import re
import socket
import time
import thread
import Queue

from ssl import wrap_socket, CERT_NONE, CERT_REQUIRED, SSLError


DEFAULT_NAME = 'skybot'
DEFAULT_REALNAME = 'Python bot - http://github.com/rmmh/skybot'
DEFAULT_NICKSERV_NAME = 'nickserv'
DEFAULT_NICKSERV_COMMAND = 'IDENTIFY %s'


def decode(txt):
    for codec in ('utf-8', 'iso-8859-1', 'shift_jis', 'cp1252'):
        try:
            return txt.decode(codec)
        except UnicodeDecodeError:
            continue

    return txt.decode('utf-8', 'ignore')


def censor(text, censored_strings = None):
    text = re.sub("[\n\r]+", " ", text)

    if not censored_strings:
        return text

    words = map(re.escape, censored_strings)
    pattern = "(%s)" % "|".join(words)

    text = re.sub(pattern, "[censored]", text)

    return text


class crlf_tcp(object):

    "Handles tcp connections that consist of utf-8 lines ending with crlf"

    def __init__(self, host, port, timeout=300):
        self.ibuffer = ""
        self.obuffer = ""
        self.oqueue = Queue.Queue()  # lines to be sent out
        self.iqueue = Queue.Queue()  # lines that were received
        self.socket = self.create_socket()
        self.host = host
        self.port = port
        self.timeout = timeout

    def create_socket(self):
        return socket.socket(socket.AF_INET, socket.TCP_NODELAY)

    def run(self):
        while True:
            try:
                self.socket.connect((self.host, self.port))
            except socket.timeout:
                print 'timed out connecting to %s:%s' % (self.host, self.port)
                time.sleep(60)
            else:
                break
        thread.start_new_thread(self.recv_loop, ())
        thread.start_new_thread(self.send_loop, ())

    def recv_from_socket(self, nbytes):
        return self.socket.recv(nbytes)

    def get_timeout_exception_type(self):
        return socket.timeout

    def handle_receive_exception(self, error, last_timestamp):
        if time.time() - last_timestamp > self.timeout:
            self.iqueue.put(StopIteration)
            self.socket.close()
            return True
        return False

    def recv_loop(self):
        last_timestamp = time.time()
        while True:
            try:
                data = self.recv_from_socket(4096)
                self.ibuffer += data
                if data:
                    last_timestamp = time.time()
                else:
                    if time.time() - last_timestamp > self.timeout:
                        self.iqueue.put(StopIteration)
                        self.socket.close()
                        return
                    time.sleep(1)
            except (self.get_timeout_exception_type(), socket.error) as e:
                if self.handle_receive_exception(e, last_timestamp):
                    return
                continue

            while '\r\n' in self.ibuffer:
                line, self.ibuffer = self.ibuffer.split('\r\n', 1)
                self.iqueue.put(decode(line))

    def send_loop(self):
        while True:
            line = self.oqueue.get().splitlines()[0][:500]
            print ">>> %r" % line
            self.obuffer += line.encode('utf-8', 'replace') + '\r\n'
            while self.obuffer:
                sent = self.socket.send(self.obuffer)
                self.obuffer = self.obuffer[sent:]


class crlf_ssl_tcp(crlf_tcp):

    "Handles ssl tcp connetions that consist of utf-8 lines ending with crlf"

    def __init__(self, host, port, ignore_cert_errors, timeout=300):
        self.ignore_cert_errors = ignore_cert_errors
        crlf_tcp.__init__(self, host, port, timeout)

    def create_socket(self):
        return wrap_socket(crlf_tcp.create_socket(self), server_side=False,
                           cert_reqs=CERT_NONE if self.ignore_cert_errors else
                           CERT_REQUIRED)

    def recv_from_socket(self, nbytes):
        return self.socket.read(nbytes)

    def get_timeout_exception_type(self):
        return SSLError

    def handle_receive_exception(self, error, last_timestamp):
        return crlf_tcp.handle_receive_exception(self, error, last_timestamp)

def zip_channels(channels):
    channels.sort(key=lambda x: ' ' not in x)  # keyed channels first
    chans = []
    keys = []
    for channel in channels:
        if ' ' in channel:
            chan, key = channel.split(' ')
            chans.append(chan)
            keys.append(key)
        else:
            chans.append(channel)
    chans = ','.join(chans)
    if keys:
        return [chans, ','.join(keys)]
    else:
        return [chans]

def test_zip_channels():
    assert zip_channels(['#a', '#b c', '#d']) == ['#b,#a,#d', 'c']
    assert zip_channels(['#a', '#b']) == ['#a,#b']

class IRC(object):
    IRC_PREFIX_REM = re.compile(r'(.*?) (.*?) (.*)').match
    IRC_NOPROFEIX_REM = re.compile(r'()(.*?) (.*)').match
    IRC_NETMASK_REM = re.compile(r':?([^!@]*)!?([^@]*)@?(.*)').match
    IRC_PARAM_REF = re.compile(r'(?:^|(?<= ))(:.*|[^ ]+)').findall

    "handles the IRC protocol"
    # see the docs/ folder for more information on the protocol

    def __init__(self, conf):
        self.conn = None

        self.nick = DEFAULT_NAME
        self.user = DEFAULT_NAME
        self.realname = DEFAULT_REALNAME
        self.user_mode = None

        self.server_host = None
        self.server_port = 6667
        self.server_password = None

        self.nickserv_password = None
        self.nickserv_name = DEFAULT_NICKSERV_NAME
        self.nickserv_command = DEFAULT_NICKSERV_COMMAND

        self.channels = []
        self.admins = []
        self.censored_strings = []

        self.out = Queue.Queue()  # responses from the server are placed here
        # format: [rawline, prefix, command, params,
        # nick, user, host, paramlist, msg]

        self.set_conf(conf)

        self.connect()

        thread.start_new_thread(self.parse_loop, ())

    def set_conf(self, conf):
        self.nick = conf.get('nick', DEFAULT_NAME)
        self.user = conf.get('user', DEFAULT_NAME)
        self.realname = conf.get('realname', DEFAULT_REALNAME)
        self.user_mode = conf.get('mode', None)

        self.server_host = conf['server']
        self.server_port = conf.get('port', 6667)
        self.server_password = conf.get('server_password', None)

        self.nickserv_password = conf.get('nickserv_password', None)
        self.nickserv_name = conf.get('nickserv_name', DEFAULT_NICKSERV_NAME)
        self.nickserv_command = conf.get('nickserv_command', DEFAULT_NICKSERV_COMMAND)

        self.channels = conf.get('channels', [])
        self.admins = conf.get('admins', [])
        self.censored_strings = conf.get('censored_strings', [])

        if self.conn is not None:
            self.join_channels()

    def create_connection(self):
        return crlf_tcp(self.server_host, self.server_port)

    def connect(self):
        self.conn = self.create_connection()
        thread.start_new_thread(self.conn.run, ())
        self.cmd("NICK", [self.nick])
        self.cmd("USER", [self.user, "3", "*", self.realname])
        if self.server_password:
            self.cmd("PASS", [self.server_password])

    def parse_loop(self):
        while True:
            msg = self.conn.iqueue.get()

            if msg == StopIteration:
                self.connect()
                continue

            if msg.startswith(":"):  # has a prefix
                prefix, command, params = self.IRC_PREFIX_REM(msg).groups()
            else:
                prefix, command, params = self.IRC_NOPROFEIX_REM(msg).groups()
            nick, user, host = self.IRC_NETMASK_REM(prefix).groups()
            paramlist = self.IRC_PARAM_REF(params)
            lastparam = ""
            if paramlist:
                if paramlist[-1].startswith(':'):
                    paramlist[-1] = paramlist[-1][1:]
                lastparam = paramlist[-1]
            self.out.put([msg, prefix, command, params, nick, user, host,
                          paramlist, lastparam])

            if command == "PING":
                self.cmd("PONG", paramlist)

    def join(self, channel):
        self.cmd("JOIN", channel.split(" "))  # [chan, password]

    def join_channels(self):
        if self.channels:
            # TODO: send multiple join commands for large channel lists
            self.cmd("JOIN", zip_channels(self.channels))

    def msg(self, target, text):
        self.cmd("PRIVMSG", [target, text])

    def cmd(self, command, params=None):
        if params:
            params[-1] = ':' + params[-1]

            params = [censor(p, self.censored_strings) for p in params]

            self.send(command + ' ' + ' '.join(params))
        else:
            self.send(command)

    def send(self, str):
        self.conn.oqueue.put(str)


class FakeIRC(IRC):
    def __init__(self, conf):
        self.set_conf(conf)
        self.out = Queue.Queue()  # responses from the server are placed here

        self.f = open(fn, 'rb')

        thread.start_new_thread(self.parse_loop, ())

    def parse_loop(self):
        while True:
            msg = decode(self.f.readline()[9:])

            if msg == '':
                print "!!!!DONE READING FILE!!!!"
                return

            if msg.startswith(":"):  # has a prefix
                prefix, command, params = irc_prefix_rem(msg).groups()
            else:
                prefix, command, params = irc_noprefix_rem(msg).groups()
            nick, user, host = irc_netmask_rem(prefix).groups()
            paramlist = irc_param_ref(params)
            lastparam = ""
            if paramlist:
                if paramlist[-1].startswith(':'):
                    paramlist[-1] = paramlist[-1][1:]
                lastparam = paramlist[-1]
            self.out.put([msg, prefix, command, params, nick, user, host,
                          paramlist, lastparam])
            if command == "PING":
                self.cmd("PONG", [params])

    def cmd(self, command, params=None):
        pass


class SSLIRC(IRC):
    def __init__(self, conf):
        super(SSLIRC, self).__init__(conf=conf)

        self.server_port = 6697
        self.server_ignore_cert = False

    def set_conf(self, conf):
        super(SSLIRC, self).set_conf(conf)

        self.server_port = conf.get('port', 6697)
        self.server_ignore_cert = conf.get('ignore_cert', False)

    def create_connection(self):
        return crlf_ssl_tcp(self.server_host, self.server_port, self.server_ignore_cert)