import sys
import os.path
import logging as log
from argparse import ArgumentParser

from util import spawnDaemon, splitHost
import config as conf
import stats
from hashtree import HashTree
from client import Client, Connection as ClientConnection, FailedConnection, DeniedConnection, IncompatibleException
from server import Miniserver


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)
	if os.path.isfile(args.treefile):
		treeMod = os.stat(args.treefile).st_mtime
		dataMod = os.stat(args.datafile).st_mtime
		if dataMod<treeMod and not args.force:
			print("tree file is up to date")
			return

	tree = HashTree.fromFile(args.datafile)
	tree.save(args.treefile)


def push(args):
	_checkFile(args.datafile)
	if args.tree:
		_checkFile(args.tree)
	if args.host: conf.hosts = [args.host]
	if args.port: conf.port = args.port

	c = Client(args.datafile,args.tree)
	for h in conf.hosts:
		host = splitHost(h,conf.port)
		stats.reset()
		try:
			with ClientConnection(*host) as con:
				c.setConnection(con)
				c.init("push")
				blocksToTransfer = c.negotiate()
				c.sendData(blocksToTransfer)
			print()
			print(stats.report())
			print()
		except FailedConnection: pass
		except DeniedConnection as e:
			print("Server {0}:{1} denied connection.".format(*host))
			print(e)
		except IncompatibleException as e: print(e)

def pull(args):
	_checkFile(args.datafile)
	if args.tree:
		_checkFile(args.tree)
	if args.host: conf.hosts = [args.host]
	if args.port: conf.port = args.port

	c = Client(args.datafile, args.tree)
	host = splitHost(conf.hosts[0], conf.port)
	try:
		with ClientConnection(*host) as con:
			c.setConnection(con)
			c.init("pull")
			blocksToTransfer = c.negotiate()
			c.pullData(blocksToTransfer, args.force)
		print()
		print(stats.report())
	except FailedConnection: pass
	except DeniedConnection as e:
		print("Server {0}:{1} denied connection.".format(*host))
		print(e)


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

	try:
		s = Miniserver(args.datafile,args.tree)
		spawnDaemon(s.serve)
	except Exception as e:
		log.exception("exception: %s", e)
		print("Failed to start:\n  ", e)


parser = ArgumentParser()
subparsers = parser.add_subparsers()

pBuild = subparsers.add_parser("build")
pBuild.add_argument("-f", "--force", action="store_true", help="force tree rebuild")
pBuild.add_argument("treefile", help="stored hash tree location")
pBuild.add_argument("datafile")
pBuild.set_defaults(func=buildTree)

pUpdate = subparsers.add_parser("push")
pUpdate.add_argument("-p", "--port", type=int)
pUpdate.add_argument("--host")
pUpdate.add_argument("-t", "--tree", help="stored hash tree location")
pUpdate.add_argument("datafile")
pUpdate.set_defaults(func=push)

pUpdate = subparsers.add_parser("pull")
pUpdate.add_argument("-p", "--port", type=int)
pUpdate.add_argument("--host")
pUpdate.add_argument("-t", "--tree", help="stored hash tree location")
pUpdate.add_argument("-f", "--force", action="store_true", help="ignore lock file")
pUpdate.add_argument("datafile")
pUpdate.set_defaults(func=pull)

pServe = subparsers.add_parser("serve")
pServe.add_argument("-p", "--port", type=int)
pServe.add_argument("--host")
pServe.add_argument("-t", "--tree", help="stored hash tree location")
pServe.add_argument("datafile")
pServe.set_defaults(func=serve)

args = parser.parse_args()
try: args.func(args)
except AttributeError:
	parser.print_help()