT, qubit_indices=[phys_id])
        yield self.qdevice.execute_program(prog)

    def _interpret_meas(
        self, app_id: int, instr: core.MeasInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.qreg)
        phys_id = app_mem.phys_id_for(virt_id)

        self._logger.debug(
            f"Measuring qubit {virt_id} (physical ID: {phys_id}), "
            f"placing the outcome in register {instr.creg}"
        )

        prog = QuantumProgram()
        prog.apply(INSTR_MEASURE, qubit_indices=[phys_id])
        yield self.qdevice.execute_program(prog)
        outcome: int = prog.output["last"][0]
        app_mem.set_reg_value(instr.creg, outcome)

    def _interpret_single_qubit_instr(
        self, app_id: int, instr: core.SingleQubitInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.qreg)
        phys_id = app_mem.phys_id_for(virt_id)
        if isinstance(instr, vanilla.GateXInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_X, qubit_indices=[phys_id])
            yield self.qdevice.execute_program(prog)
        elif isinstance(instr, vanilla.GateYInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_Y, qubit_indices=[phys_id])
            yield self.qdevice.execute_program(prog)
        elif isinstance(instr, vanilla.GateZInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_Z, qubit_indices=[phys_id])
            yield self.qdevice.execute_program(prog)
        elif isinstance(instr, vanilla.GateHInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_H, qubit_indices=[phys_id])
            yield self.qdevice.execute_program(prog)
        else:
            raise RuntimeError(f"Unsupported instruction {instr}")

    def _interpret_single_rotation_instr(
        self, app_id: int, instr: nv.RotXInstruction
    ) -> Generator[EventExpression, None, None]:
        if isinstance(instr, vanilla.RotXInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_X)
        elif isinstance(instr, vanilla.RotYInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_Y)
        elif isinstance(instr, vanilla.RotZInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_Z)
        else:
            raise RuntimeError(f"Unsupported instruction {instr}")

    def _interpret_controlled_rotation_instr(
        self, app_id: int, instr: core.ControlledRotationInstruction
    ) -> Generator[EventExpression, None, None]:
        raise RuntimeError(f"Unsupported instruction {instr}")

    def _interpret_two_qubit_instr(
        self, app_id: int, instr: core.SingleQubitInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id0 = app_mem.get_reg_value(instr.reg0)
        phys_id0 = app_mem.phys_id_for(virt_id0)
        virt_id1 = app_mem.get_reg_value(instr.reg1)
        phys_id1 = app_mem.phys_id_for(virt_id1)
        if isinstance(instr, vanilla.CnotInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_CNOT, qubit_indices=[phys_id0, phys_id1])
            yield self.qdevice.execute_program(prog)
        elif isinstance(instr, vanilla.CphaseInstruction):
            prog = QuantumProgram()
            prog.apply(INSTR_CZ, qubit_indices=[phys_id0, phys_id1])
            yield self.qdevice.execute_program(prog)
        else:
            raise RuntimeError(f"Unsupported instruction {instr}")


class NVProcessor(Processor):
    """A `Processor` for nodes with a NV hardware."""

    def _interpret_qalloc(self, app_id: int, instr: core.QAllocInstruction) -> None:
        app_mem = self.app_memories[app_id]

        virt_id = app_mem.get_reg_value(instr.reg)
        if virt_id is None:
            raise RuntimeError(f"qubit address in register {instr.reg} is not defined")
        self._logger.debug(f"Allocating qubit with virtual ID {virt_id}")

        # Virtual ID > 0 corresponds to memory qubits
        if virt_id > 0:
            phys_id = self.physical_memory.allocate_mem()
        else:
            phys_id = self.physical_memory.allocate_comm()
        app_mem.map_virt_id(virt_id, phys_id)

    def _interpret_init(
        self, app_id: int, instr: core.InitInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.reg)
        phys_id = app_mem.phys_id_for(virt_id)
        self._logger.debug(
            f"Performing {instr} on virtual qubit "
            f"{virt_id} (physical ID: {phys_id})"
        )
        prog = QuantumProgram()
        prog.apply(INSTR_INIT, qubit_indices=[phys_id])
        yield self.qdevice.execute_program(prog)

    def _measure_electron(self) -> Generator[EventExpression, None, int]:
        prog = QuantumProgram()
        prog.apply(INSTR_MEASURE, qubit_indices=[0])
        yield self.qdevice.execute_program(prog)
        outcome: int = prog.output["last"][0]
        return outcome

    def _move_carbon_to_electron_for_measure(
        self, carbon_id: int
    ) -> Generator[EventExpression, None, None]:
        prog = QuantumProgram()
        prog.apply(INSTR_INIT, qubit_indices=[0])
        prog.apply(INSTR_ROT_Y, qubit_indices=[0], angle=PI_OVER_2)
        prog.apply(INSTR_CYDIR, qubit_indices=[0, carbon_id], angle=-PI_OVER_2)
        prog.apply(INSTR_ROT_X, qubit_indices=[0], angle=-PI_OVER_2)
        prog.apply(INSTR_CXDIR, qubit_indices=[0, carbon_id], angle=PI_OVER_2)
        prog.apply(INSTR_ROT_Y, qubit_indices=[0], angle=-PI_OVER_2)
        yield self.qdevice.execute_program(prog)

    def _move_electron_to_carbon(
        self, carbon_id: int
    ) -> Generator[EventExpression, None, None]:
        prog = QuantumProgram()
        prog.apply(INSTR_INIT, qubit_indices=[carbon_id])
        prog.apply(INSTR_ROT_Y, qubit_indices=[0], angle=PI_OVER_2)
        prog.apply(INSTR_CYDIR, qubit_indices=[0, carbon_id], angle=-PI_OVER_2)
        prog.apply(INSTR_ROT_X, qubit_indices=[0], angle=-PI_OVER_2)
        prog.apply(INSTR_CXDIR, qubit_indices=[0, carbon_id], angle=PI_OVER_2)
        yield self.qdevice.execute_program(prog)

    def _interpret_meas(
        self, app_id: int, instr: core.MeasInstruction
    ) -> Generator[EventExpression, None, None]:
        app_mem = self.app_memories[app_id]
        virt_id = app_mem.get_reg_value(instr.qreg)
        phys_id = app_mem.phys_id_for(virt_id)

        # Only the electron (phys ID 0) can be measured.
        # Measuring any other physical qubit (i.e one of the carbons) requires
        # freeing up the electron and moving the target qubit to the electron first.

        if phys_id == 0:
            # Measuring the electron. This can be done immediately.
            outcome = yield from self._measure_electron()
            app_mem.set_reg_value(instr.creg, outcome)
        else:
            # We want to measure a carbon.
            # Move it to the electron first.
            if self.physical_memory.is_allocated(0):
                # Electron is already allocated. Try to move it to a free carbon.
                try:
                    new_qubit = self.physical_memory.allocate()
                except AllocError:
                    self._logger.error(
                        f"Allocation error. Reason:\n"
                        f"Measuring virtual qubit {virt_id}.\n"
                        f"-> Measuring physical qubit {phys_id}.\n"
                        f"-> Measuring physical qubit with ID > 0 requires "
                        f"physical qubit 0 to be free."
                        f"-> Physical qubit 0 is in use.\n"
                        f"-> Trying to find free physical qubit for qubit 0.\n"
                        f"-> No physical qubits available."
                    )
                yield from self._move_electron_to_carbon(new_qubit)
                elec_app_id, elec_virt_id = self._qnos.get_virt_qubit_for_phys_id(0)
                self._logger.warning(
                    f"moving virtual qubit {elec_virt_id} from app "
                    f"{app_id} from physical ID 0 to {new_qubit}"
                )
                # Update qubit ID mapping.
                self.app_memories[elec_app_id].unmap_virt_id(elec_virt_id)
                self.app_memories[elec_app_id].map_virt_id(elec_virt_id, new_qubit)
                app_mem.unmap_virt_id(virt_id)
                app_mem.map_virt_id(virt_id, 0)
                yield from self._move_carbon_to_electron_for_measure(phys_id)
                self.physical_memory.free(phys_id)
                self.send_signal(SIGNAL_MEMORY_FREED)
                self.qdevice.mem_positions[phys_id].in_use = False
                outcome = yield from self._measure_electron()
                app_mem.set_reg_value(instr.creg, outcome)
            else:
                self.physical_memory.allocate_comm()
                app_mem.unmap_virt_id(virt_id)
                app_mem.map_virt_id(virt_id, 0)
                yield from self._move_carbon_to_electron_for_measure(phys_id)
                self.physical_memory.free(phys_id)
                self.send_signal(SIGNAL_MEMORY_FREED)
                self.qdevice.mem_positions[phys_id].in_use = False
                outcome = yield from self._measure_electron()
                app_mem.set_reg_value(instr.creg, outcome)

        self._logger.debug(
            f"Measuring qubit {virt_id} (physical ID: {phys_id}), "
            f"placing the outcome in register {instr.creg}"
        )

    def _interpret_single_rotation_instr(
        self, app_id: int, instr: nv.RotXInstruction
    ) -> Generator[EventExpression, None, None]:
        if isinstance(instr, nv.RotXInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_X)
        elif isinstance(instr, nv.RotYInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_Y)
        elif isinstance(instr, nv.RotZInstruction):
            yield from self._do_single_rotation(app_id, instr, INSTR_ROT_Z)
        else:
            raise RuntimeError(f"Unsupported instruction {instr}")

    def _interpret_controlled_rotation_instr(
        self, app_id: int, instr: core.ControlledRotationInstruction
    ) -> Generator[EventExpression, None, None]:
        if isinstance(instr, nv.ControlledRotXInstruction):
            yield from self._do_controlled_rotation(app_id, instr, INSTR_CXDIR)
        elif isinstance(instr, nv.ControlledRotYInstruction):
            yield from self._do_controlled_rotation(app_id, instr, INSTR_CYDIR)
        else:
            raise RuntimeError(f"Unsupported instruction {instr}")
