import os
import socket
import logging as log

import config as conf
from networkers import NetworkReader,NetworkWriter
from hashtree import HashTree


lockFile=os.path.join(conf.directory,"dirty.lock")


class FailedConnection(Exception): pass
class LockedException(Exception): pass
class IncompatibleException(Exception): pass


class BaseConnection: # abstract
	def __init__(self):
		self._socket=None
		self.incoming=None
		self.outcoming=None

	def createNetworkers(self):
		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):
		try:
			self._socket.shutdown(socket.SHUT_RDWR)
			self._socket.close()
		except OSError:
			log.warning("broken connection")


class NetNode:
	def __init__(self,filename,treeFile=""):
		self._incoming=None
		self._outcoming=None

		self._filename=filename
		self._treeFile=treeFile

		if treeFile:
			self._tree=HashTree.load(treeFile)
		else:
			self._tree=HashTree.fromFile(filename)

		self._newLeaves=dict()

	def isLocked(self):
		return os.path.isfile(lockFile)

	def _lock(self):
		try:
			f=open(lockFile,"x")
			f.close()
		except FileExistsError:
			raise LockedException()

	def _unlock(self):
		os.remove(lockFile)

	def _updateTree(self):
		log.info("updating hash tree...")
		self._tree.batchUpdate(self._newLeaves.items())
		self._tree.save(self._treeFile)
		log.info("tree updated")