# 2ping - A bi-directional ping utility
# Copyright (C) 2010-2020 Ryan Finnie
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.

import argparse
import os
import socket
import sys

from . import __version__
from .utils import _, AES


def parse_args(argv=None):
    if argv is None:
        argv = sys.argv

    if argv[0].endswith("2ping6"):
        ipv6_default = True
    else:
        ipv6_default = False

    parser = argparse.ArgumentParser(
        description="2ping ({})".format(__version__),
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
        prog=os.path.basename(argv[0]),
    )
    parser.add_argument(
        "--version",
        "-V",
        action="version",
        version=__version__,
        help=_("report the program version"),
    )

    # Positionals
    parser.add_argument(
        "host", type=str, default=None, nargs="*", help=_("host to ping")
    )

    # ping-compatible options
    parser.add_argument(
        "--audible", "-a", dest="audible", action="store_true", help=_("audible ping")
    )
    parser.add_argument(
        "--adaptive",
        "-A",
        dest="adaptive",
        action="store_true",
        help=_("adaptive RTT ping"),
    )
    parser.add_argument(
        "--count", "-c", dest="count", type=int, help=_("number of pings to send")
    )
    parser.add_argument(
        "--flood", "-f", dest="flood", action="store_true", help=_("flood mode")
    )
    parser.add_argument(
        "--interval",
        "-i",
        dest="interval",
        type=float,
        default=1.0,
        help=_("seconds between pings"),
        metavar="SECONDS",
    )
    parser.add_argument(
        "--interface-address",
        "-I",
        dest="interface_address",
        type=str,
        action="append",
        default=[],
        help=_("interface bind address"),
        metavar="ADDRESS",
    )
    parser.add_argument(
        "--preload",
        "-l",
        dest="preload",
        type=int,
        default=1,
        help=_("number of pings to send at start"),
        metavar="COUNT",
    )
    parser.add_argument(
        "--pattern",
        "-p",
        dest="pattern",
        type=str,
        help=_("hex pattern for padding"),
        metavar="HEX_BYTES",
    )
    parser.add_argument(
        "--quiet", "-q", dest="quiet", action="store_true", help=_("quiet mode")
    )
    parser.add_argument(
        "--packetsize-compat",
        "-s",
        dest="packetsize_compat",
        type=int,
        help=_("packet size (ping compatible)"),
        metavar="BYTES",
    )
    parser.add_argument(
        "--verbose", "-v", dest="verbose", action="store_true", help=_("verbose mode")
    )
    parser.add_argument(
        "--deadline",
        "-w",
        dest="deadline",
        type=float,
        help=_("maximum run time"),
        metavar="SECONDS",
    )

    # 2ping options
    parser.add_argument("--all-interfaces", action="store_true", help=_("deprecated"))
    parser.add_argument(
        "--auth", type=str, help=_("HMAC authentication key"), metavar="KEY"
    )
    parser.add_argument(
        "--auth-digest",
        type=str,
        default="hmac-md5",
        choices=["hmac-md5", "hmac-sha1", "hmac-sha256", "hmac-crc32", "hmac-sha512"],
        help=_("HMAC authentication digest"),
        metavar="DIGEST",
    )
    parser.add_argument("--debug", action="store_true", help=_("debug mode"))
    parser.add_argument("--encrypt", type=str, help=_("Encryption key"), metavar="KEY")
    parser.add_argument(
        "--encrypt-method",
        type=str,
        default="hkdf-aes256-cbc",
        choices=["hkdf-aes256-cbc"],
        help=_("Encryption method"),
        metavar="METHOD",
    )
    parser.add_argument(
        "--fuzz", type=float, help=_("incoming fuzz percentage"), metavar="PERCENT"
    )
    parser.add_argument(
        "--inquire-wait",
        type=float,
        default=10.0,
        help=_("maximum time before loss inquiries"),
        metavar="SECONDS",
    )
    parser.add_argument("--ipv4", "-4", action="store_true", help=_("force IPv4"))
    parser.add_argument(
        "--ipv6", "-6", action="store_true", default=ipv6_default, help=_("force IPv6")
    )
    parser.add_argument("--listen", action="store_true", help=_("listen mode"))
    parser.add_argument(
        "--loopback", action="store_true", help=_("UNIX loopback test mode")
    )
    parser.add_argument(
        "--loopback-pairs",
        type=int,
        default=1,
        help=_("number of loopback pairs to create"),
        metavar="PAIRS",
    )
    parser.add_argument(
        "--max-packet-size",
        type=int,
        default=512,
        help=_("maximum packet size"),
        metavar="BYTES",
    )
    parser.add_argument(
        "--min-packet-size",
        type=int,
        default=128,
        help=_("minimum packet size"),
        metavar="BYTES",
    )
    parser.add_argument(
        "--nagios",
        type=str,
        help=_("nagios-compatible output"),
        metavar="WRTA,WLOSS%,CRTA,CLOSS%",
    )
    parser.add_argument(
        "--no-3way", action="store_true", help=_("do not send 3-way pings")
    )
    parser.add_argument(
        "--no-match-packet-size",
        action="store_true",
        help=_("do not match packet size of peer"),
    )
    parser.add_argument(
        "--no-send-version",
        action="store_true",
        help=_("do not send program version to peers"),
    )
    parser.add_argument(
        "--notice", type=str, help=_("arbitrary notice text"), metavar="TEXT"
    )
    parser.add_argument(
        "--packet-loss",
        type=str,
        help=_("percentage simulated packet loss"),
        metavar="OUT:IN",
    )
    parser.add_argument(
        "--port", type=str, default="15998", help=_("port to connect / bind to")
    )
    parser.add_argument(
        "--send-monotonic-clock",
        action="store_true",
        help=_("send monotonic clock to peers"),
    )
    parser.add_argument(
        "--send-random", type=int, help=_("send random data to peers"), metavar="BYTES"
    )
    parser.add_argument(
        "--send-time", action="store_true", help=_("send wall clock time to peers")
    )
    parser.add_argument(
        "--stats", type=float, help=_("print recurring statistics"), metavar="SECONDS"
    )
    parser.add_argument(
        "--srv", action="store_true", help=_("lookup SRV records in client mode")
    )
    parser.add_argument(
        "--srv-service",
        type=str,
        default="2ping",
        help=_("service name for SRV lookups"),
    )
    parser.add_argument(
        "--subtract-peer-host-latency",
        action="store_true",
        help=_("subtract peer host latency from RTT calculations, if sent"),
    )

    # ping-compatible ignored options
    for opt in "b|B|d|L|n|R|r|U".split("|"):
        parser.add_argument(
            "-{}".format(opt),
            action="store_true",
            dest="ignored_{}".format(opt),
            help=argparse.SUPPRESS,
        )
    for opt in "F|Q|S|t|T|M|W".split("|"):
        parser.add_argument(
            "-{}".format(opt),
            type=str,
            default=None,
            dest="ignored_{}".format(opt),
            help=argparse.SUPPRESS,
        )

    args = parser.parse_args(args=argv[1:])

    if (not args.listen) and (not args.host) and (not args.loopback):
        parser.print_help()
        parser.exit()
    if args.loopback and not hasattr(socket, "AF_UNIX"):
        parser.error("--loopback not supported on non-UNIX platforms")
    if args.nagios:
        args.quiet = True
        if (not args.count) and (not args.deadline):
            args.count = 5
        nagios_opts = args.nagios.split(",")
        if len(nagios_opts) != 4:
            parser.error(_("Invalid limits"))
        (
            args.nagios_warn_rta,
            args.nagios_warn_loss,
            args.nagios_crit_rta,
            args.nagios_crit_loss,
        ) = nagios_opts
        if args.nagios_warn_loss[-1:] != "%":
            parser.error(_("Invalid limits"))
        if args.nagios_crit_loss[-1:] != "%":
            parser.error(_("Invalid limits"))
        try:
            args.nagios_warn_loss = float(args.nagios_warn_loss[:-1])
            args.nagios_crit_loss = float(args.nagios_crit_loss[:-1])
            args.nagios_warn_rta = float(args.nagios_warn_rta)
            args.nagios_crit_rta = float(args.nagios_crit_rta)
        except ValueError as e:
            parser.error(e.message)
    if args.packetsize_compat:
        args.min_packet_size = args.packetsize_compat + 8
    if args.max_packet_size < args.min_packet_size:
        parser.error(_("Maximum packet size must be at least minimum packet size"))
    if args.max_packet_size < 64:
        parser.error(_("Maximum packet size must be at least 64"))
    args.packet_loss_in = 0
    args.packet_loss_out = 0
    if args.packet_loss:
        if ":" in args.packet_loss:
            (v_out, v_in) = args.packet_loss.split(":", 1)
            try:
                args.packet_loss_out = float(v_out)
                args.packet_loss_in = float(v_in)
            except ValueError as e:
                parser.error(e.message)
        else:
            try:
                args.packet_loss_in = args.packet_loss_out = float(args.packet_loss)
            except ValueError as e:
                parser.error(_("Packet loss: {error}").format(error=e.message))
    if args.pattern:
        if len(args.pattern) & 1:
            parser.error(_("Pattern must be full bytes"))
        if len(args.pattern) > 32:
            parser.error(_("Pattern must be 16 bytes or less"))
        args.pattern_bytes = b""
        for i in range(int(len(args.pattern) / 2)):
            a = args.pattern[(i * 2) : (i * 2 + 2)]
            try:
                b = int(a, 16)
            except ValueError as e:
                parser.error(_("Pattern: {error}").format(error=e.message))
            args.pattern_bytes += bytes([b])
    else:
        args.pattern_bytes = b"\x00"

    hmac_id_map = {
        "hmac-md5": 1,
        "hmac-sha1": 2,
        "hmac-sha256": 3,
        "hmac-crc32": 4,
        "hmac-sha512": 5,
    }
    args.auth_digest_index = hmac_id_map[args.auth_digest]

    if args.encrypt and isinstance(AES, ImportError):
        parser.error(_("Crypto module required for encryption"))

    encrypt_id_map = {"hkdf-aes256-cbc": 1}
    args.encrypt_method_index = encrypt_id_map[args.encrypt_method]

    if args.debug:
        args.verbose = True

    return args