#!/usr/bin/env -S deno run -A

import { BufReader, readLines } from "https://deno.land/std/io/mod.ts";
import { serve } from "https://deno.land/std/http/server.ts";
import { acceptWebSocket, WebSocket, isWebSocketPingEvent, isWebSocketCloseEvent } from "https://deno.land/std/ws/mod.ts"
import { v4 } from 'https://deno.land/std/uuid/mod.ts';

let enc = new TextEncoder();
let dec = new TextDecoder();

const WS = new Map<string, WebSocket>()

function broadcast(message: string) {
  WS.forEach((ws)=>{
    ws.send(message);
  });
}

async function handleWs(ws: WebSocket) {
  const uid = v4.generate();
  WS.set(uid, ws);
  console.log('ws connected', uid);
  for await (const event of ws) {
    if (typeof event === 'string') {
      let msg = event;
      // console.log(event);
      broadcast(msg);
    }
    if (event instanceof Uint8Array){
      let msg = dec.decode(event);
      // console.log(dec.decode(event))
      broadcast(msg);
    }
    if (isWebSocketPingEvent(event)){
      console.log('ping', event)
    }
    if (isWebSocketCloseEvent(event)){
      console.log('close', event)
      break
    }
  }
  console.log('bye')
  WS.delete(uid);
}

for await (const req of serve({port: 8080})) {
  // req.respond({body: "Hello World!"});
  console.log(req);
  if (req.headers.get("upgrade") == "websocket") {
    const { conn, r: bufReader, w: bufWriter, headers } = req;
    acceptWebSocket({
      conn,
      bufReader,
      bufWriter,
      headers,
    }).then(handleWs)
  }
}

let ln = Deno.listen({hostname: "0.0.0.0", port: 8080, transport: "tcp"});
let addr = ln.addr as Deno.NetAddr;
console.log(`listening on ${addr.hostname}:${addr.port}`);

for (var id = 0; id < 10; id ++) {
  let conn = await ln.accept();
  let addr = conn.remoteAddr as Deno.NetAddr;
  console.log(`client[${id}] connected from ${addr.hostname}:${addr.port}`);
  readclose(conn, id);
  write(conn, id);
}

async function readclose(conn: Deno.Reader | Deno.Closer, id: number){
  let scanner = new BufReader(conn as Deno.Reader);
  for (;;) {
    try {
      let line = await scanner.readString('\n');
      if (line == null) {
        console.log(`client[${id}] disconnected: read: EOF`);
        break;
      }
      console.log(`client[${id}]: ${line}`);
    }
    catch (e) {
      console.log(`client[${id}] connected: read: ${e.message}`);
      break;
    }
  }
  (conn as Deno.Closer).close();
}

async function write(conn: Deno.Writer, id: number){
  for (;;) {
    let msg = `client[${id}]: stf\n`;
    let buf = enc.encode(msg);
    try {
      await conn.write(buf);
    }
    catch (e) {
      console.log(`client[${id}] disconnected: write: ${e.message}`);
      break;
    }
    await delay(1000);
  }
}

function delay(ms: number) {
    return new Promise( resolve => setTimeout(resolve, ms) );
}