document.addEventListener("DOMContentLoaded", function () {
  const input = document.getElementById("command-input");
  // We assume your normal terminal UI is in the element with id "terminal".
  const normalTerminal = document.getElementById("terminal");
  let interactiveWS = null;
  let interactiveMode = false;
  const ansi_up = new AnsiUp;

  // Listen for the "start-interactive" command in normal mode.
  input.addEventListener("keydown", function (event) {
    if (!interactiveMode && event.key === "Enter") {
      const command = input.value.trim();
      if (command === "start-interactive") {
        startInteractiveSession();
        input.value = "";
        event.preventDefault();
        return;
      }
      // Otherwise, your normal HTTP submission…
    }
  });

  function startInteractiveSession() {
    // Hide the normal terminal and input.
    normalTerminal.style.display = "none";
    input.style.display = "none";

    // Create a new container for xterm.js.
    const xtermContainer = document.createElement("div");
    xtermContainer.id = "xterm-container";
    xtermContainer.style.width = "100%";
    xtermContainer.style.height = "100vh";
    // Optionally set additional styling (e.g. background color).
    document.body.appendChild(xtermContainer);

    // Initialize xterm.js Terminal.
    const term = new Terminal({
      cursorBlink: true,
      scrollback: 1000,
      theme: {
        background: "#222",
        foreground: "#eee"
      }
    });
    const fitAddon = new FitAddon.FitAddon();
    term.loadAddon(fitAddon);
    term.open(xtermContainer);
    fitAddon.fit();
    term.focus();

    // Establish the WebSocket connection.
    interactiveWS = new WebSocket("ws://" + location.host + "/terminal");
    interactiveWS.binaryType = "arraybuffer";

    interactiveWS.onmessage = function (event) {
      const text = new TextDecoder("utf-8").decode(event.data);
      term.write(text);
    };

    interactiveWS.onclose = function () {
      interactiveMode = false;
      term.write("\r\n--- Interactive session ended ---\r\n");
      // Remove the xterm container.
      if (xtermContainer.parentNode) {
        xtermContainer.parentNode.removeChild(xtermContainer);
      }
      // Restore the normal terminal UI.
      normalTerminal.style.display = "block";
      input.style.display = "block";
      input.focus();
    };

    interactiveWS.onerror = function (err) {
      term.write("\r\n--- Error in interactive session ---\r\n");
      console.error("Interactive WS error:", err);
      interactiveMode = false;
      if (xtermContainer.parentNode) {
        xtermContainer.parentNode.removeChild(xtermContainer);
      }
      normalTerminal.style.display = "block";
      input.style.display = "block";
    };

    // When the user types in xterm, send the data to the server.
    term.onData(function (data) {
      // If the user presses Ctrl+D (ASCII 4), exit the session.
      if (data === "\x04") {
        term.write("\r\n--- Exiting interactive session ---\r\n");
        interactiveWS.close();
      } else {
        interactiveWS.send(data);
      }
    });

    interactiveMode = true;
  }
});