import errno
import time
import threading
import Queue
from struct import unpack, pack
import hashlib
import random
import select
import socket
from ssl import SSLError, SSL_ERROR_WANT_WRITE
import sys

from helper_generic import addDataPadding
from class_objectHashHolder import *
from addresses import *
from debug import logger
from inventory import PendingUpload
import protocol
import state
import throttle

# Every connection to a peer has a sendDataThread (and also a
# receiveDataThread).
class sendDataThread(threading.Thread):

    def __init__(self, sendDataThreadQueue):
        threading.Thread.__init__(self, name="sendData")
        self.sendDataThreadQueue = sendDataThreadQueue
        state.sendDataQueues.append(self.sendDataThreadQueue)
        self.data = ''
        self.objectHashHolderInstance = objectHashHolder(self.sendDataThreadQueue)
        self.objectHashHolderInstance.daemon = True
        self.objectHashHolderInstance.start()
        self.connectionIsOrWasFullyEstablished = False


    def setup(
        self,
        sock,
        HOST,
        PORT,
        streamNumber,
            someObjectsOfWhichThisRemoteNodeIsAlreadyAware):
        self.sock = sock
        self.peer = state.Peer(HOST, PORT)
        self.name = "sendData-" + self.peer.host.replace(":", ".") # log parser field separator
        self.streamNumber = []
        self.services = 0
        self.buffer = ""
        self.initiatedConnection = False
        self.remoteProtocolVersion = - \
            1  # This must be set using setRemoteProtocolVersion command which is sent through the self.sendDataThreadQueue queue.
        self.lastTimeISentData = int(
            time.time())  # If this value increases beyond five minutes ago, we'll send a pong message to keep the connection alive.
        self.someObjectsOfWhichThisRemoteNodeIsAlreadyAware = someObjectsOfWhichThisRemoteNodeIsAlreadyAware
        if streamNumber == -1:  # This was an incoming connection.
            self.initiatedConnection = False
        else:
            self.initiatedConnection = True
        #logger.debug('The streamNumber of this sendDataThread (ID: ' + str(id(self)) + ') at setup() is' + str(self.streamNumber))


    def sendVersionMessage(self):
        datatosend = protocol.assembleVersionMessage(
            self.peer.host, self.peer.port, state.streamsInWhichIAmParticipating, not self.initiatedConnection)  # the IP and port of the remote host, and my streamNumber.

        logger.debug('Sending version packet: ' + repr(datatosend))

        try:
            self.sendBytes(datatosend)
        except Exception as err:
            # if not 'Bad file descriptor' in err:
            logger.error('sock.sendall error: %s\n' % err)
            
        self.versionSent = 1

    def sendBytes(self, data = ""):
        self.buffer += data
        if len(self.buffer) < throttle.SendThrottle().chunkSize and self.sendDataThreadQueue.qsize() > 1:
            return

        while self.buffer and state.shutdown == 0:
            isSSL = False
            try:
                if ((self.services & protocol.NODE_SSL == protocol.NODE_SSL) and
                    self.connectionIsOrWasFullyEstablished and
                    protocol.haveSSL(not self.initiatedConnection)):
                    isSSL = True
                    amountSent = self.sslSock.send(self.buffer[:throttle.SendThrottle().chunkSize])
                else:
                    amountSent = self.sock.send(self.buffer[:throttle.SendThrottle().chunkSize])
            except socket.timeout:
                continue
            except SSLError as e:
                if e.errno == SSL_ERROR_WANT_WRITE:
                    select.select([], [self.sslSock], [], 10)
                    logger.debug('sock.recv retriable SSL error')
                    continue
                raise
            except socket.error as e:
                if e.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
                    select.select([], [self.sslSock if isSSL else self.sock], [], 10)
                    logger.debug('sock.recv retriable error')
                    continue
                if sys.platform.startswith('win') and e.errno in (errno.WSAEAGAIN, errno.WSAEWOULDBLOCK):
                    select.select([], [self.sslSock if isSSL else self.sock], [], 10)
                    logger.debug('sock.recv retriable error')
                    continue
                raise
            throttle.SendThrottle().wait(amountSent)
            self.lastTimeISentData = int(time.time())
            self.buffer = self.buffer[amountSent:]


    def run(self):
        logger.debug('sendDataThread starting. ID: ' + str(id(self)) + '. Number of queues in sendDataQueues: ' + str(len(state.sendDataQueues)))
        while True:
            self.sendBytes()
            deststream, command, data = self.sendDataThreadQueue.get()

            if deststream == 0 or deststream in self.streamNumber:
                if command == 'shutdown':
                    logger.debug('sendDataThread (associated with ' + str(self.peer) + ') ID: ' + str(id(self)) + ' shutting down now.')
                    break
                # When you receive an incoming connection, a sendDataThread is
                # created even though you don't yet know what stream number the
                # remote peer is interested in. They will tell you in a version
                # message and if you too are interested in that stream then you
                # will continue on with the connection and will set the
                # streamNumber of this send data thread here:
                elif command == 'setStreamNumber':
                    self.streamNumber = data
                    logger.debug('setting the stream number to %s', ', '.join(str(x) for x in self.streamNumber))
                elif command == 'setRemoteProtocolVersion':
                    specifiedRemoteProtocolVersion = data
                    logger.debug('setting the remote node\'s protocol version in the sendDataThread (ID: ' + str(id(self)) + ') to ' + str(specifiedRemoteProtocolVersion))
                    self.remoteProtocolVersion = specifiedRemoteProtocolVersion
                elif command == 'advertisepeer':
                    self.objectHashHolderInstance.holdPeer(data)
                elif command == 'sendaddr':
                    if self.connectionIsOrWasFullyEstablished: # only send addr messages if we have sent and heard a verack from the remote node
                        numberOfAddressesInAddrMessage = len(data)
                        payload = ''
                        for hostDetails in data:
                            timeLastReceivedMessageFromThisNode, streamNumber, services, host, port = hostDetails
                            payload += pack(
                                '>Q', timeLastReceivedMessageFromThisNode)  # now uses 64-bit time
                            payload += pack('>I', streamNumber)
                            payload += pack(
                                '>q', services)  # service bit flags offered by this node
                            payload += protocol.encodeHost(host)
                            payload += pack('>H', port)
    
                        payload = encodeVarint(numberOfAddressesInAddrMessage) + payload
                        packet = protocol.CreatePacket('addr', payload)
                        try:
                            self.sendBytes(packet)
                        except:
                            logger.error('sendaddr: self.sock.sendall failed')
                            break
                elif command == 'advertiseobject':
                    self.objectHashHolderInstance.holdHash(data)
                elif command == 'sendinv':
                    if self.connectionIsOrWasFullyEstablished: # only send inv messages if we have send and heard a verack from the remote node
                        payload = ''
                        for hash in data:
                            if hash not in self.someObjectsOfWhichThisRemoteNodeIsAlreadyAware:
                                payload += hash
                        if payload != '':
                            payload = encodeVarint(len(payload)/32) + payload
                            packet = protocol.CreatePacket('inv', payload)
                            try:
                                self.sendBytes(packet)
                            except:
                                logger.error('sendinv: self.sock.sendall failed')
                                break
                elif command == 'pong':
                    self.someObjectsOfWhichThisRemoteNodeIsAlreadyAware.clear() # To save memory, let us clear this data structure from time to time. As its function is to help us keep from sending inv messages to peers which sent us the same inv message mere seconds earlier, it will be fine to clear this data structure from time to time.
                    if self.lastTimeISentData < (int(time.time()) - 298):
                        # Send out a pong message to keep the connection alive.
                        logger.debug('Sending pong to ' + str(self.peer) + ' to keep connection alive.')
                        packet = protocol.CreatePacket('pong')
                        try:
                            self.sendBytes(packet)
                        except:
                            logger.error('send pong failed')
                            break
                elif command == 'sendRawData':
                    hash = None
                    if type(data) in [list, tuple]:
                        hash, data = data
                    try:
                        self.sendBytes(data)
                        PendingUpload().delete(hash)
                    except:
                        logger.error('Sending of data to ' + str(self.peer) + ' failed. sendDataThread thread ' + str(self) + ' ending now.', exc_info=True)
                        break
                elif command == 'connectionIsOrWasFullyEstablished':
                    self.connectionIsOrWasFullyEstablished = True
                    self.services, self.sslSock = data
            elif self.connectionIsOrWasFullyEstablished:
                logger.error('sendDataThread ID: ' + str(id(self)) + ' ignoring command ' + command + ' because the thread is not in stream ' + str(deststream) + ' but in streams ' + ', '.join(str(x) for x in self.streamNumber))
            self.sendDataThreadQueue.task_done()
        self.sendDataThreadQueue.task_done()

        try:
            self.sock.shutdown(socket.SHUT_RDWR)
            self.sock.close()
        except:
            pass
        state.sendDataQueues.remove(self.sendDataThreadQueue)
        PendingUpload().threadEnd()
        logger.info('sendDataThread ending. ID: ' + str(id(self)) + '. Number of queues in sendDataQueues: ' + str(len(state.sendDataQueues)))
        self.objectHashHolderInstance.close()
