import sys

import os.path

from argparse import ArgumentParser

import config as conf

from hashtree import HashTree

from client import Client

from server import Server

def _checkFile(f):

	if not os.path.isfile(f):

		print("invalid file specified:",f,file=sys.stderr)

		sys.exit(1)

def buildTree(args):

	_checkFile(args.datafile)

	tree=HashTree.fromFile(args.datafile)

	tree.save(args.treefile)

def update(args):

	_checkFile(args.datafile)

	if args.host: conf.hosts.insert(0,args.host)

	if args.port: conf.port=args.port

	c=Client(args.datafile)

	blocksToTransfer=c.negotiate()

	c.sendData(blocksToTransfer)

def serve(args):

	_checkFile(args.datafile)

	if args.tree:

		_checkFile(args.tree)

	if args.host: conf.hosts.insert(0,args.host)

	if args.port: conf.port=args.port

	s.serve()

parser=ArgumentParser()

subparsers=parser.add_subparsers()

pBuild=subparsers.add_parser("build")

pBuild.add_argument("treefile", help="stored hash tree location")

pBuild.add_argument("datafile")

pBuild.set_defaults(func=buildTree)

pUpdate=subparsers.add_parser("update")

pUpdate.add_argument("-p","--port",type=int)

pUpdate.add_argument("--host",default="127.0.0.1")

pUpdate.add_argument("datafile")

pUpdate.set_defaults(func=update)

pServe=subparsers.add_parser("serve")

pServe.add_argument("-p","--port",type=int)

pServe.add_argument("--host",default="")

pServe.add_argument("-t","--tree",help="stored hash tree location")

pServe.add_argument("datafile")

pServe.set_defaults(func=serve)

args=parser.parse_args()

args.func(args)