import { randomInt } from "./deps.ts";

const SERVER_VERSION = "0.1.0";
// TODO: version comparison

type ID = string;

// app state
const allLobbies = new Map<ID, Lobby>();
const allClients = new Map<ID, Client>();

interface DataMessage {
  type: string;
}

type ServerData = Record<string, string | number | symbol> | string;
type Message = string | DataMessage;

const broadcast = (message: Message) =>
  allClients.forEach((client) => client.send(message));

const buildMessage = (
  type: string,
  data: ServerData | ServerData[],
) =>
  Object.assign(
    { type },
    Array.isArray(data)
      ? { data }
      : (typeof data === "object" ? data : { data }),
  );

class Client {
  id: ID;
  name: string;
  socket: WebSocket;
  lobby: Lobby | null;

  constructor(socket: WebSocket) {
    this.id = crypto.randomUUID();
    this.socket = socket;
    this.name = "Client";
    this.lobby = null;

    this.send(buildMessage("your-id", this.id));

    console.log(this);
    allClients.set(this.id, this);
  }

  isConnected() {
    return this.socket.readyState == WebSocket.OPEN;
  }

  remove() {
    this.lobbyLeave();
    if (this.isConnected()) {
      this.socket.close();
    }
    allClients.delete(this.id);
  }

  send(message: Message) {
    try {
      if (this.isConnected()) {
        this.socket.send(
          typeof message === "object"
            ? ("json:" + JSON.stringify(message))
            : message,
        );
      }
    } catch (e) {
      console.error(
        `Failed to send on socket ${this.socket} to client ${this.id}. Disconnecting and removing...`,
      );
    }
  }

  clientList() {
    if (!this.lobby) return;
    const netClients: { id: ID; name: string }[] = [];
    this.lobby.clients.forEach(({ id, name }) => netClients.push({ id, name }));
    // TODO: chunk async?
    this.send(buildMessage("peer_list", netClients));
  }

  lobbyList() {
    const netLobbies: { id: ID; name: string }[] = [];
    allLobbies.forEach(({ id, name }) => netLobbies.push({ id, name }));
    // TODO: chunk async?
    this.send(buildMessage("lobby_list", netLobbies));
  }

  lobbyNew({ id, name }: Lobby) {
    // if the client is already in a lobby, we don't care about new lobbies
    if (this.lobby) return;
    this.send(buildMessage("lobby_new", { id, name }));
  }

  lobbyDelete({ id }: Lobby) {
    if (this.lobby) return;
    this.send(buildMessage("lobby_delete", { id }));
  }

  lobbyCreate() {
    if (this.lobby) {
      this.send(
        `[info] cannot create lobby (already in lobby ${this.lobby.id})`,
      );
      return;
    }
    new Lobby(this);
  }

  lobbyJoin(lobby: Lobby) {
    if (this.lobby) {
      this.send(`[info] cannot join lobby (already in lobby ${this.lobby.id})`);
      return;
    }
    this.lobby = lobby;
    this.send(buildMessage("lobby_joined", { id: lobby.id }));
    lobby.addClient(this);
  }

  lobbyLeave() {
    const leavingLobby = this.lobby;
    if (!leavingLobby) {
      this.send(`[info] cannot leave lobby (not in a lobby)`);
      return;
    }
    this.lobby = null;
    if (this.isConnected()) {
      this.send(buildMessage("lobby_left", { id: leavingLobby.id }));
    }
    leavingLobby.removeClient(this);
  }
}

class Lobby {
  id: ID;
  name: string;
  clients: Map<ID, Client>;
  hostClientId: ID;

  constructor(host: Client, name?: string) {
    this.id = crypto.randomUUID();
    this.hostClientId = host.id;
    this.clients = new Map<ID, Client>();
    this.name = name || this.id;

    allLobbies.set(this.id, this);
    host.lobbyJoin(this);
    allClients.forEach((client) => client.lobbyNew(this));
  }

  remove() {
    allClients.forEach((client) => client.lobbyDelete(this));
    this.clients.forEach((client) => {
      client.lobbyLeave();
    });
    allLobbies.delete(this.id);
  }

  broadcast(message: Message) {
    this.clients.forEach((client) => client.send(message));
  }

  addClient(client: Client) {
    this.clients.set(client.id, client);
    this.broadcast(
      buildMessage("peer_joined", { id: client.id, name: client.name }),
    );
  }

  removeClient({ id }: Client) {
    this.clients.delete(id);
    this.broadcast(buildMessage("peer_left", { id }));
    if (id === this.hostClientId) {
      console.warn("Host left!");
      this.remove();
    }
  }
}

// events
function onMessage(client: Client, ev: MessageEvent) {
  // TODO: log who from?
  console.log("Client Message Received", ev.data);
  if (ev.data === "lobby_create") client.lobbyCreate();
  if (ev.data === "lobby_leave") client.lobbyLeave();
  if (ev.data === "request_lobby_list") client.lobbyList();
  if (ev.data === "request_peer_list") client.clientList();
  if (ev.data.startsWith("lobby_join:")) {
    const id = ev.data.substr(11);
    const lobby = allLobbies.get(id);
    if (lobby) client.lobbyJoin(lobby);
    else client.send(`[info] could not find lobby ${id}`);
  }
}

function onSocketOpen(_client: Client, _ev: Event) {
  console.log("New Client");
}

function onClientLeave(client: Client) {
  client.remove();
}

function onSocketClose(client: Client, _ev: Event) {
  console.log("Client Close");
  onClientLeave(client);
}

function onSocketError(client: Client, _ev: Event) {
  console.log("Client Error");
  onClientLeave(client);
}

const PORT = parseInt(Deno.env.get("PORT") || "80");
console.log("Listening on port", PORT);
const listener = Deno.listen({ port: PORT });
for await (const conn of listener) {
  // console.debug("Connection received:", conn);
  (async () => {
    const server = Deno.serveHttp(conn);
    for await (const { respondWith, request } of server) {
      // console.debug("HTTP Request Received", request);
      try {
        console.warn(JSON.stringify([allClients, allLobbies]));
        const { socket, response } = Deno.upgradeWebSocket(request);
        const client = new Client(socket);
        socket.onmessage = (ev) => onMessage(client, ev);
        socket.onopen = (ev) => onSocketOpen(client, ev);
        socket.onclose = (ev) => onSocketClose(client, ev);
        socket.onerror = (ev) => onSocketError(client, ev);
        respondWith(response);
      } catch (e) {
        console.log("Could not add client for unhandled reason:", e);
        respondWith(
          new Response("400 Bad Request", {
            status: 400,
            headers: { "content-type": "text/html" },
          }),
        );
      }
    }
  })();
}

/*
function peerCreatesLobby(peer: Peer, lobbyName: string) {
  // TODO: ensure we can create a lobby
  lobbies.add({
  })
}
  */

/*
function peerJoinsLobby(peer: Peer, lobby: Lobby) {
      lobbyName = randomSecret();
      lobbies.set(lobbyName, new Lobby(lobbyName, this.id));
      console.log(`Peer ${this.id} created lobby ${lobbyName}`);
      console.log(`Open lobbies: ${lobbies.size}`);
    }
    const lobby = lobbies.get(lobbyName);
    if (!lobby) throw new ProtoError(4000, STR_LOBBY_DOES_NOT_EXIST);
    if (lobby.sealed) throw new ProtoError(4000, STR_LOBBY_IS_SEALED);
    this.lobby = lobbyName;
    console.log(
      `Peer ${this.id} joining lobby ${lobbyName} ` +
        `with ${lobby.peers.length} peers`,
    );
    lobby.join(this);
    this.ws.send(`J: ${lobbyName}\n`);
  }
  // TODO: ensure peer not already in a lobby
  const assigned = this.getPeerId(peer);
  peer.ws.send(`I: ${assigned}\n`);
  this.peers.forEach((p) => {
    p.ws.send(`N: ${assigned}\n`);
    peer.ws.send(`N: ${this.getPeerId(p)}\n`);
  });
  this.peers.push(peer);
}
  */

/*
function peerLeavesLobby(peer: Peer) {
  const idx = this.peers.findIndex((p) => peer === p);
  if (idx === -1) return false;
  const assigned = this.getPeerId(peer);
  const close = assigned === 1;
  this.peers.forEach((p) => {
    try {
      // room host disconnected
      if (close) p.ws.close(4000, STR_HOST_DISCONNECTED);
      // notify peers
      else p.ws.send(`D: ${assigned}\n`);
    } catch (e) {
      console.error(`Error when leaving: ${e}`);
    }
  });
  this.peers.splice(idx, 1);
  if (close && this.closeTimer >= 0) {
    // we are closing already.
    clearTimeout(this.closeTimer);
    this.closeTimer = -1;
  }
  return close;
}
  */

/*
function graduateLobby(lobby: Lobby) {
    // only host can seal
    if (peer.id !== this.host) {
      throw new ProtoError(4000, STR_ONLY_HOST_CAN_SEAL);
    }
    this.sealed = true;
    this.peers.forEach((p) => {
      p.ws.send("S: \n");
    });
    console.log(
      `Peer ${peer.id} sealed lobby ${this.name} ` +
        `with ${this.peers.length} peers`,
    );
    this.closeTimer = setTimeout(() => {
      // close peer connection to host (and thus the lobby)
      this.peers.forEach((p) => {
        p.ws.close(1000, STR_SEAL_COMPLETE);
      });
    }, SEAL_CLOSE_TIMEOUT);
}

}
  */

/*
function parseMsg(peer: Peer, msg: string) {
  // TODO: modify this?
  // O: Client is sending an offer.
  // A: Client is sending an answer.
  // C: Client is sending a candidate.
  let destId = parseInt(cmd.substr(3).trim());
  // Dest is not an ID.
  if (!destId) throw new ProtoError(4000, STR_INVALID_DEST);
  if (destId === 1) destId = lobby.host;
  const dest = lobby.peers.find((p: Peer) => p.id === destId);
  // Dest is not in this room.
  if (!dest) throw new ProtoError(4000, STR_INVALID_DEST);

  function isCmd(what: string) {
    return cmd.startsWith(`${what}: `);
  }
  if (isCmd("O") || isCmd("A") || isCmd("C")) {
    dest.ws.send(cmd[0] + ": " + lobby.getPeerId(peer) + data);
    return;
  }
  throw new ProtoError(4000, STR_INVALID_CMD);
}
  */