import collections

import socket

import ssl

import logging as log

from datetime import datetime

import config as conf

import stats

from util import Progress

from hashtree import HashTree,hashBlock

from netnode import BaseConnection,NetNode,FailedConnection

class DeniedConnection(Exception): pass

class Connection(BaseConnection):

	def __init__(self,host,port):

		super().__init__()

		sock=socket.socket(socket.AF_INET, socket.SOCK_STREAM)

		sslContext=ssl.create_default_context(cafile=conf.peers)

		sslContext.check_hostname=False

		sslContext.load_cert_chain(conf.certfile,conf.keyfile)

		self._socket=sslContext.wrap_socket(sock)

		try:

			self._socket.connect((host,port))

			log.exception(e)

			print("Couldn't connect to {0}:{1}".format(host,port))

			raise FailedConnection()

		except ssl.SSLError as e:

			log.exception(e)

			print("Error creating SSL connection to {0}:{1}".format(host,port))

			raise FailedConnection()

		self.createNetworkers()

		print("Connected to {0}".format(host))

class Client(NetNode):

	def __init__(self,filename,treeFile=""):

		print(datetime.now(), "initializing...")

		super().__init__(filename,treeFile)

	def init(self,action):

		jsonData={"command":"init", "blockSize":self._tree.BLOCK_SIZE, "blockCount":self._tree.leafCount, "version":conf.version, "action":action}

		self._outcoming.writeMsg(jsonData)

		jsonData,binData=self._incoming.readMsg()

		if jsonData["command"]=="deny":

			raise DeniedConnection()

		assert jsonData["command"]=="init"

	## Asks server for node hashes to determine which are to be transferred.

	#

	# Uses a binary HashTree, where item at k is hash of items at 2k+1, 2k+2.

	#

	# Requests nodes in order of a batch DFS. Needs stack of size O(treeDepth*batchSize). Nodes in each tree level are accessed in order.

	def negotiate(self):

		localTree=self._tree

		blocksToTransfer=[]

		nodeStack=collections.deque([0]) # root

		# determine which blocks to send

		print(datetime.now(), "negotiating:")

		progress=Progress(localTree.leafCount)

		while len(nodeStack)>0:

			indices=[]

			for i in range(conf.batchSize):

				indices.append(nodeStack.pop())

				if len(nodeStack)==0: break

			self._outcoming.writeMsg({"command":"req", "index":indices, "dataType":"hash"})

			jsonData,binData=self._incoming.readMsg()

			assert jsonData["index"]==indices

			assert jsonData["dataType"]=="hash"

			stats.logExchangedNode(len(indices))

			frontier=[]

			for (j,i) in enumerate(indices):

				(j1,j2)=[HashTree.HASH_LEN*ji for ji in (j,j+1)]

				if localTree.store[i]!=binData[j1:j2]:

					# ie. 0-6 nodes, 7-14 leaves. 2*6+2<15

					if 2*i+2<len(localTree.store): # inner node

						frontier.append(2*i+1)

						frontier.append(2*i+2)

					else:

						blocksToTransfer.append(i-localTree.leafStart) # leaf

						progress.p(i-localTree.leafStart)

			nodeStack.extend(reversed(frontier))

		progress.done()

		size=stats.formatBytes(len(blocksToTransfer)*self._tree.BLOCK_SIZE)

		print(datetime.now(), "{0} to transfer".format(size))

		return blocksToTransfer

	def sendData(self,blocksToTransfer):

		log.info(blocksToTransfer)

		dataFile=open(self._filename, mode="rb")

		i1=-1

		print(datetime.now(), "sending data:")

		progress=Progress(len(blocksToTransfer))

		for (k,i2) in enumerate(blocksToTransfer):

			jsonData={"command":"send", "index":i2, "dataType":"data"}

			if i1+1!=i2:

				dataFile.seek(i2*HashTree.BLOCK_SIZE)

			binData=dataFile.read(HashTree.BLOCK_SIZE)

			log.info("block #{0}: {1}...{2}".format(i2,binData[:5],binData[-5:]))

			self._outcoming.writeMsg(jsonData,binData)

			stats.logTransferredBlock()

			jsonData,binData=self._incoming.readMsg()

			assert jsonData["command"]=="ack" and jsonData["index"]==i2, jsonData

			i1=i2

			progress.p(k)

		progress.done()

		self._outcoming.writeMsg({"command":"end","action":"push"})

		log.info("closing session...")

		dataFile.close()

import os

import socket

import logging as log

import config as conf

from networkers import NetworkReader,NetworkWriter

from hashtree import HashTree

lockFile=os.path.join(conf.directory,"dirty.lock")

class FailedConnection(Exception): pass

class LockedException(Exception): pass

class BaseConnection: # abstract

	def __init__(self):

		self._socket=None

		self.incoming=None

		self.outcoming=None

	def createNetworkers(self):

		fr=self._socket.makefile(mode="rb")

		fw=self._socket.makefile(mode="wb")

		self.incoming=NetworkReader(fr)

		self.outcoming=NetworkWriter(fw)

	def __enter__(self):

		return self.incoming,self.outcoming

	def __exit__(self, exc_type, exc_val, exc_tb):

		try:

			self._socket.shutdown(socket.SHUT_RDWR)

			self._socket.close()

		except OSError:

			log.warning("broken connection")

class NetNode:

	def __init__(self,filename,treeFile=""):

		self._incoming=None

		self._outcoming=None

		self._filename=filename

		self._treeFile=treeFile

		if treeFile:

			self._tree=HashTree.load(treeFile)

		else:

			self._tree=HashTree.fromFile(filename)

		self._newLeaves=dict()

	def isLocked(self):

		return os.path.isfile(lockFile)

	def _lock(self):

		try:

			f=open(lockFile,"x")

			f.close()

		except FileExistsError:

			raise LockedException()

	def _unlock(self):

		os.remove(lockFile)

	def _updateTree(self):

		log.info("updating hash tree...")

		self._tree.batchUpdate(self._newLeaves.items())

		self._tree.save(self._treeFile)