let sshTerm = null;
let sshFit = null;
let sshWS = null;
let sshResizeTimer = null;

function initPage8() {
  const el = document.getElementById("ssh-terminal");

  if (!el || sshTerm) {
    return;
  }

  sshTerm = new Terminal({
    cursorBlink: true,
    scrollback: 2000,
    fontSize: 14,
    convertEol: true,
    theme: {
      background: "#111111"
    }
  });

  sshFit = new FitAddon.FitAddon();
  sshTerm.loadAddon(sshFit);
  sshTerm.open(el);
  sshTerm.focus();

  connectSSH();

  sshTerm.onData(data => {
    if (sshWS?.readyState === WebSocket.OPEN) {
      sshWS.send(JSON.stringify({
        type: "input",
        data: data
      }));
    }
  });

  window.addEventListener("resize", resizeSSH);

  resizeSSH();
}

function connectSSH() {
  sshWS = new WebSocket(
    "ws://" + location.host + "/api/ssh/ws"
  );

  sshWS.onopen = resizeSSH;

  sshWS.onmessage = e => {
    sshTerm?.write(e.data);
  };

  sshWS.onclose = () => {
    sshWS = null;
    sshTerm.write(
        "\r\n\x1b[33m[Connection closed]\x1b[0m\r\n"
    );
  };
}

function resizeSSH() {
  if (!sshFit || !sshTerm) {
    return;
  }

  clearTimeout(sshResizeTimer);

  sshResizeTimer = setTimeout(() => {

    sshFit.fit();

    if (sshWS?.readyState === WebSocket.OPEN) {
      sshWS.send(JSON.stringify({
        type: "resize",
        cols: sshTerm.cols,
        rows: sshTerm.rows
      }));
    }

  }, 100);
}

function exitPage8() {
  window.removeEventListener(
    "resize",
    resizeSSH
  );

  clearTimeout(sshResizeTimer);

  sshWS?.close();
  sshWS = null;

  sshTerm?.dispose();
  sshTerm = null;

  sshFit = null;
}