# -*- coding: utf-8 -*-

#TODO: implement commands: oper, mode, topic, names, list, invite
#TODO: '' '' : kick, who, whois, whowas, kill, away
#TODO: '' '' : rehash, restart, wallops,

import logging
from asynchat import async_chat
from datetime import datetime
from re import compile as re_compile
from socket import AF_INET, SOCK_STREAM

LOGFORMAT = '[%(name)s] %(levelname)s - %(message)s'
CTCP_RE = re_compile(r'^\x01(?P<type>[A-Z]+)(?: (?P<data>.+))?\x01$')


class IRCClient(async_chat):
    """
Asynchronous IRC client.
"""
    terminator = '\r\n'
    ctcp_version = None

    def __init__(self, host, port, nickname, username,
                 channels=None,
                 loglevel=logging.INFO,
                 logformat=LOGFORMAT):
        async_chat.__init__(self)
        logging.basicConfig(format=logformat)
        self.host = host
        self.port = port
        self.nickname = nickname
        self.username = username
        self.channels = [] if (channels is None) else channels
        self.received_data = ''
        self.logger = logging.getLogger('%(host)s:%(port)d' % {'host': host, 'port': port})
        self.logger.setLevel(loglevel)
        self.logger.info('connecting to host...')
        self.create_socket(AF_INET, SOCK_STREAM)
        self.connect((host, port))

    def _connection_made(self):
        self.logger.info('connection successful')
        for channel in self.channels:
            self.send_data('JOIN %(chan)s' % {'chan': channel})
        self.on_connection()

    def split_netmask(self, netmask):
        nick = netmask.split('!')[0].lstrip(':')
        user = netmask.split('@')[0].split('!')[1]
        host = netmask.split('@')[1]
        return (nick, user, host)

    def send_data(self, data):
        self.logger.debug('SENT DATA: %(data)s' % {'data': repr(data)})
        data += '\r\n'
        self.push(data)

    def handle_connect(self):
        self.send_data('NICK :%(nick)s' % {'nick': self.nickname})
        self.send_data('USER %(nick)s %(nick)s %(nick)s :%(user)s' % {
            'nick': self.nickname,
            'user': self.username,
        })

    def handle_data(self, data):
        self.logger.debug(str(data))
        token = data.split()
        src = token[0]

        if 'PRIVMSG' in token:
            dst = token[2]
            message = ' '.join(token[3:]).lstrip(':')
            ctcp = CTCP_RE.match(message)
            if ctcp is not None:
                ctcp = ctcp.groupdict()
                self.on_ctcp(src, dst, ctcp)
                return
            self.on_privmsg(src, dst, message)

        elif 'NOTICE' in token:
            dst = token[2]
            message = ' '.join(token[3:]).lstrip(':')
            self.on_notice(src, dst, message)

        elif 'JOIN' in token:
            dst = token[2]
            self.on_join(src, dst)

        elif 'PART' in token:
            dst = token[2]
            message = ' '.join(token[3:]).lstrip(':') if (len(token) > 2) else None
            self.on_part(src, dst, message)

        elif 'PING' in token:
            self.on_ping(token[1])

        elif 376 in token:
            self._connection_made()

        else:
            self.on_unknown_data(data)

    def found_terminator(self):
        self.handle_data(self.received_data)
        self.received_data = ''

    def collect_incoming_data(self, data):
        self.received_data += data

    ##########################
    ## IRC COMMANDS METHODS ##
    ##########################

    def set_nick(self, new_nick):
        self.nickname = new_nick
        self.send_data('NICK %(nick)s' % {'nick': new_nick})

    def privmsg(self, dst, msg, color=None):
        self.send_data('PRIVMSG %(dst)s :%(msg)s' % {
            'dst': dst,
            'msg': msg,
        })

    def notice(self, dst, msg):
        self.send_data('NOTICE %(dst)s :%(msg)s' % {
            'dst': dst,
            'msg': msg,
        })

    def join(self, *dst):
        for channel in dst:
            self.send_data('JOIN %(dst)s' % {'dst': channel})

    def part(self, dst, msg=None):
        data = 'PART %(dst)s' % {'dst': dst}
        if msg is not None:
            data += ' :%(msg)s' % {'msg': msg}
        self.send_data(data)

    def quit(self, msg=None):
        data = 'QUIT'
        if msg is not None:
            data += ' :%(msg)s' % {'msg': msg}
        self.send_data(data)

    def on_ping(self, ping_id):
        self.send_data('PONG %(id)s' % {'id': ping_id})

    def on_ctcp(self, src, dst, ctcp):
        if (ctcp['type'] == 'PING') and (ctcp['data'] is not None):
            self.on_ctcp_ping(src, ctcp)
        elif ctcp['type'] == 'TIME':
            self.on_ctcp_time(src)
        elif ctcp['type'] == 'VERSION':
            self.on_ctcp_version(src)
        elif ctcp['type'] == 'FINGER':
            self.on_ctcp_finger(src)
        elif ctcp['type'] == 'ACTION':
            self.on_action(src, dst, ctcp['data'])

    #####################################################
    ## EVENTS HANDLERS TO (RE-)IMPLEMENT IN A SUBCLASS ##
    #####################################################

    def on_unknown_data(self, data):
        pass

    def on_connection(self):
        pass

    def on_ctcp_ping(self, src, ctcp):
        nick, _, _ = self.split_netmask(src)
        self.notice(nick, '\x01PING %(timestamp)s\x01' % {'timestamp': ctcp['data']})

    def on_ctcp_time(self, src):
        nick, _, _ = self.split_netmask(src)
        message = '%s UTC' % datetime.utcnow()
        self.notice(nick, '\x01TIME :%(time)s' % {'time': message})

    def on_ctcp_version(self, src):
        pass

    def on_ctcp_finger(self, src):
        pass

    def on_action(self, src, dst, msg):
        pass

    def on_privmsg(self, src, dst, msg):
        pass

    def on_notice(self, src, dst, msg):
        pass

    def on_join(self, src, dst):
        pass

    def on_part(self, src, dst, msg):
        pass

    def on_quit(self, src, msg):
        pass

if __name__ == '__main__':
    from asyncore import loop
    host, port = 'irc.plain-text.info', 6667
    nick = username = 'fatbotslim'
    channels = ['#testbot']
    loglevel = logging.DEBUG
    client = IRCClient(host, port, nick, username, channels, loglevel)
    loop()