import socket
from hashtree import HashTree
from networkers import NetworkReader,NetworkWriter
import collections
import sys

import config as conf

# debug copy default file
import shutil
origFilename=sys.argv[1]
filename=origFilename+"_"
shutil.copyfile(origFilename,filename)


class Connection:
	def __init__(self,server_socket):
		self.socket, address = server_socket.accept()
		print('Connected by', address)
		fr=self.socket.makefile(mode="rb")
		fw=self.socket.makefile(mode="wb")

		networkReader=NetworkReader(fr)
		networkReader.start()
		networkWriter=NetworkWriter(fw)
		networkWriter.start()

		self.incoming=networkReader.output # synchronized message queue
		self.outcoming=networkWriter.input

	def __enter__(self):
		return self.incoming,self.outcoming

	def __exit__(self, exc_type, exc_val, exc_tb):
		self.socket.close()


localTree=HashTree.fromFile(open(filename,mode="rb"))

ss = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
ss.bind(("",conf.port))
ss.listen(1)

blocksToTransfer=[]
nodeStack=collections.deque([0])

i1=-1


while True:
	with Connection(ss) as (incoming,outcoming):
		jsonData,binData=incoming.get(timeout=2)
		dataFile=open(filename,mode="rb+")

		if jsonData["command"]=="init":
			assert jsonData["blockSize"]==localTree.BLOCK_SIZE
			assert jsonData["blockCount"]==localTree.leafCount

		elif jsonData["command"]=="req": # !! index out of range
			print("received request for node #{0}".format(jsonData["index"]))
			nodeHash=localTree.store[jsonData["index"]]

			jsonResponse={"command":"send", "index":jsonData["index"], "dataType":"hash"}
			binResponse=nodeHash

			outcoming.put((jsonResponse,binResponse),timeout=2)

		elif jsonData["command"]=="send" and jsonData["dataType"]=="data": # needlessly allow hashes and data in mixed order
			print("received data block #{0}: {1}...{2}".format(jsonData["index"],binData[:5],binData[-5:]))

			i2=jsonData["index"]
			if i1+1!=i2:
				dataFile.seek(i2*localTree.BLOCK_SIZE)
			dataFile.write(binData)
			i1=i2

			# never update the hash tree

		elif jsonData["command"]=="end":
			print("closing...")
			break
	
		else: pass # !! error

dataFile.close()
sys.exit(0)