const WebSocket = require("ws");

const PORT = process.env.PORT || 3000;
const wss = new WebSocket.Server({ port: PORT }); // init server asap

const { putVar, getVar } = require("@gd-com/utils");
const { command } = require("./pg");

const HEADERS = {
  relay: "R",
  joinrequest: "J",
  hostrequest: "H",
  stopgame: "K",
  ping: "P",
  signal: "S",
  create_user: "C",
  signin: ">",
};

// { gamecode: {clients: [], ids: []}}
let games = {};

function str_obj(obj) {
  return JSON.stringify(obj, null, 0);
}

function send_packet(data, header, client) {
  const packet = putVar({ data: data, header: header });
  client.send(packet);
}

function send_group_packet(data, header, clients) {
  clients.forEach((client) => {
    send_packet(data, header, client);
  });
}

const interval = setInterval(function ping() {
  function cleanup_games() {
    const keys = Object.keys(games);
    keys.forEach((key) => {
      {
        let value = games[key].clients;
        value.forEach((client) => {
          if (client.is_alive === false) {
            value.splice(value.indexOf(client), 1);
            console.log("removed dead client from " + key);
          } else client.is_alive = false; // becomes true on next ping
          if (games[key].clients.length === 0) {
            delete games[key];
            console.log(`dead game: ${key} deleted`);
          }
        });
      }
    });
  }
  cleanup_games();
}, 5000);

wss.on("close", function close() {
  clearInterval(interval);
});

console.log(`Server started on port ${PORT}`);
wss.on("connection", (ws, req) => {
  console.log(`client connected (${req.socket.remoteAddress})`);
  ws.is_alive = true;

  // on message recieved
  ws.on("message", (message) => {
    let recieve = getVar(Buffer.from(message)).value;
    let data = recieve.data;
    let header = recieve.header;
    if (header) {
      switch (header) {
        case HEADERS.relay:
          dual_relay(data, ws);
          break;
        case HEADERS.joinrequest:
          handle_joinrequest(data, ws);
          break;
        case HEADERS.hostrequest:
          handle_hostrequest(data, ws);
          break;
        case HEADERS.stopgame:
          handle_stop(data, ws);
          break;
        case HEADERS.ping:
          ws.is_alive = true;
          break;
        case HEADERS.signal:
          signal_other(data, ws);
          break;
        case HEADERS.create_user:
          signup(data, ws);
          break;
        case HEADERS.signin:
          signin(data, ws);
          break;
        default:
          console.log(`header ${header} unknown`);
          break;
      }
    }
  });
});

async function get_propertys(name) {
  const c = `SELECT * FROM users WHERE name = '${name}';`;
  const result = await command(c);
  return result.rows[0] ? result.rows[0] : undefined;
}

async function signin(data, ws) {
  const c = `SELECT * FROM users WHERE name = '${data.name}' AND password = '${data.password}';`;
  const res = await command(c);
  if (res.rows[0]) {
    const packet = { id: res.rows[0].id, country: res.rows[0].country };
    send_packet(packet, HEADERS.signin, ws);
  } else {
    send_packet("NO", HEADERS.signin, ws);
  }
}

async function signup(data, ws) {
  console.log("attempting to create user");
  const res = await get_propertys(data.name);
  if (res) {
    send_packet("err: user already exists", HEADERS.create_user, ws);
    console.error("user already exists");
    return; // if existing, send err
  }

  async function init_user() {
    const c = `INSERT INTO users (name, country, password) VALUES ('${data.name}', '${data.country}',  '${data.password}') RETURNING id;`;
    const res = await command(c);
    console.log(`created user sucessully! (${c})`);
    return res.rows[0].id; // return the uuid
  }
  let id;
  try {
    id = await init_user();
  } catch (e) {
    const packet = `err: could not create user(${e.stack})`;
    send_packet(packet, HEADERS.create_user, ws);
    console.error(e.stack);
    return;
  }
  send_packet(id, HEADERS.create_user, ws);
}

function handle_joinrequest(data, ws) {
  function done(id = true) {
    send_packet("Y", HEADERS.joinrequest, ws);
    games[data.gamecode].clients.push(ws);
    if (id) games[data.gamecode].ids.push(data.id);
  }
  if (data.gamecode !== undefined && data.id !== undefined) {
    if (games[data.gamecode] !== undefined) {
      if (games[data.gamecode].ids.length < 2) done();
      else {
        if (games[data.gamecode].ids[1] === data.id)
          done(false); // rejoin support :D
        else send_packet("err: game full", HEADERS.joinrequest, ws);
      }
    } else send_packet("err: game does not exist", HEADERS.joinrequest, ws);
  } else
    send_packet("err: gamecode or id not defined", HEADERS.joinrequest, ws);
}

function handle_hostrequest(data, ws) {
  if (data.gamecode !== undefined && data.id !== undefined) {
    console.log("hostrequest: ", data.gamecode);
    if (games[data.gamecode] === undefined) {
      games[data.gamecode] = { clients: [ws], ids: [data.id] };
      send_packet("Y", HEADERS.hostrequest, ws);
      console.log(`game ${data.gamecode} created`);
    } else {
      const err_packet = `err: "${data.gamecode}" already exists`;
      send_packet(err_packet, HEADERS.hostrequest, ws);
    }
  } else
    send_packet("err: gamecode or id not defined", HEADERS.hostrequest, ws);
}

function handle_stop(data, ws) {
  if (data.gamecode in games) {
    if (games[data.gamecode].clients.includes(ws)) {
      console.log("stopgame " + data.gamecode);
      send_group_packet(
        data.reason,
        HEADERS.stopgame,
        games[data.gamecode].clients
      );
      delete games[data.gamecode];
    }
  }
}

// relays to both clients
function dual_relay(data, ws) {
  if (data.gamecode in games) {
    if (games[data.gamecode].clients.includes(ws)) {
      send_group_packet(data, HEADERS.relay, games[data.gamecode].clients);
      console.log(`relaying ${str_obj(data)} to both clients`);
    }
  }
}

// relays to the other client
function signal_other(data, ws) {
  if (data.gamecode in games) {
    let i = games[data.gamecode].clients.indexOf(ws);
    if (i !== -1) {
      let sendto = games[data.gamecode].clients[i ? 0 : 1];
      send_packet(data, HEADERS.signal, sendto);
      console.log(`sending signal ${str_obj(data)}`);
    }
  }
}