#!/usr/bin/env node
const http = require("http");
const express = require("express");
const socketio = require("socket.io")

const PORT = (() => {
  if (process.argv.length == 3) {
    return +process.argv[2];
  } else if (process.argv.length == 2) {
    return 8080;
  } else {
    console.log("Usage: server.js [port]");
    process.exit(1);
  }
})();


const app = express();
const server = http.Server(app);
const io = socketio(server);

// gameid -> {pl: [socket]*{1,2}, started: Bool, nextServe: Int, score: [Int, Int]}
const games = new Map();

function genId() {
  for (let i = 0; i < 10; i++) {
    // 2176782336 == 36^6
    const id = ("000000" + (2176782336 * Math.random() | 0).toString(36)).slice(-6);
    if (!games.has(id)) return id;
  }
  return "";
}

function validId(id) {
  return /^[0-9a-z]{6}$/.test(id);
}

app.get("/", (req, res) => {
  const gameid = genId();
  if (gameid == "") {
    res.sendStatus(500);
    return;
  }
  res.redirect("/game/" + gameid);
});

app.param("gameid", (req, res, next, gameid) => {
  if (!validId(gameid)) {
    res.sendStatus(404);
  } else {
    next();
  }
});

app.get("/game/:gameid", (req, res) => {
  res.sendFile(__dirname + "/game.html");
});

const staticFiles = [
  "/game.css",
  "/game.js",
  /^\/snd\//,
];

app.get(staticFiles, (req, res) => {
  res.sendFile(__dirname + req.path);
});

io.on("connection", (conn) => {
  let gameid, gameobj;
  conn.on("open", (id) => {
    console.log("open " + id);
    if (!validId(id)) {
      console.log("  invalid");
      conn.emit("redirect", "/");
      conn.disconnect(true);
      return;
    }
    gameobj = games.get(id);
    if (gameobj != undefined) {
      if (gameobj.pl.length == 1 && !gameobj.started) {
        console.log("  serve");
        gameid = id;
        gameobj.pl.push(conn);
        gameobj.pl[0].emit("join");
        gameobj.pl[0].emit("status", "Get ready...");
        gameobj.pl[1].emit("status", "Get ready...");
        gameobj.pl[0].emit("serve", "left", 0.5, 0.5, true);
        gameobj.pl[1].emit("serve", "right", 0.5, 0.5, true);
        gameobj.started = true;
        setTimeout(() => {
          if (!gameobj || gameobj.pl.length != 2) return;
          gameobj.pl[0].emit("status", "");
          gameobj.pl[1].emit("status", "");
          gameobj.pl[0].emit(gameobj.nextServe == 0 ? "startBall" : "start");
          gameobj.pl[1].emit(gameobj.nextServe == 1 ? "startBall" : "start");
          gameobj.nextServe = 1 - gameobj.nextServe;
        }, 2000);
      } else {
        console.log("  full");
        gameobj = undefined;
        conn.emit("status", "Game full! Opening new game...");
        setTimeout(() => {
          conn.emit("redirect", "/");
          conn.disconnect(true);
        }, 2000);
      }
    } else {
      console.log("  new");
      gameid = id;
      gameobj = {pl: [conn], started: false, nextServe: 0, score: [0, 0]};
      games.set(gameid, gameobj);
      conn.emit("status", "Waiting for other player...");
    }
  });

  conn.on("disconnect", () => {
    if (gameobj == undefined) return;

    console.log("stop " + gameid);

    const newpl = [];
    for (const p of gameobj.pl) {
      if (p != conn) {
        p.emit("stop");
        p.emit("leave");
        p.emit("status", "Other player left.");
        setTimeout(() => {
          p.emit("redirect", "/");
          p.disconnect(true);
        }, 2000);
        newpl.push(p);
      }
    }

    if (newpl.length == 0) {
      console.log("  delete");
      games.delete(gameid);
    } else {
      gameobj.pl = newpl;
    }
  });

  conn.on("padvec", (pos, vel) => {
    if (!gameobj) return;
    for (const p of gameobj.pl) {
      if (p != conn) {
        p.emit("padvec", pos, vel);
      }
    }
  });

  conn.on("ballvec", (x, y, vx, vy) => {
    if (!gameobj) return;
    for (const p of gameobj.pl) {
      if (p != conn) {
        p.emit("ballvec", 1 - x, y, -vx, vy);
      }
    }
  });

  conn.on("bounce", () => {
    if (!gameobj) return;
    for (const p of gameobj.pl) {
      if (p != conn) {
        p.emit("bounce");
      }
    }
  });

  conn.on("ballout", () => {
    if (!gameobj || gameobj.pl.length != 2) return;

    gameobj.pl[0].emit("stop");
    gameobj.pl[1].emit("stop");
    gameobj.pl[0].emit("status", "Ball out!");
    gameobj.pl[1].emit("status", "Ball out!");

    for (let i = 0; i < gameobj.pl.length; i++) {
      if (gameobj.pl[i] != conn) {
        gameobj.score[i]++;
        gameobj.pl[i].emit("othermiss");
      }
    }

    gameobj.pl[0].emit("score", gameobj.score);
    gameobj.pl[1].emit("score", gameobj.score);

    setTimeout(() => {
      if (!gameobj || gameobj.pl.length != 2) return;
      gameobj.pl[0].emit("status", "Get ready...");
      gameobj.pl[1].emit("status", "Get ready...");
      gameobj.pl[0].emit("serve", "left", 0.5, 0.5, false);
      gameobj.pl[1].emit("serve", "right", 0.5, 0.5, false);

      setTimeout(() => {
        if (!gameobj || gameobj.pl.length != 2) return;
        gameobj.pl[0].emit("status", "");
        gameobj.pl[1].emit("status", "");
        gameobj.pl[0].emit(gameobj.nextServe == 0 ? "startBall" : "start");
        gameobj.pl[1].emit(gameobj.nextServe == 1 ? "startBall" : "start");
        gameobj.nextServe = 1 - gameobj.nextServe;
      }, 2000);
    }, 2000);
  });
});

server.listen(PORT, () => console.log("Listening on port " + PORT));