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

# debug copy default file
import shutil
shutil.copyfile("serverFile_.txt","serverFile.txt")


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

HOST = ''                 # Symbolic name meaning all available interfaces
PORT = 50009              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print('Connected by', addr)
fr=conn.makefile(mode="rb")
fw=conn.makefile(mode="wb")

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

blocksToTransfer=[]
nodeStack=collections.deque([0])
incoming=networkReader.output # synchronized message queue
outcoming=networkWriter.input


while True:
  jsonData,binData=incoming.get(timeout=2)
  
  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:]))
    
    dataFile=open("serverFile.txt",mode="rb+")
    dataFile.seek(jsonData["index"]*localTree.BLOCK_SIZE)
    dataFile.write(binData)
    dataFile.close()
    
    # never update the hash tree
    
  elif jsonData["command"]=="end":
    print("closing...")
    break
  
  else: pass # !! error

# fr.close()
# fw.close()
conn.close()
sys.exit(0)