"""
Contributors can be viewed at:
http://svn.secondlife.com/svn/linden/projects/2008/pyogp/lib/base/trunk/CONTRIBUTORS.txt 

$LicenseInfo:firstyear=2008&license=apachev2$

Copyright 2009, Linden Research, Inc.

Licensed under the Apache License, Version 2.0.
You may obtain a copy of the License at:
    http://www.apache.org/licenses/LICENSE-2.0
or in 
    http://svn.secondlife.com/svn/linden/projects/2008/pyogp/lib/base/LICENSE.txt

$/LicenseInfo$
"""

from msgtypes import PackFlags

class Host(object):

    def __init__(self, context):
        self.ip = context[0]
        self.port = context[1]

    def __repr__(self):                                                              
        """return a string representation"""
        return str("Host is '%s:%s'" %(self.ip, self.port))

    def is_ok(self):
        if self.ip == None or self.port == None or \
           self.ip == 0 or self.port == 0:
            return False

        return True

    def set_host_by_name(self, hostname):
        pass

class Circuit(object):
    """ This is used to keep track of a given circuit. It keeps statistics
        as well as circuit information. """
    """ Some statistics things we may need: bytes/packets in, bytes/packets out,
        unacked packet count/bytes, acked packet count/bytes"""

    def __init__(self, host, pack_in_id):
        self.host = host
        self.circuit_code = 0
        self.session_id = 0
        self.is_alive = True
        self.is_trusted = False
        self.is_blocked = False
        self.allow_timeout = True
        self.last_packet_out_id  = 0  #id of the packet we last sent
        self.last_packet_in_id   = pack_in_id

        self.acks                = [] #packets we need to ack (ids)       
        self.unacked_packets     = {} #packets we want acked, can be resent
        self.unack_packet_count  = 0
        self.unack_packet_bytes  = 0
        self.final_retry_packets = {} #packets we want acked, can't be resent
        self.final_packet_count  = 0

    def next_packet_id(self):
        self.last_packet_out_id += 1
        return self.last_packet_out_id

    def prepare_packet(self, packet, flag=PackFlags.LL_NONE, retries=0):
        packet.send_flags = flag
        packet.retries = retries

        packet.packet_id = self.next_packet_id()

        #if we have acks that we can add on, add them
        ack_count = len(self.acks)
        if ack_count > 0 and packet.name != "PacketAck":
            packet.send_flags |= PackFlags.LL_ACK_FLAG

            #also, sends as many acks as we can onto the end of the packet
            #acks are just the packet_id that we are acking
            for packet_id in self.acks:
                packet.add_ack(packet_id)

        if flag == PackFlags.LL_RELIABLE_FLAG:
            self.add_reliable_packet(packet)

    def handle_packet(self, packet):
        #if its a reliable packet, get all acks from packet, set them to be acked
        for ack_packet_id in packet.acks:
            self.ack_reliable_packet(ack_packet_id)

        if packet.reliable == True:
            self.collect_ack(packet.packet_id)

    def ack_reliable_packet(self, packet_id):
        #go through the packets waiting to be acked, and set them as acked
        if packet_id in self.unacked_packets:
            del self.unacked_packets[packet_id]
            self.unack_packet_count -= 1

        if packet_id in self.final_retry_packets:
            del self.final_retry_packets[packet_id]
            self.final_packet_count -= 1

    def collect_ack(self, packet_id):
        """ set a packet_id that this circuit needs to eventually ack
            (need to send ack out)"""
        self.acks.append(packet_id)

    def add_reliable_packet(self, packet):
        """ add a packet that we want to be acked
            (want an incoming ack) """
        self.unack_packet_count += 1
        #self.unack_packet_bytes += buffer_length
        #if it can be resent/retried (not final) add it to the unack list
        #if 'retries' in params:
        #    packet.retries = params['retries']
        self.unacked_packets[packet.packet_id] = packet
        #otherwise, it can't be resent to get acked
        #else:
        #self.final_retry_packets[packet.packet_id] = packet

class CircuitManager(object):
    """ Manages a collection of circuits and provides some higher-level
        functionality to do so. """
    def __init__(self):
        self.circuit_map = {}
        self.unacked_circuits = {}

    def get_unacked_circuits(self):
        #go through circuits, if it has any unacked packets waiting ack, add
        #to a list
        pass

    def get_circuit(self, host):
        if (host.ip, host.port) in self.circuit_map:
            return self.circuit_map[(host.ip, host.port)]

        return None

    def add_circuit(self, host, packet_in_id):
        circuit = Circuit(host, packet_in_id)

        self.circuit_map[(host.ip, host.port)] = circuit
        return circuit

    def remove_circuit_data(self, host):
        if (host.ip, host.port) in self.circuit_map:
            del self.circuit_map[(host.ip, host.port)]

    def is_circuit_alive(self, host):
        if (host.ip, host.port) not in self.circuit_map:
            return False

        circuit = self.circuit_map[(host.ip, host.port)]
        return circuit.is_alive