from __future__ import division

import random
import time
import traceback

from twisted.internet import defer, protocol, reactor

from bitcoin import p2p as bitcoin_p2p
from bitcoin import data as bitcoin_data
from p2pool import data as p2pool_data
import util

# mode
#     0: send hash first (high latency, low bandwidth)
#     1: send entire share (low latency, high bandwidth)

class Protocol(bitcoin_p2p.BaseProtocol):
    version = 1
    sub_version = ''
    
    def __init__(self, node):
        self.node = node
        
        self._prefix = self.node.net.PREFIX
    
    use_checksum = True
    
    message_version = bitcoin_data.ComposedType([
        ('version', bitcoin_data.StructType('<I')),
        ('services', bitcoin_data.StructType('<Q')),
        ('addr_to', bitcoin_data.address_type),
        ('addr_from', bitcoin_data.address_type),
        ('nonce', bitcoin_data.StructType('<Q')),
        ('sub_version', bitcoin_data.VarStrType()),
        ('mode', bitcoin_data.StructType('<I')),
        ('state', bitcoin_data.ComposedType([
            ('chain_id', p2pool_data.chain_id_type),
            ('highest', bitcoin_data.ComposedType([
                ('hash', bitcoin_data.HashType()),
                ('height', bitcoin_data.StructType('<Q')),
            ])),
        ])),
    ])
    
    message_update_mode = bitcoin_data.ComposedType([
        ('mode', bitcoin_data.StructType('<I')),
    ])
    
    message_ping = bitcoin_data.ComposedType([])
    
    message_addrme = bitcoin_data.ComposedType([
        ('port', bitcoin_data.StructType('<H')),
    ])
    message_addrs = bitcoin_data.ComposedType([
        ('addrs', bitcoin_data.ListType(bitcoin_data.ComposedType([
            ('timestamp', bitcoin_data.StructType('<Q')),
            ('address', bitcoin_data.address_type),
        ]))),
    ])
    message_getaddrs = bitcoin_data.ComposedType([
        ('count', bitcoin_data.StructType('<I')),
    ])
    
    message_gettobest = bitcoin_data.ComposedType([
        ('chain_id', p2pool_data.chain_id_type),
        ('have', bitcoin_data.ListType(bitcoin_data.HashType())),
    ])
    message_getshares = bitcoin_data.ComposedType([
        ('chain_id', p2pool_data.chain_id_type),
        ('hashes', bitcoin_data.ListType(bitcoin_data.HashType())),
    ])
    
    message_share0s = bitcoin_data.ComposedType([
        ('chains', bitcoin_data.ListType(bitcoin_data.ComposedType([
            ('chain_id', p2pool_data.chain_id_type),
            ('hashes', bitcoin_data.ListType(bitcoin_data.HashType())),
        ]))),
    ])
    message_share1s = bitcoin_data.ComposedType([
        ('share1s', bitcoin_data.ListType(p2pool_data.share1_type)),
    ])
    message_share2s = bitcoin_data.ComposedType([
        ('share2s', bitcoin_data.ListType(bitcoin_data.block_type)),
    ])
    
    other_version = None
    node_var_watch = None
    connected2 = False
    
    @property
    def mode(self):
        return min(self.node.mode_var.value, self.other_mode_var.value)
    
    def connectionMade(self):
        bitcoin_p2p.BaseProtocol.connectionMade(self)
        
        chain = self.node.current_work.value['current_chain']
        highest_share2 = chain.get_highest_share2()
        self.send_version(
            version=self.version,
            services=0,
            addr_to=dict(
                services=0,
                address='::ffff:' + self.transport.getPeer().host,
                port=self.transport.getPeer().port,
            ),
            addr_from=dict(
                services=0,
                address='::ffff:' + self.transport.getHost().host,
                port=self.transport.getHost().port,
            ),
            nonce=self.node.nonce,
            sub_version=self.sub_version,
            mode=self.node.mode_var.value,
            state=dict(
                chain_id=p2pool_data.chain_id_type.unpack(chain.chain_id_data),
                highest=dict(
                    hash=highest_share2.share.hash if highest_share2 is not None else 2**256-1,
                    height=highest_share2.height if highest_share2 is not None else 0,
                ),
            ),
        )
        
        self.node_var_watch = self.node.mode_var.changed.watch(lambda new_mode: self.send_set_mode(mode=new_mode))
        
        reactor.callLater(10, self._connect_timeout)
    
    def _connect_timeout(self):
        if not self.connected2 and self.transport.connected:
            print 'Handshake timed out, disconnecting from %s:%i' % (self.transport.getPeer().host, self.transport.getPeer().port)
            self.transport.loseConnection()
    
    @defer.inlineCallbacks
    def _think(self):
        while self.connected2:
            self.send_ping()
            yield util.sleep(random.expovariate(1/100))
    
    @defer.inlineCallbacks
    def _think2(self):
        while self.connected2:
            self.send_addrme(port=self.node.port)
            #print 'sending addrme'
            yield util.sleep(random.expovariate(1/100))
    
    def handle_version(self, version, services, addr_to, addr_from, nonce, sub_version, mode, state):
        self.other_version = version
        self.other_services = services
        self.other_mode_var = util.Variable(mode)
        
        if nonce == self.node.nonce:
            #print 'Detected connection to self, disconnecting from %s:%i' % (self.transport.getPeer().host, self.transport.getPeer().port)
            self.transport.loseConnection()
            return
        if nonce in self.node.peers:
            print 'Detected duplicate connection, disconnecting from %s:%i' % (self.transport.getPeer().host, self.transport.getPeer().port)
            self.transport.loseConnection()
            return
        
        self.nonce = nonce
        self.connected2 = True
        self.node.got_conn(self)
        
        self._think()
        self._think2()
        
        if state['highest']['hash'] != 2**256 - 1:
            self.handle_share0s(chains=[dict(
                chain_id=state['chain_id'],
                hashes=[state['highest']['hash']],
            )])
    
    def handle_set_mode(self, mode):
        self.other_mode_var.set(mode)
    
    def handle_ping(self):
        pass
    
    def handle_addrme(self, port):
        host = self.transport.getPeer().host
        #print 'addrme from', host, port
        if host == '127.0.0.1':
            if random.random() < .8 and self.node.peers:
                random.choice(self.node.peers.values()).send_addrme(port=port) # services...
        else:
            self.node.got_addr(('::ffff:' + self.transport.getPeer().host, port), self.other_services, int(time.time()))
            if random.random() < .8 and self.node.peers:
                random.choice(self.node.peers.values()).send_addrs(addrs=[
                    dict(
                        address=dict(
                            services=self.other_services,
                            address='::ffff:' + host,
                            port=port,
                        ),
                        timestamp=int(time.time()),
                    ),
                ])
    def handle_addrs(self, addrs):
        for addr_record in addrs:
            self.node.got_addr((addr_record['address']['address'], addr_record['address']['port']), addr_record['address']['services'], min(int(time.time()), addr_record['timestamp']))
            if random.random() < .8 and self.node.peers:
                random.choice(self.node.peers.values()).send_addrs(addrs=[addr_record])
    def handle_getaddrs(self, count):
        self.send_addrs(addrs=[
            dict(
                timestamp=self.node.addr_store[host, port][2],
                address=dict(
                    services=self.node.addr_store[host, port][0],
                    address=host,
                    port=port,
                ),
            ) for host, port in
            random.sample(self.node.addr_store.keys(), min(count, len(self.node.addr_store)))
        ])
    
    def handle_gettobest(self, chain_id, have):
        self.node.handle_get_to_best(p2pool_data.chain_id_type.pack(chain_id), have, self)
    
    def handle_getshares(self, chain_id, hashes):
        self.node.handle_get_shares(p2pool_data.chain_id_type.pack(chain_id), hashes, self)
    
    def handle_share0s(self, chains):
        for chain in chains:
            for hash_ in chain['hashes']:
                self.node.handle_share_hash(p2pool_data.chain_id_type.pack(chain['chain_id']), hash_, self)
    def handle_share1s(self, share1s):
        for share1 in share1s:
            hash_ = bitcoin_data.block_hash(share1['header'])
            if hash_ <= bitcoin_data.bits_to_target(share1['header']['bits']):
                print 'Dropping peer %s:%i due to invalid share' % (self.transport.getPeer().host, self.transport.getPeer().port)
                self.transport.loseConnection()
                return
            share = p2pool_data.Share(share1['header'], gentx=share1['gentx'])
            self.node.handle_share(share, self)
    def handle_share2s(self, share2s):
        for share2 in share2s:
            hash_ = bitcoin_data.block_hash(share2['header'])
            if not hash_ <= bitcoin_data.bits_to_target(share2['header']['bits']):
                print 'Dropping peer %s:%i due to invalid share' % (self.transport.getPeer().host, self.transport.getPeer().port)
                self.transport.loseConnection()
                return
            share = p2pool_data.Share(share2['header'], txs=share2['txs'])
            self.node.handle_share(share, self)
    
    def send_share(self, share, full=False):
        if share.hash <= bitcoin_data.bits_to_target(share.header['bits']):
            self.send_share2s(share2s=[share.as_block()])
        else:
            if self.mode == 0 and not full:
                self.send_share0s(chains=[dict(
                    chain_id=p2pool_data.chain_id_type.unpack(share.chain_id_data),
                    hashes=[share.hash],
                )])
            elif self.mode == 1 or full:
                self.send_share1s(share1s=[dict(
                    header=share.header,
                    gentx=share.gentx,
                )])
            else:
                raise ValueError(self.mode)
    
    def connectionLost(self, reason):
        if self.node_var_watch is not None:
            self.node.mode_var.changed.unwatch(self.node_var_watch)
        
        if self.connected2:
            self.node.lost_conn(self)

class ServerFactory(protocol.ServerFactory):
    def __init__(self, node):
        self.node = node
    
    def buildProtocol(self, addr):
        p = Protocol(self.node)
        p.factory = self
        return p

class ClientFactory(protocol.ClientFactory):
    def __init__(self, node):
        self.node = node
    
    def buildProtocol(self, addr):
        p = Protocol(self.node)
        p.factory = self
        return p
    
    def startedConnecting(self, connector):
        self.node.attempt_started(connector)
    
    def clientConnectionFailed(self, connector, reason):
        self.node.attempt_failed(connector)
    
    def clientConnectionLost(self, connector, reason):
        self.node.attempt_ended(connector)

addrdb_key = bitcoin_data.ComposedType([
    ('address', bitcoin_data.IPV6AddressType()),
    ('port', bitcoin_data.StructType('>H')),
])
addrdb_value = bitcoin_data.ComposedType([
    ('services', bitcoin_data.StructType('<Q')),
    ('first_seen', bitcoin_data.StructType('<Q')),
    ('last_seen', bitcoin_data.StructType('<Q')),
])

class AddrStore(util.DictWrapper):
    def encode_key(self, (address, port)):
        return addrdb_key.pack(dict(address=address, port=port))
    def decode_key(self, encoded_key):
        k = addrdb_key.unpack(encoded_key)
        return k['address'], k['port']
    
    def encode_value(self, (services, first_seen, last_seen)):
        return addrdb_value.pack(dict(services=services, first_seen=first_seen, last_seen=last_seen))
    def decode_value(self, encoded_value):
        v = addrdb_value.unpack(encoded_value)
        return v['services'], v['first_seen'], v['last_seen']

class Node(object):
    def __init__(self, current_work, port, net, addr_store=None, preferred_addrs=[], mode=0, desired_peers=10, max_attempts=100):
        if addr_store is None:
            addr_store = {}
        
        self.port = port
        self.net = net
        self.addr_store = AddrStore(addr_store)
        self.preferred_addrs = preferred_addrs
        self.mode_var = util.Variable(mode)
        self.desired_peers = desired_peers
        self.max_attempts = max_attempts
        self.current_work = current_work
        
        self.nonce = random.randrange(2**64)
        self.attempts = {}
        self.peers = {}
        self.running = False
    
    def start(self):
        if self.running:
            raise ValueError('already running')
        
        self.running = True
        
        self.listen_port = reactor.listenTCP(self.port, ServerFactory(self))
        
        self._think()
        self._think2()
    
    @defer.inlineCallbacks
    def _think(self):
        while self.running:
            try:
                if len(self.peers) < self.desired_peers and len(self.attempts) < self.max_attempts and (len(self.preferred_addrs) or len(self.addr_store)):
                    if (random.randrange(2) and len(self.preferred_addrs)) or not len(self.addr_store):
                        host, port = random.choice(self.preferred_addrs)
                    else:
                        host2, port = random.choice(self.addr_store.keys())
                        prefix = '::ffff:'
                        if not host2.startswith(prefix):
                            raise ValueError('invalid address')
                        host = host2[len(prefix):]
                    
                    if (host, port) not in self.attempts:
                        #print 'Trying to connect to', host, port
                        reactor.connectTCP(host, port, ClientFactory(self), timeout=10)
            except:
                traceback.print_exc()
            
            yield util.sleep(random.expovariate(1/5))
    
    @defer.inlineCallbacks
    def _think2(self):
        while self.running:
            try:
                if len(self.addr_store) < self.preferred_addrs and self.peers:
                    random.choice(self.peers.values()).send_getaddrs(count=8)
            except:
                traceback.print_exc()
            
            yield util.sleep(random.expovariate(1/20))
    
    def stop(self):
        if not self.running:
            raise ValueError('already stopped')
        
        self.running = False
        
        self.listen_port.stopListening()
    
    
    def attempt_started(self, connector):
        host, port = connector.getDestination().host, connector.getDestination().port
        if (host, port) in self.attempts:
            raise ValueError('already have attempt')
        self.attempts[host, port] = connector
    
    def attempt_failed(self, connector):
        self.attempt_ended(connector)
    
    def attempt_ended(self, connector):
        host, port = connector.getDestination().host, connector.getDestination().port
        if (host, port) not in self.attempts:
            raise ValueError("don't have attempt")
        if connector is not self.attempts[host, port]:
            raise ValueError('wrong connector')
        del self.attempts[host, port]
    
    
    def got_conn(self, conn):
        if conn.nonce in self.peers:
            raise ValueError('already have peer')
        self.peers[conn.nonce] = conn
        
        print 'Connected to peer %s:%i' % (conn.transport.getPeer().host, conn.transport.getPeer().port)
    
    def lost_conn(self, conn):
        if conn.nonce not in self.peers:
            raise ValueError("don't have peer")
        if conn is not self.peers[conn.nonce]:
            raise ValueError('wrong conn')
        del self.peers[conn.nonce]
        
        print 'Lost peer %s:%i' % (conn.transport.getPeer().host, conn.transport.getPeer().port)
    
    
    def got_addr(self, (host, port), services, timestamp):
        if (host, port) in self.addr_store:
            old_services, old_first_seen, old_last_seen = self.addr_store[host, port]
            self.addr_store[host, port] = services, old_first_seen, max(old_last_seen, timestamp)
        else:
            self.addr_store[host, port] = services, timestamp, timestamp
    
    def handle_share(self, share, peer):
        print 'handle_share', (share, peer)
    
    def handle_share_hash(self, chain_id_data, hash, peer):
        print 'handle_share_hash', (chain_id_data, hash, peer)
    
    def handle_get_to_best(self, chain_id_data, have, peer):
        print 'handle_get_to_best', (chain_id_data, have, peer)
    
    def handle_get_shares(self, chain_id_data, hashes, peer):
        print 'handle_get_shares', (chain_id_data, hashes, peer)

if __name__ == '__main__':
    p = random.randrange(2**15, 2**16)
    for i in xrange(5):
        p2 = random.randrange(2**15, 2**16)
        print p, p2
        n = Node(p2, True, {addrdb_key.pack(dict(address='::ffff:' + '127.0.0.1', port=p)): addrdb_value.pack(dict(services=0, first_seen=int(time.time())-10, last_seen=int(time.time())))})
        n.start()
        p = p2
    
    reactor.run()