/**
 * webrtc page script
 *
 * Author: Peter Harpending <peterharpending@qpq.swiss>
 * Date: 2026-02-04
 * Copyright: Copyright (c) 2026 QPQ AG
 *
 * Reference: https://git.qpq.swiss/QPQ-AG/research-megadoc/src/commit/c7c4592d4b21ad120145ef63334471a1a7ec1e60/paste/2026-02/grok-webrtc.html
 *
 * @module
 */

main();

async function
main
    ()
    : Promise<void>
{
    // start websocket immediately
    let ws = new WebSocket('/ws/webrtc');

    // grab document elements
    let init      = document.getElementById('init')      as HTMLDivElement;
    let roster    = document.getElementById('roster')    as HTMLDivElement;
    let roster_ul = document.getElementById('roster-ul') as HTMLUListElement;
    let whoami    = document.getElementById('whoami')    as HTMLHeadingElement;

    let init_name = document.getElementById('init-name') as HTMLInputElement;
    let init_join = document.getElementById('init-join') as HTMLButtonElement;

    // handle button click
    init_join.addEventListener('click',
        function() {
            handle_join(init, init_name, roster, ws);
        }
    );

    // handle message from ws
    ws.onopen    = function(e) { console.log('ws open:', e); };
    ws.onclose   = function(e) { console.warn('ws closed:', e); };
    ws.onerror   = function(e) { console.error('ws error:', e); };
    ws.onmessage =
        function(e) {
            // console.log('ws message:', e.data);
            let message = JSON.parse(e.data) as ws_msg;
            handle_ws_msg(message, roster_ul, whoami);
        };
}

type ws_msg = ["username", string]
            | ["users", Array<string>];

function
handle_ws_msg
    (message   : ws_msg,
     roster_ul : HTMLUListElement,
     whoami    : HTMLHeadingElement)
    : void
{
    switch(message[0]) {
        case "username":
            whoami.innerText = 'Whoami: ' + message[1];
            break;
        case "users":
            for (let uname of message[1]) {
                let thisli = document.createElement('li');
                thisli.innerText = uname;
                roster_ul.appendChild(thisli);
            }
            break;
    }

}



async function
handle_join
    (init      : HTMLDivElement,
     init_name : HTMLInputElement,
     peers     : HTMLDivElement,
     ws        : WebSocket)
    : Promise<void>
{
    console.log('connecting...');
    let user_name: string = init_name.value.trim();
    console.log('username:', user_name);

    ws_send_json(ws, ['username', user_name]);

    init.hidden = true;
    peers.hidden = false;
}


function
ws_send_json
    (ws : WebSocket,
     x  : any)
    : void
{
    let s: string = JSON.stringify(x, undefined, 4);
    console.log('sending:\n', s);

    ws.send(s);
}