import random
import base64
import json
import os
import datetime


def generate_random_id(_s=set()):
    while (new_id := base64.b32encode(bytearray(random.randint(0, 0xFF) for _ in range(10)))[:16].decode().lower()) in _s:
        pass
    _s.add(new_id)
    return new_id


class Model(object):
    class ApiMethod:
        dict = dict()

        def __init__(self, fun):
            self.dict[fun.__name__] = fun

        def __contains__(self, item):
            return item in self.dict

    def __init__(self, model = {}):
        if "sessions" not in model:
            model["sessions"] = []
        if "clients" not in model:
            model["clients"] = []
        if "items" not in model:
            model["items"] = []
        self.sockets = {}  # mapping: clientid -> sockets
        self.sessions = { session: Session(model = model["sessions"][session]) for session in model["sessions"] }
        self.clients = { client: Client(model = model["clients"][client]) for client in model["clients"] }
        self.items = { item: Item(model = model["items"][item]) for item in model["items"] }
        self.filename = "tehsession.json"

    def to_json(self):
        model = {
            "sessions": {session: self.sessions[session].to_json() for session in self.sessions },
            "clients": {client: self.clients[client].to_json() for client in self.clients },
            "items": {item: self.items[item].to_json() for item in self.items },
        }
        return model

    @ApiMethod
    async def test_api(self, clientid):
        print(f'test_api {clientid=}')

    @ApiMethod
    async def test_yeet(self, clientid):
        raise Exception('yeet')

    @ApiMethod
    async def change_username(self, clientid, username) -> str:
        self.clients[clientid].name = username

    @ApiMethod
    async def create_session(self, clientid, sessionname) -> str:
        if not sessionname:
            raise Exception(f"Sessionname cant be empty!")
        session = Session(name = sessionname, owner = clientid)
        self.sessions[session.id] = session
        print("create_session was called")

    @ApiMethod
    async def change_sessionname(self, clientid, sessionid, sessionname) -> str:
        if not sessionname:
            raise Exception("Cant be empty!")
        session = self.sessions[sessionid]
        if not (session.owner == clientid):
            raise Exception("Ownly owner can change sessionname")
        session.name = sessionname

    @ApiMethod
    async def create_item(self, clientid, name, description, image): 
        client = self.clients[clientid]
        if not client.session:
            raise Exception("create_item requires the client to be host. But client is in no session")
        session = self.sessions[client.session]
        if (session.owner != client.id):
            raise Exception("create_item requires the client to be host. But client is not the owner")
        if not name:
            raise Exception("create_item requires an item name")
        item = Item(name = name, description = description, image = image)
        self.items[item.id] = item


    @ApiMethod
    async def leave_session(self, clientid):
        client = self.clients[clientid]
        sessionid = client.session
        if sessionid:
            session = self.sessions[sessionid]
            session.clients.remove(clientid)
            self.clients[clientid].session = ""

    @ApiMethod
    async def join_session(self, clientid, sessionid):
        client = self.clients[clientid]
        old_sessionid = client.session
        # leave old session
        if old_sessionid:
            old_session = self.sessions[old_sessionid]
            old_session.clients.remove(clientid)
        session = self.sessions[sessionid]
        client.session = sessionid
        session.clients.append(client.id)

    @ApiMethod
    async def draw(self, clientid):
        await self.send_state(clientid)

    async def send_lobby_view(self, clientid):
        data = {}
        client = self.clients[clientid]

        data["view"] = "lobby"
        data["username"] = client.name
        data["sessions"] = {
                session.id: {
                    "id": session.id,
                    "name": session.name,
                    "owned": session.owner == client.id,
                    } for session in self.sessions.values()
                }
        for socket in self.sockets[clientid]:
            await socket.send_json(data)

    async def send_master_view(self, clientid):
        data = {}
        client = self.clients[clientid]
        session = self.sessions[client.session]

        data["view"] = "master"
        data["username"] = client.name
        data["session"] = session.to_json()
        data["items"] = self.to_json()["items"]

        for socket in self.sockets[clientid]:
            await socket.send_json(data)


    async def send_session_view(self, clientid):
        data = {}
        client = self.clients[clientid]
        session = self.sessions[client.session]

        data["view"] = "session"
        data["username"] = client.name
        data["session"] = session.to_json()

        for socket in self.sockets[clientid]:
            await socket.send_json(data)

    async def send_state(self, clientid):
        # TODO: compute state, send to client
        data = {}
        client = self.clients[clientid]
        session = self.sessions[client.session] if client.session else None
        if session:
            if session.owner == client.id:
                await self.send_master_view(clientid)
            else:
                await self.send_session_view(clientid)
        else:
            await self.send_lobby_view(clientid)

    def save(self):
        with open(self.filename, "w") as f:
            json.dump(self.to_json(), f)

    def exists_client(self, clientid: str) -> bool:
        return clientid in self.clients

    def create_client(self, name="Joe") -> str:
        if not name:
            raise Exception("Username cannot be empty!")
        client = Client()
        client.name = name
        self.clients[client.id] = client
        return client.id

    async def subscribe(self, clientid, socket):
        if not clientid in self.sockets:
            self.sockets[clientid] = []
        self.sockets[clientid].append(socket)
        await self.send_state(clientid)

    def unsubscribe(self, socket):
        for client in self.sockets:
            if socket in self.sockets[client]:
                self.sockets[client].remove(socket)

class Session:

    def __init__(self, model = None, owner = None, name = None):
        if model:
            self.id = model["id"]
            self.name = model["name"]
            self.clients = model["clients"]
            self.owner = model["owner"]
        elif owner and name:
            self.id = generate_random_id()
            self.clients = []
            self.owner = owner
            self.name = name
        else:
            raise Exception("Illegal session constructor")

    def to_json(self):
        model = {
            "id": self.id,
            "name": self.name,
            "clients": self.clients,
            "owner": self.owner,
        }
        return model



class Client:

    def __init__(self, model = None):
        if model:
            self.id = model["id"]
            self.name = model["name"]
            self.session = model["session"]
        else:
            self.id = generate_random_id()
            self.name = "Default Client Name"
            self.session = ""

    def to_json(self):
        model = {
            "id": self.id,
            "name": self.name,
            "session": self.session,
        }
        return model

class Item:

    def __init__(self, model = None, name = None, description = "", image = ""):
        if model:
            self.id = model["id"]
            self.name = model["name"]
            self.description = model["description"]
            self.image = model["image"]
        elif name:
            self.id = generate_random_id()
            self.name = name
            self.description = description
            self.image = image
        else:
            raise Exception("Illegal Item Constructor")

    def to_json(self):
        model = {
            "id": self.id,
            "name": self.name,
            "description": self.description,
            "image": self.image,
        }
        return model