import collections

import socket

import ssl

import logging as log

from datetime import datetime

import config as conf

import status

import stats

from util import Progress

from hashtree import HashTree, hash_block

from netnode import BaseConnection, NetNode, FailedConnection, LockedException, IncompatibleException

from datafile import DataFile

class DeniedConnection(Exception): pass

class Connection(BaseConnection):

	def __init__(self, host, port):

		super().__init__()

		sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

		ssl_context = ssl.create_default_context(cafile=conf.peers)

		ssl_context.check_hostname = False

		ssl_context.load_cert_chain(conf.certfile, conf.keyfile)

		self._socket = ssl_context.wrap_socket(sock)

		try:

			self._socket.connect((host, port))

		except (ConnectionRefusedError, OSError) as e:

			log.exception(e)

			print("Couldn't connect to {0}:{1}".format(host, port))

			raise FailedConnection()

		except ssl.SSLError as e:

			log.exception(e)

			print("Error creating SSL connection to {0}:{1}".format(host, port))

			raise FailedConnection()

		self.create_networkers()

		print("Connected to {0}".format(host))

class Client(NetNode):

	def __init__(self, filename, tree_file=""):

		print(datetime.now(), "initializing...")

		super().__init__(filename, tree_file)

	def init(self, action):

		json_data = {

			"command": "init",

			"blockSize": self._tree.BLOCK_SIZE,

			"blockCount": self._tree.leaf_count,

			"version": conf.version,

			"action": action

		}

		self._outcoming.write_msg(json_data)

		json_data, bin_data = self._incoming.read_msg()

		if json_data["command"] == "deny":

			if json_data["status"] == status.incompatible.version:

				raise DeniedConnection("Incompatible client version. Consider upgrading it.")

			raise DeniedConnection()

		assert json_data["command"] == "init"

		if json_data["version"] < conf.lowest_compatible:

			raise IncompatibleException("Incompatible server version. Consider upgrading it.")

	## Asks server for node hashes to determine which are to be transferred.

	#

	# Uses a binary HashTree, where item at k is hash of items at 2k+1, 2k+2.

	#

	# Requests nodes in order of a batch DFS. Needs a stack of size O(tree_depth*batch_size). Nodes in each tree level are accessed in order.

	def negotiate(self):

		local_tree = self._tree

		blocks_to_transfer = []

		node_stack = collections.deque([0])  # root

		# determine which blocks to send

		print(datetime.now(), "negotiating:")

		progress = Progress(local_tree.leaf_count)

		while len(node_stack) > 0:

			indices = []

			for i in range(conf.batch_size.hash):

				indices.append(node_stack.pop())

				if len(node_stack) == 0: break

			self._outcoming.write_msg({"command": "req", "index": indices, "dataType": "hash"})

			json_data, bin_data = self._incoming.read_msg()

			assert json_data["index"] == indices

			assert json_data["dataType"] == "hash"

			stats.log_exchanged_node(len(indices))

			frontier = []

			for (j, i) in enumerate(indices):

				(j1, j2) = [HashTree.HASH_LEN*ji for ji in (j, j+1)]

				if local_tree.store[i] != bin_data[j1:j2]:

					# ie. 0-6 nodes, 7-14 leaves. 2*6+2<15

					if 2*i+2 < len(local_tree.store):  # inner node

						frontier.append(2*i+1)

						frontier.append(2*i+2)

					else:

						blocks_to_transfer.append(i-local_tree.leaf_start)  # leaf

						progress.p(i-local_tree.leaf_start)

			node_stack.extend(reversed(frontier))

		progress.done()

		size = stats.format_bytes(len(blocks_to_transfer)*self._tree.BLOCK_SIZE)

		print(datetime.now(), "{0} to transfer".format(size))

		return blocks_to_transfer

	def send_data(self, blocks_to_transfer):

		log.info(blocks_to_transfer)

		data_file = DataFile.open(self._filename)

		print(datetime.now(), "sending data:")

		progress = Progress(len(blocks_to_transfer))

		for k in range(0, len(blocks_to_transfer), conf.batch_size.data):

			indices = []

			blocks = []

			for j in range(conf.batch_size.data):

				if k+j >= len(blocks_to_transfer): break

				i = blocks_to_transfer[k+j]

				block = data_file.read_from(i)

				indices.append(i)

				blocks.append(block)

				log.info("block #{0}: {1}...{2}".format(i, block[:5], block[-5:]))

				progress.p(k+j)

			if indices: self._send_data(indices, blocks)

		progress.done()

		self._outcoming.write_msg({"command": "end", "action": "push"})

		log.info("closing session...")

		data_file.close()

	def pull_data(self, blocks_to_transfer, ignore_lock=False):

		if not ignore_lock:

			try:

				self._lock()

			except LockedException:

				print(

					"The file is locked. Either (a) there's another pull going on (then wait or kill it), or (b) a previous pull ended prematurely and the file is probably corrupt (then repeat pull with -f for force).")

				return

		log.info(blocks_to_transfer)

		data_file = DataFile.open(self._filename, mode="rb+")

		print(datetime.now(), "receiving data:")

		progress = Progress(len(blocks_to_transfer))

		last_flushed = datetime.now().timestamp()

		for k in range(0, len(blocks_to_transfer), conf.batch_size.data):

			indices = blocks_to_transfer[k:k+conf.batch_size.data]

			self._outcoming.write_msg({"command": "req", "index": indices, "dataType": "data"})

			json_data, bin_data = self._incoming.read_msg()

			assert json_data["command"]=="send" and json_data["index"]==indices and json_data["dataType"]=="data", json_data

			for (j, i) in enumerate(indices):

				block = bin_data[j*HashTree.BLOCK_SIZE:(j+1)*HashTree.BLOCK_SIZE]

				data_file.write_at(i, block)

				log.info("block #{0}: {1}...{2}".format(i, block[:5], block[-5:]))

				if self._tree_file:

					self._new_leaves[i+self._tree.leaf_start] = hash_block(block)

					t = datetime.now().timestamp()

						last_flushed = t

				stats.log_transferred_block()

				progress.p(k+j)

		progress.done()

		self._outcoming.write_msg({"command": "end"})

		log.info("closing session...")

		data_file.close()

		self._unlock()

		if self._tree_file:

			self._update_tree()

	def _send_data(self, indices, blocks):

		json_data = {"command": "send", "index": indices, "dataType": "data"}

		bin_data = b"".join(blocks)

		self._outcoming.write_msg(json_data, bin_data)

		stats.log_transferred_block(len(indices))

		json_data, bin_data = self._incoming.read_msg()

		assert json_data["command"]=="ack" and json_data["index"]==indices, json_data

	def set_connection(self, connection):

		(self._incoming, self._outcoming) = connection

import os

import socket

import logging as log

import config as conf

from networkers import NetworkReader, NetworkWriter

from hashtree import HashTree

lock_file = 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 create_networkers(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, tree_file=""):

		self._incoming = None

		self._outcoming = None

		self._filename = filename

		self._tree_file = tree_file

		if tree_file:

			self._tree = HashTree.load(tree_file)

		else:

			self._tree = HashTree.from_file(filename)

		self._new_leaves = dict()

	def is_locked(self):

		return os.path.isfile(lock_file)

	def _lock(self):

		try:

			f = open(lock_file, "x")

			f.close()

		except FileExistsError:

	def _unlock(self):

		os.remove(lock_file)

	def _update_tree(self):

		log.info("updating hash tree...")

		self._tree.batch_update(self._new_leaves.items())

		self._tree.save(self._tree_file)

		self._new_leaves = dict()

		log.info("tree updated")

from datetime import datetime

import socket

import ssl

import multiprocessing

import logging as log

from hashtree import hash_block

import config as conf

import status

from datafile import DataFile

class Connection(BaseConnection):

	def __init__(self, server_socket, ssl_context):

		super().__init__()

		sock, address = server_socket.accept()

		peer = sock.getpeername()

		try:

			self._socket = ssl_context.wrap_socket(sock, server_side=True)

		except (ssl.SSLError,OSError) as e:

			log.warning("Failed to establish an SSL connection from {0}.".format(peer))

			raise e

		log.info('Connected by {0}'.format(address))

		self.create_networkers()

class Miniserver:

	def __init__(self, filename, tree_file=""):

		self._filename = filename

		self._tree_file = tree_file

		self._ssl = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH, cafile=conf.peers)

		self._ssl.verify_mode = ssl.CERT_REQUIRED

		self._ssl.load_cert_chain(conf.certfile, conf.keyfile)

		self._ss = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

		self._ss.bind(("", conf.port))

		self._ss.listen(1)

	def serve(self):

		p = None

		with self._ss:

			while True:

				try: connection = Connection(self._ss, self._ssl)

				except (ssl.SSLError, OSError): continue

				if p and p.is_alive():

					with connection as c:

						c[0].read_msg()

						c[1].write_msg({"command": "deny", "status":status.locked})

					continue

				p = multiprocessing.Process(target=Server.run, args=(connection, self._filename, self._tree_file))

				p.start()

class Server(NetNode):

	def __init__(self, connection, filename, tree_file=""):

		super().__init__(filename, tree_file)

		(self._incoming, self._outcoming) = connection

		self.BLOCK_SIZE = self._tree.BLOCK_SIZE

		self._data_file_obj = None

		self._last_flushed = 0

	@staticmethod

	def run(connection, *args):

		with connection as c:

			s = Server(c, *args)

			s.serve()

	@property

	def _data_file(self):

		if not self._data_file_obj:

			self._data_file_obj = DataFile.open(self._filename, mode="rb+")

		return self._data_file_obj

	def serve(self):

		try:

			while self._serve_one(): pass

		except (AssertionError, ConnectionResetError) as e:

			log.warning(e)

	def _serve_one(self):

		json_data, bin_data = self._incoming.read_msg()

		if json_data["command"]=="init":

			if json_data["blockSize"]!=self.BLOCK_SIZE or json_data["blockCount"]!=self._tree.leaf_count:

				self._outcoming.write_msg({"command": "deny", "status": status.incompatible.parameters})

			if json_data["version"]<conf.lowest_compatible:

				self._outcoming.write_msg({"command": "deny", "status": status.incompatible.version})

			if json_data["action"]=="pull" and self.is_locked():

				self._outcoming.write_msg({"command": "deny", "status": status.locked})

			if json_data["action"]=="push" and not self.is_locked():

				self._lock()

			self._last_flushed = datetime.now().timestamp()

			self._outcoming.write_msg({"command": "init", "version": conf.version})

		elif json_data["command"]=="req":

			if json_data["dataType"]=="data":

				self._outcoming.write_msg(*self._request_data(json_data["index"]))

			else:

				self._outcoming.write_msg(*self._request_hash(json_data["index"]))

		elif json_data["command"]=="send" and json_data["dataType"]=="data":

			self._outcoming.write_msg(*self._receive_data(json_data, bin_data))

		elif json_data["command"]=="end":

			self._finalize()

			if json_data.get("action")=="push": self._unlock()

			return False

		else:

			assert False, json_data["command"]

		return True

	def _request_hash(self, indices):

		log.info("received request for nodes {0}".format(indices))

		assert all(i<len(self._tree.store) for i in indices)

		hashes = [self._tree.store[i] for i in indices]

		json_response = {"command": "send", "index": indices, "dataType": "hash"}

		bin_response = b"".join(hashes)

		return (json_response, bin_response)

	def _request_data(self, index):

		log.info("received request for data blocks {0}".format(index))

		json_response = {"command": "send", "index": index, "dataType": "data"}

		blocks = []

		for i in index:

			blocks.append(self._data_file.read_from(i))

		return (json_response, b"".join(blocks))

	def _receive_data(self, json_data, bin_data):

		if not self.is_locked(): self._lock()

		log.info("received data blocks {0}: {1}...{2}".format(json_data["index"], bin_data[:5], bin_data[-5:]))

		indices = json_data["index"]

		for (i, k) in enumerate(indices):

			block = bin_data[i*self.BLOCK_SIZE:(i+1)*self.BLOCK_SIZE]

			self._data_file.write_at(k, block)

			if self._tree_file:

				self._new_leaves[k+self._tree.leaf_start] = hash_block(block)

		t = datetime.now().timestamp()

			self._last_flushed = t

		return ({"command": "ack", "index": indices},)

	def _finalize(self):

		log.info("closing session...")

		self._data_file.close()

		self._data_file_obj = None

		if self._tree_file:

			self._update_tree()

		log.info("done")