## Copyright 2010, 2011, 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>.
##
## This file is part of Hop.
##
## Hop 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 3 of the License, or
## (at your option) any later version.
##
## Hop 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 Hop.  If not, see <http://www.gnu.org/licenses/>.

import threading
import socket

import namespace
import sexp
from dispatch import HopRelayMixin

class HopRelay(HopRelayMixin):
    def __init__(self, in_ch, out_ch, ns = None, peer_address = None):
        self.in_ch = in_ch
        self.out_ch = out_ch
        self.peer_address = peer_address
        self.thread = threading.Thread(target = self.relay_main)
        self.namespace = ns if ns else namespace.default_namespace
        self.lock = threading.Lock()
        self.thread.start()

    def write(self, x):
        try:
            self.lock.acquire()
            sexp.write_sexp(self.out_ch, x)
            self.out_ch.flush()
        finally:
            self.lock.release()

    def error(self, message, details):
        self.write(['error', message, details])

    def handle_hop(self, msg):
        self.write(msg)

    def inbound_hop_post(self, name, body, token):
        self.namespace.send(name, body)

    def inbound_hop_subscribe(self, filter, sink, name, replysink, replyname):
        if self.namespace.bind(filter, self):
            self.namespace.post(replysink, replyname, ['subscribe-ok', filter], '')

    def inbound_hop_unsubscribe(self, token):
        self.namespace.unbind(token)

    def relay_main(self):
        self.write(['subscribe', self.namespace.nodename, '', '', '', ''])
        try:
            while True:
                try:
                    m = sexp.read_sexp(self.in_ch)
                except sexp.SyntaxError, e:
                    self.error('Syntax error', ["http://people.csail.mit.edu/rivest/Sexp.txt"])
                    return
                self.inbound_hop(m)
        except EOFError:
            pass
        finally:
            self.in_ch.close()
            self.out_ch.close()

class TcpRelayServer:
    def __init__(self, host = '0.0.0.0', port = 5671):
        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.server_socket.bind((host, port))
        self.server_socket.listen(4)
        self.thread = threading.Thread(target = self.listen_main)
        self.thread.start()

    def listen_main(self):
        while True:
            conn, addr = self.server_socket.accept()
            conn.send(sexp.format(['hop']))
            HopRelay(conn.makefile(mode = 'r'), conn.makefile(mode = 'w'), peer_address = addr)