import websockets
import json

from storage import Storage

class Routes():
    __connections = set()
    __storages = {}

    def __init__(self):
        self.__commands = {
                "add": self._add_entity,
                "get": self._get_entity,
                "mod": self._mod_entity,
                "del": self._del_entity,
                "describe": self._describe
            }

    def __storage(self, name):
        if not name in self.__storages:
            self.__storages[name] = Storage(name)
        return self.__storages[name]

    def __get_entity(self, event):
        return event.get("entity", None)

    def __get_data(self, event):
        return event.get("data", {})

    def __get_event(self, name, event, data):
        return { "entity": name, "event": event, "data": data }

    async def _add_entity(self, websocket, event):
        name = self.__get_entity(event)
        data = self.__get_data(event)
        if name and data:
            self.__storage(name).create(data)
            await self._broadcast(websocket, self.__get_event(name, "created", data))

    async def _get_entity(self, websocket, event):
        name = self.__get_entity(event)
        ts = self.__get_data(event).get("ts", 0)
        data = self.__storage(name).read(ts)
        await websocket.send(json.dumps(self.__get_event(name, "received", data )))

    async def _mod_entity(self, websocket, event):
        name = self.__get_entity(event)
        data = self.__get_data(event)
        if name and data:
            self.__storage(name).update(data)
            await self._broadcast(websocket, self.__get_event(name, "modified", data))

    async def _del_entity(self, websocket, event):
        name = self.__get_entity(event)
        entity_id = self.__get_data(event).get("id", None)
        if self.__storage(name).delete(entity_id):
            await self._broadcast(websocket, self.__get_event(name, "deleted", entity_id ))

    async def _describe(self, websocket, event):
        data = {}
        for connection in self.__connections:
            user_id = connection.user["id"]
            data[user_id] = data[user_id] + 1 if user_id in data else 1
        await websocket.send(json.dumps(self.__get_event("connections", "described", data)))

    async def _broadcast(self, _, event):
        websockets.broadcast(self.__connections, json.dumps(event))

    async def add_connection(self, connection):
        self.__connections.add(connection)
        await self._broadcast(connection, self.__get_event("users", "connected", connection.user))

    async def remove_connection(self, connection):
        self.__connections.remove(connection)
        await self._broadcast(connection, self.__get_event("users", "disconnected", connection.user))

    async def call(self, command, websocket, event):
        handler = self.__commands.get(command, self._broadcast)
        await handler(websocket, event)

    def users(self):
        return self.__storage("users").read()