#! /usr/bin/env avocado-runner-avocado-classless

# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright Red Hat
# Author: David Gibson <david@gibson.dropbear.id.au>

"""
Test A Simple Socket Transport

tasst/exesite.py - Manage simulated network sites for testing
"""


import contextlib

import avocado
from avocado.utils.process import CmdError
from avocado_classless.test import assert_eq, assert_raises, test_output


class Site(contextlib.AbstractContextManager):
    """
    A (usually virtual or simulated) location where we can execute
    commands and configure networks.

    """

    def __init__(self, name):
        self.name = name   # For debugging

    def hostify(self, cmd, **kwargs):
        raise NotImplementedError

    def __enter__(self):
        return self

    def __exit__(self, *exc_details):
        pass

    def output(self, cmd, strip_trail_nl=False, **kwargs):
        kwargs['strip_trail_nl'] = strip_trail_nl
        cmd, kwargs = self.hostify(cmd, **kwargs)
        return avocado.utils.process.system_output(cmd, **kwargs)

    def fg(self, cmd, **kwargs):
        cmd, kwargs = self.hostify(cmd, **kwargs)
        return avocado.utils.process.system(cmd, **kwargs)

    def require_cmds(self, *cmds):
        missing = [c for c in cmds
                   if self.fg(f'type {c}', ignore_status=True) != 0]
        if missing:
            raise avocado.TestCancel(
                f"Missing commands {', '.join(missing)} on {self.name}")


def test_site(sitefn):
    def test_true(s):
        with s as site:
            site.fg('true')

    def test_false(s):
        with s as site:
            assert_raises(CmdError, site.fg, 'false')

    def test_echo(s):
        with s as site:
            msg = 'Hello tasst'
            out = site.output(f'echo {msg}')
            assert_eq(out, msg.encode('utf-8') + b'\n')

    def test_timeout(s):
        with s as site:
            site.fg('sleep infinity', timeout=0.1, ignore_status=True)

    return test_output(test_true, test_false, test_echo, test_timeout)(sitefn)


class RealHost(Site):
    """Represents the host on which the tests are running (as opposed
    to some simulated host created by the tests)

    """

    def __init__(self):
        super().__init__('REAL_HOST')

    def hostify(self, cmd, *, sudo=False, **kwargs):
        assert not sudo, "BUG: Shouldn't run commands with privilege on host"
        return cmd, kwargs


REAL_HOST = RealHost()


@test_site
def real_host():
    return REAL_HOST