from collections.abc import Callable
from types import ModuleType

from ..messages import BaseMessage
from ..ports import BaseInput, BaseIOPort, BaseOutput, IOPort

DEFAULT_BACKEND: str = "mido.backends.rtmidi"

class Backend:
    """
    Wrapper for backend module.

    A backend module implements classes for input and output ports for
    a specific MIDI library. The Backend object wraps around the
    object and provides convenient 'open_*()' and 'get_*_names()'
    functions.
    """

    name: str
    api: str | None
    use_environ: bool
    def __init__(
        self, name: str | None = ..., api: str | None = ..., load: bool = False, use_environ: bool = True
    ) -> None: ...
    @property
    def module(self) -> ModuleType:
        """A reference module implementing the backend.

        This will always be a valid reference to a module. Accessing
        this property will load the module. Use .loaded to check if
        the module is loaded.
        """

    @property
    def loaded(self) -> bool:
        """Return True if the module is loaded."""

    def load(self) -> None:
        """Load the module.

        Does nothing if the module is already loaded.

        This function will be called if you access the 'module'
        property."""

    def open_input(
        self,
        name: str | None = ...,
        virtual: bool = False,
        callback: Callable[[BaseMessage], object] | None = ...,
        **kwargs: object,
    ) -> BaseInput:
        """Open an input port.

        If the environment variable MIDO_DEFAULT_INPUT is set,
        it will override the default port.

        virtual=False
          Passing True opens a new port that other applications can
          connect to. Raises IOError if not supported by the backend.

        callback=None
          A callback function to be called when a new message arrives.
          The function should take one argument (the message).
          Raises IOError if not supported by the backend.
        """

    def open_output(
        self, name: str | None = ..., virtual: bool = False, autoreset: bool = False, **kwargs: object
    ) -> BaseOutput:
        """Open an output port.

        If the environment variable MIDO_DEFAULT_OUTPUT is set,
        it will override the default port.

        virtual=False
          Passing True opens a new port that other applications can
          connect to. Raises IOError if not supported by the backend.

        autoreset=False
          Automatically send all_notes_off and reset_all_controllers
          on all channels. This is the same as calling `port.reset()`.
        """

    def open_ioport[TIn: BaseInput = BaseInput, TOut: BaseOutput = BaseOutput](
        self,
        name: str | None = ...,
        virtual: bool = False,
        callback: Callable[[BaseMessage], object] | None = ...,
        autoreset: bool = False,
        **kwargs: object,
    ) -> BaseIOPort | IOPort[TIn, TOut]:
        """Open a port for input and output.

        If the environment variable MIDO_DEFAULT_IOPORT is set,
        it will override the default port.

        virtual=False
          Passing True opens a new port that other applications can
          connect to. Raises IOError if not supported by the backend.

        callback=None
          A callback function to be called when a new message arrives.
          The function should take one argument (the message).
          Raises IOError if not supported by the backend.

        autoreset=False
          Automatically send all_notes_off and reset_all_controllers
          on all channels. This is the same as calling `port.reset()`.
        """

    def get_input_names(self, **kwargs: object) -> list[str]:
        """Return a list of all input port names."""

    def get_output_names(self, **kwargs: object) -> list[str]:
        """Return a list of all output port names."""

    def get_ioport_names(self, **kwargs: object) -> list[str]:
        """Return a list of all I/O port names."""