from __future__ import annotations

from pathlib import Path
from subprocess import Popen, call, check_output, PIPE

from zfs_backup.misc import assert_type


class CommandInterface:
    _BINARY: Path

    @classmethod
    def _run_command(cls, *args: str) -> None:
        CommandRunner.run([str(cls._BINARY), *args])

    @classmethod
    def _get_output(cls, *args: str) -> str:
        return CommandRunner.get_output([str(cls._BINARY), *args])

    @classmethod
    def _open_stream(cls, *args: str) -> Popen:
        return CommandRunner.send_stream([str(cls._BINARY), *args])

    @classmethod
    def _receive_stream(cls, *args: str, stream: Popen) -> None:
        CommandRunner.receive_from_stream([str(cls._BINARY), *args], stream=stream)


class CommandRunner:
    @staticmethod
    def _sanity_check(cmdline: list[str]) -> None:
        assert_type(cmdline, list, "Command line must be a list")
        for item in cmdline:
            assert_type(item, str, "Only strings allowed in command line")

    @staticmethod
    def _to_list(command: str | list[str]) -> list[str]:
        """If the command is a str, return it as list. Otherwise, return the command."""
        if isinstance(command, str):
            return [command]
        return command

    @classmethod
    def run(cls, cmdline: str | list[str]) -> None:
        """Run the command, wait for it to return."""
        cmdline = cls._to_list(cmdline)
        cls._sanity_check(cmdline)
        call(cmdline)

    @classmethod
    def get_output(cls, cmdline: str | list[str]) -> str:
        """Run the command, return the output of the command."""
        cmdline = cls._to_list(cmdline)
        cls._sanity_check(cmdline)
        return check_output(cmdline).strip().decode()

    @classmethod
    def receive_from_stream(cls, cmdline: str | list[str], stream: Popen) -> None:
        """Run the command, receive data from a pipe to stdin."""
        cmdline = cls._to_list(cmdline)
        cls._sanity_check(cmdline)
        check_output(cmdline, stdin=stream.stdout)

    @classmethod
    def send_stream(cls, cmdline: str | list[str]) -> Popen:
        """Run the command, redirect stdout to a pipe."""
        cmdline = cls._to_list(cmdline)
        cls._sanity_check(cmdline)
        return Popen(cmdline, stdout=PIPE)