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

from networkers import NetworkReader,NetworkWriter

class Connection:

	def __init__(self):

		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)

		self._socket.connect((conf.hosts[0], conf.port))

		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):

		self._socket.shutdown(socket.SHUT_RDWR)

		self._socket.close()

class Client:

	def __init__(self,filename):

		self._incoming=None

		self._outcoming=None

		self._filename=filename

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

		self._localTree=HashTree.fromFile(self._filename)

	## 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._localTree

		blocksToTransfer=[]

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

		# initialize session

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

		self._outcoming.writeMsg(jsonData)

		jsonData,binData=self._incoming.readMsg()

		assert jsonData["command"]=="ack"

		# determine which blocks to send

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

		progress=Progress(localTree.leafCount)

		while len(nodeStack)>0:

			indices=[]

			for i in range(256):

				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]:

						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()

		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"})

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

		dataFile.close()

	def pullData(self,blocksToTransfer):

		log.info(blocksToTransfer)

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

		i1=-1

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

		progress=Progress(len(blocksToTransfer))

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

			self._outcoming.writeMsg({"command":"req", "index":i2, "dataType":"data"})

			jsonData,binData=self._incoming.readMsg()

			assert jsonData["command"]=="send" and jsonData["index"]==i2 and jsonData["dataType"]=="data", jsonData

			if i1+1!=i2:

				dataFile.seek(i2*HashTree.BLOCK_SIZE)

			dataFile.write(binData)

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

			stats.logTransferredBlock()

			i1=i2

			progress.p(k)

		progress.done()

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

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

		dataFile.close()

	def setConnection(self,connection):

		(self._incoming,self._outcoming)=connection