'use strict';

const assert=require('assert/strict');

async function connectRealtime(base,session,{timeout=4000}={}){
  assert(session?.playerId&&session?.token,'Realtime session is required');
  const url=base.replace(/^http/,'ws')+'/api/realtime';
  const socket=new WebSocket(url);
  const queue=[];
  const waiters=[];
  let closed=false;
  function dispatch(message){
    for(let index=0;index<waiters.length;index++){
      const waiter=waiters[index];
      if(waiter.predicate(message)){
        waiters.splice(index,1);clearTimeout(waiter.timer);waiter.resolve(message);return;
      }
    }
    queue.push(message);
  }
  socket.addEventListener('message',event=>{
    try{dispatch(JSON.parse(String(event.data)))}catch(error){dispatch({type:'test-parse-error',error})}
  });
  socket.addEventListener('close',()=>{closed=true;for(const waiter of waiters.splice(0)){clearTimeout(waiter.timer);waiter.reject(new Error('Realtime socket closed'))}});
  await new Promise((resolve,reject)=>{
    const timer=setTimeout(()=>reject(new Error('Realtime socket open timed out')),timeout);
    socket.addEventListener('open',()=>{clearTimeout(timer);resolve()},{once:true});
    socket.addEventListener('error',()=>{clearTimeout(timer);reject(new Error('Realtime socket failed'))},{once:true});
  });
  socket.send(JSON.stringify({type:'hello',playerId:session.playerId,token:session.token}));
  async function waitFor(predicateOrType,waitTimeout=timeout){
    const predicate=typeof predicateOrType==='function'?predicateOrType:message=>message?.type===predicateOrType;
    const found=queue.findIndex(predicate);
    if(found>=0)return queue.splice(found,1)[0];
    if(closed)throw new Error('Realtime socket is closed');
    return new Promise((resolve,reject)=>{
      const waiter={predicate,resolve,reject,timer:null};
      waiter.timer=setTimeout(()=>{const index=waiters.indexOf(waiter);if(index>=0)waiters.splice(index,1);reject(new Error('Realtime message timed out'))},waitTimeout);
      waiters.push(waiter);
    });
  }
  const ready=await waitFor('ready');
  return{
    socket,ready,
    send(message){socket.send(JSON.stringify(message))},
    waitFor,
    close(){try{socket.close()}catch(_){}},
    queued:queue
  };
}

module.exports={connectRealtime};