from hashtree import HashTree
import collections
import socket
import logging as log

import config as conf
from networkers import NetworkReader,NetworkWriter


class Connection:
	def __init__(self):
		self.socket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
		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.close()


class Client:
	def __init__(self,filename):
		self.filename=filename

	def negotiate(self):
		localTree=HashTree.fromFile(self.filename)
		blocksToTransfer=[]
		nodeStack=collections.deque([0]) # root

		# initialize session
		with Connection() as (incoming,outcoming):
			jsonData={"command":"init", "blockSize":localTree.BLOCK_SIZE, "blockCount":localTree.leafCount, "version":conf.version}
			outcoming.writeMsg(jsonData)

		# determine which blocks to send
		while len(nodeStack)>0:
			with Connection() as (incoming,outcoming):
				i=nodeStack.pop()
				outcoming.writeMsg({"command":"req", "index":i})

				jsonData,binData=incoming.readMsg()
				assert jsonData["index"]==i
				assert jsonData["dataType"]=="hash"

				if localTree.store[i]!=binData:
					if 2*i+3<len(localTree.store): # inner node
						nodeStack.append(2*i+2)
						nodeStack.append(2*i+1)
					else: blocksToTransfer.append(i-localTree.leafStart) # leaf

		return blocksToTransfer

	def sendData(self,blocksToTransfer):
		log.info(blocksToTransfer)
		dataFile=open(self.filename,mode="rb")
		i1=-1

		for i2 in blocksToTransfer:
			with Connection() as (incoming,outcoming):
				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:]))

				outcoming.writeMsg(jsonData,binData)
				i1=i2

		with Connection() as (incoming,outcoming):
			outcoming.writeMsg({"command":"end"})

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