"""Representation of Apple II + player virtual machine state."""

from typing import Iterator

import numpy as np

import screen


class Machine:
    """Represents Apple II and player virtual machine state."""

    def __init__(
            self,
            memmap: screen.MemoryMap,
            update_priority: np.array
    ):
        self.page = 0x20  # type: int
        self.content = 0x7f  # type: int

        self.memmap = memmap  # type: screen.MemoryMap
        self.update_priority = update_priority  # type: np.array

    def emit(self, opcode: "Opcode") -> Iterator[int]:
        """

        :param opcode:
        :return:
        """
        cmd = opcode.emit_command(opcode)
        if cmd:
            yield from cmd
        data = opcode.emit_data()
        if data:
            yield from data

        # Update changes in memory map, if any
        opcode.apply(self)