#! /usr/bin/python3

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

"""
Test A Simple Socket Transport

pasta.py - Helpers for starting pasta
"""

import contextlib
import os.path
import tempfile


PASTA_BIN = './pasta'


class Pasta(contextlib.AbstractContextManager):
    """A managed pasta instance"""

    def __init__(self, *, host, ns, opts):
        self.host = host
        self.ns = ns
        self.opts = opts
        self.proc = None

    def __enter__(self):
        self.tmpdir = tempfile.TemporaryDirectory()
        piddir = self.tmpdir.__enter__()
        pidfile = os.path.join(piddir, 'pasta.pid')
        relpid = self.ns.relative_pid(self.host)
        cmd = [f'{PASTA_BIN}', '-f', '-P', f'{pidfile}'] + list(self.opts) + \
            [f'{relpid}']
        self.proc = self.host.bg(*cmd)
        self.proc.__enter__()
        # Wait for the PID file to be written
        pidstr = None
        while not pidstr:
            pidstr = self.host.output('cat', f'{pidfile}', check=False)
        self.pid = int(pidstr)
        return self

    def __exit__(self, *exc_details):
        try:
            self.host.fg('kill', '-TERM', f'{self.pid}')
            self.proc.__exit__(*exc_details)
        finally:
            self.tmpdir.__exit__(*exc_details)