import asyncio
from ws.connection import IConnection
import json


class MsgIo:
	def __init__(self, key, send):
		self.key = key
		self.sender = send
		self.receiver = None

	def set_recv_handler(self, handler):
		self.receiver = handler

	async def on_recv(self, data):
		print("MessageHandler {}".format(data))
		if self.receiver is not None:
			await self.receiver(data[self.key])

	async def send(self, data):
		return await self.sender({self.key: data})

	def can_key(self, key):
		return self.key == key

	def get_key(self):
		return self.key


class Value:
	def __init__(self, initial=None):
		self.value = initial
		self.has_changed = True

	def set(self, value):
		self.has_changed = self.value != value
		self.value = value

	def is_changed(self):
		return self.has_changed

	def get(self):
		self.has_changed = False
		return self.value


class MessageDispatcher(IConnection):
	def __init__(self):
		self.msg_handlers: MsgIo = []
		self.state = None

	def msgio_get(self, key):
		obj = MsgIo(key, self.send)
		if key not in self.msg_handlers:
			self.msg_handlers.append(obj)
			return obj
		return None

	def on_connect(self, loop):
		self.state = asyncio.Queue(loop=loop)

	def on_disconnect(self):
		pass

	async def on_recv(self, data):
		d = json.loads(data)
		for key_req in d.keys():
			for h in self.msg_handlers:
				if h.can_key(key_req):
					await h.on_recv(d)

	async def on_send(self):
		return await self.state.get()

	async def send(self, data):
		await self.state.put(data)