import GameServer from './server';
import { ipcRenderer } from 'electron';

let LAST_TOS = "";

export default async function CheckNAcceptTOS(server:GameServer):Promise<boolean>{
  try{
    let thisVersion = await getTOSVersion(server.TOSLink);
    console.log(server.TOSLink,thisVersion);
    LAST_TOS=thisVersion;
    return (localStorage.getItem(server.TOSLink) == thisVersion);

  } catch (err) {
    console.log("TOS check Error",err);
    return true
  }

}

async function getTOSVersion(address:string):Promise<string>{
  // Returns date or if not found the hash of the whole page
  const PageContent = await request(address);
  const date = PageContent.match(/Last Update: \d\d\d\d-\d\d-\d\d/g);
  let hash:string;
  if(!date || date.length > 1){
    hash = HashString(PageContent.replace(/ |\t|\n/g,"").replace(/<.+?>/g, "r")).toString(16);
  } else {
    hash = date[0].replace(/ /g,"");
  }

  return hash;
}

function request(url:string):Promise<string>{
  return new Promise((res, rej)=>{
      var xhr = new XMLHttpRequest();
      xhr.open('GET', url);
      xhr.addEventListener("error", (ev)=>{
        rej(ev);
      });
      xhr.onload = function() {
        if (xhr.status === 200) {
          res(xhr.responseText);
        }
        else {
          rej(new Error(`xhr.status: ${xhr.status} != 200`));
        }
      };
      xhr.send();
  });
}



// Hash function from http://werxltd.com/wp/2010/05/13/javascript-implementation-of-javas-string-hashcode-method/
function HashString (s:string){
	let hash = 0;
	if (s.length == 0) return hash;
	for (let i = 0; i < s.length; i++) {
		let char = s.charCodeAt(i);
		hash = ((hash<<5)-hash)+char;
		hash = hash & hash; // Convert to 32bit integer
	}
	return hash;
}

export function acceptLastTOS(server:GameServer){
  localStorage.setItem(server.TOSLink, LAST_TOS);
}