"""
opercmds.py: Provides a subset of network management commands.
"""
import argparse

from pylinkirc import utils
from pylinkirc.log import log
from pylinkirc.coremods import permissions

# Having a hard limit here is sensible because otherwise it can flood the client or server off.
CHECKBAN_MAX_RESULTS = 200

def _checkban_positiveint(value):
    value = int(value)
    if value <= 0 or value > CHECKBAN_MAX_RESULTS:
         raise argparse.ArgumentTypeError("%s is not a positive integer between 1 and %s." % (value, CHECKBAN_MAX_RESULTS))
    return value

checkban_parser = utils.IRCParser()
checkban_parser.add_argument('banmask')
checkban_parser.add_argument('target', nargs='?', default='')
checkban_parser.add_argument('--channel', default='')
checkban_parser.add_argument('--maxresults', type=_checkban_positiveint, default=50)

def checkban(irc, source, args, use_regex=False):
    """<banmask> [<target nick or hostmask>] [--channel #channel] [--maxresults <num>]

    CHECKBAN provides a ban checker command based on nick!user@host masks, user@host masks, and
    PyLink extended targets.

    If a target nick or hostmask is given, this command returns whether the given banmask will match it.
    Otherwise, it will display a list of connected users matching the banmask.

    If the --channel argument is given without a target mask, the returned results will only
    include users in the given channel.

    The --maxresults option configures how many responses will be shown."""
    permissions.check_permissions(irc, source, ['opercmds.checkban'])

    args = checkban_parser.parse_args(args)
    if not args.target:
        # No hostmask was given, return a list of matched users.
        results = 0

        userlist_func = irc.match_all_re if use_regex else irc.match_all
        irc.reply("Checking for hosts that match \x02%s\x02:" % args.banmask, private=True)
        for uid in userlist_func(args.banmask, channel=args.channel):
            if results < args.maxresults:
                userobj = irc.users[uid]
                s = "\x02%s\x02 (%s@%s) [%s] {\x02%s\x02}" % (userobj.nick, userobj.ident,
                    userobj.host, userobj.realname, irc.get_friendly_name(irc.get_server(uid)))

                # Always reply in private to prevent information leaks.
                irc.reply(s, private=True)
            results += 1
        else:
            if results:
                irc.reply("\x02%s\x02 out of \x02%s\x02 results shown." %
                          (min([results, args.maxresults]), results), private=True)
            else:
                irc.reply("No results found.", private=True)
    else:
        # Target can be both a nick (of an online user) or a hostmask. irc.match_host() handles this
        # automatically.
        if irc.match_host(args.banmask, args.target):
            irc.reply('Yes, \x02%s\x02 matches \x02%s\x02.' % (args.target, args.banmask))
        else:
            irc.reply('No, \x02%s\x02 does not match \x02%s\x02.' % (args.target, args.banmask))
utils.add_cmd(checkban, aliases=('cban',))

def checkbanre(irc, source, args):
    """<regular expression> [<target nick or hostmask>] [--channel #channel] [--maxresults <num>]

    CHECKBANRE provides a ban checker command based on regular expressions matched against
    users' "nick!user@host [gecos]" mask.

    If a target nick or hostmask is given, this command returns whether the given banmask will match it.
    Otherwise, it will display a list of connected users matching the banmask.

    If the --channel argument is given without a target mask, the returned results will only
    include users in the given channel.

    The --maxresults option configures how many responses will be shown."""
    permissions.check_permissions(irc, source, ['opercmds.checkban.re'])
    return checkban(irc, source, args, use_regex=True)

utils.add_cmd(checkbanre, aliases=('crban',))

massban_parser = utils.IRCParser()
massban_parser.add_argument('channel')
massban_parser.add_argument('banmask')
# Regarding default ban reason: it's a good idea not to leave in the caller to prevent retaliation...
massban_parser.add_argument('reason', nargs='*', default="Banned")
massban_parser.add_argument('--quiet', '-q', action='store_true')

def massban(irc, source, args, use_regex=False):
    """<channel> <banmask / exttarget> [<kick reason>] [--quiet/-q]

    Applies (i.e. kicks affected users) the given PyLink banmask on the specified channel.

    The --quiet option can also be given to mass-mute the given user on networks where this is supported
    (currently ts6, unreal, and inspircd). No kicks will be sent in this case."""
    permissions.check_permissions(irc, source, ['opercmds.massban'])

    args = massban_parser.parse_args(args)

    if args.channel not in irc.channels:
        irc.error("Unknown channel %r" % args.channel)
        return

    results = 0

    userlist_func = irc.match_all_re if use_regex else irc.match_all
    for uid in userlist_func(args.banmask, channel=args.channel):
        # Remove the target's access before banning them.
        bans = [('-%s' % irc.cmodes[prefix], uid) for prefix in irc.channels[args.channel].get_prefix_modes(uid) if prefix in irc.cmodes]

        # Then, add the actual ban.
        bans += [irc.make_channel_ban(uid, ban_type='quiet' if args.quiet else 'ban')]
        irc.mode(irc.pseudoclient.uid, args.channel, bans)

        try:
            irc.call_hooks([irc.pseudoclient.uid, 'OPERCMDS_MASSBAN',
                            {'target': args.channel, 'modes': bans, 'parse_as': 'MODE'}])
        except:
            log.exception('(%s) Failed to send process massban hook; some bans may have not '
                          'been sent to plugins / relay networks!', irc.name)

        if not args.quiet:
            irc.kick(irc.pseudoclient.uid, args.channel, uid, args.reason)

            # XXX: this better not be blocking...
            try:
                irc.call_hooks([irc.pseudoclient.uid, 'OPERCMDS_MASSKICK',
                                {'channel': args.channel, 'target': uid, 'text': args.reason, 'parse_as': 'KICK'}])

            except:
                log.exception('(%s) Failed to send process massban hook; some kicks may have not '
                              'been sent to plugins / relay networks!', irc.name)

        results += 1
    else:
        irc.reply('Banned %s users on %r.' % (results, args.channel))
utils.add_cmd(massban, aliases=('mban',))

def massbanre(irc, source, args):
    """<channel> <regular expression> [<kick reason>] [--quiet/-q]

    Bans users on the specified channel whose "nick!user@host [gecos]" mask matches the given Python-style regular expression.
    (https://docs.python.org/3/library/re.html#regular-expression-syntax describes supported syntax)

    The --quiet option can also be given to mass-mute the given user on networks where this is supported
    (currently ts6, unreal, and inspircd). No kicks will be sent in this case.

    \x02Be careful when using this command, as it is easy to make mistakes with regex. Use 'checkbanre'
    to check your bans first!\x02

    """
    permissions.check_permissions(irc, source, ['opercmds.massban.re'])
    return massban(irc, source, args, use_regex=True)

utils.add_cmd(massbanre, aliases=('rban',))

@utils.add_cmd
def jupe(irc, source, args):
    """<server> [<reason>]

    Jupes the given server."""

    permissions.check_permissions(irc, source, ['opercmds.jupe'])

    try:
        servername = args[0]
        reason = ' '.join(args[1:]) or "No reason given"
        desc = "Juped by %s: [%s]" % (irc.get_hostmask(source), reason)
    except IndexError:
        irc.error('Not enough arguments. Needs 1-2: servername, reason (optional).')
        return

    if not utils.isServerName(servername):
        irc.error("Invalid server name %r." % servername)
        return

    sid = irc.spawn_server(servername, desc=desc)

    irc.call_hooks([irc.pseudoclient.uid, 'OPERCMDS_SPAWNSERVER',
                   {'name': servername, 'sid': sid, 'text': desc}])

    irc.reply("Done.")


@utils.add_cmd
def kick(irc, source, args):
    """<channel> <user> [<reason>]

    Kicks <user> from the specified channel."""
    permissions.check_permissions(irc, source, ['opercmds.kick'])
    try:
        channel = irc.to_lower(args[0])
        target = args[1]
        reason = ' '.join(args[2:])
    except IndexError:
        irc.error("Not enough arguments. Needs 2-3: channel, target, reason (optional).")
        return

    targetu = irc.nick_to_uid(target)

    if channel not in irc.channels:  # KICK only works on channels that exist.
        irc.error("Unknown channel %r." % channel)
        return

    if not targetu:
        # Whatever we were told to kick doesn't exist!
        irc.error("No such target nick %r." % target)
        return

    sender = irc.pseudoclient.uid
    irc.kick(sender, channel, targetu, reason)
    irc.reply("Done.")
    irc.call_hooks([sender, 'OPERCMDS_KICK', {'channel': channel, 'target': targetu,
                                              'text': reason, 'parse_as': 'KICK'}])

@utils.add_cmd
def kill(irc, source, args):
    """<target> [<reason>]

    Kills the given target."""
    permissions.check_permissions(irc, source, ['opercmds.kill'])
    try:
        target = args[0]
        reason = ' '.join(args[1:])
    except IndexError:
        irc.error("Not enough arguments. Needs 1-2: target, reason (optional).")
        return

    # Convert the source and target nicks to UIDs.
    sender = irc.pseudoclient.uid
    targetu = irc.nick_to_uid(target)
    userdata = irc.users.get(targetu)

    if targetu not in irc.users:
        # Whatever we were told to kick doesn't exist!
        irc.error("No such nick %r." % target)
        return

    irc.kill(sender, targetu, reason)

    # Format the kill reason properly in hooks.
    reason = "Killed (%s (%s))" % (irc.get_friendly_name(sender), reason)

    irc.reply("Done.")
    irc.call_hooks([sender, 'OPERCMDS_KILL', {'target': targetu, 'text': reason,
                                              'userdata': userdata, 'parse_as': 'KILL'}])

@utils.add_cmd
def mode(irc, source, args):
    """<channel> <modes>

    Sets the given modes on the target channel."""

    permissions.check_permissions(irc, source, ['opercmds.mode'])

    try:
        target, modes = args[0], args[1:]
    except IndexError:
        irc.error('Not enough arguments. Needs 2: target, modes to set.')
        return

    if target not in irc.channels:
        irc.error("Unknown channel %r." % target)
        return
    elif not modes:
        # No modes were given before parsing (i.e. mode list was blank).
        irc.error("No valid modes were given.")
        return

    parsedmodes = irc.parse_modes(target, modes)

    if not parsedmodes:
        # Modes were given but they failed to parse into anything meaningful.
        # For example, "mode #somechan +o" would be erroneous because +o
        # requires an argument!
        irc.error("No valid modes were given.")
        return

    irc.mode(irc.pseudoclient.uid, target, parsedmodes)

    # Call the appropriate hooks for plugins like relay.
    irc.call_hooks([irc.pseudoclient.uid, 'OPERCMDS_MODE',
                   {'target': target, 'modes': parsedmodes, 'parse_as': 'MODE'}])

    irc.reply("Done.")

@utils.add_cmd
def topic(irc, source, args):
    """<channel> <topic>

    Changes the topic in a channel."""
    permissions.check_permissions(irc, source, ['opercmds.topic'])
    try:
        channel = args[0]
        topic = ' '.join(args[1:])
    except IndexError:
        irc.error("Not enough arguments. Needs 2: channel, topic.")
        return

    if channel not in irc.channels:
        irc.error("Unknown channel %r." % channel)
        return

    irc.topic(irc.pseudoclient.uid, channel, topic)

    irc.reply("Done.")
    irc.call_hooks([irc.pseudoclient.uid, 'OPERCMDS_TOPIC',
                   {'channel': channel, 'text': topic, 'setter': source,
                    'parse_as': 'TOPIC'}])

@utils.add_cmd
def chghost(irc, source, args):
    """<user> <new host>

    Changes the visible host of the target user."""
    chgfield(irc, source, args, 'host')

@utils.add_cmd
def chgident(irc, source, args):
    """<user> <new ident>

    Changes the ident of the target user."""
    chgfield(irc, source, args, 'ident')

@utils.add_cmd
def chgname(irc, source, args):
    """<user> <new name>

    Changes the GECOS (realname) of the target user."""
    chgfield(irc, source, args, 'name', 'GECOS')

def chgfield(irc, source, args, human_field, internal_field=None):
    permissions.check_permissions(irc, source, ['opercmds.chg' + human_field])
    try:
        target = args[0]
        new = args[1]
    except IndexError:
        irc.error("Not enough arguments. Needs 2: target, new %s." % human_field)
        return

    # Find the user
    targetu = irc.nick_to_uid(target)
    if targetu not in irc.users:
        irc.error("No such nick %r." % target)
        return

    internal_field = internal_field or human_field.upper()
    irc.update_client(targetu, internal_field, new)
    irc.reply("Done.")