(function () {
  'use strict';

  var term = document.getElementById('term');
  var connStatus = document.getElementById('conn-status');
  var form = document.getElementById('input-bar');
  var input = document.getElementById('cmd');
  var menuBtn = document.getElementById('menu-btn');
  var menuPanel = document.getElementById('menu-panel');
  var deviceSelect = document.getElementById('device-select');
  var hdrDevice = document.getElementById('hdr-device');
  var hdrCallerid = document.getElementById('hdr-callerid');
  var hdrCallid = document.getElementById('hdr-callid');
  var hdrAx25 = document.getElementById('hdr-ax25');
  var hdrConnected = document.getElementById('hdr-connected');

  var wsUrl = window.MAX25_WS_URL;
  var defaults = window.MAX25_SESSION_DEFAULTS || {};
  var ws = null;
  var reconnectTimer = null;
  var reconnectDelayMs = 2000;
  var reconnectAttempt = 0;
  var lineBuf = '';
  var rxLines = [];
  var RX_MAX = 200;
  var waitingReply = false;
  var pendingCmd = null;
  var devices = [];
  var sessionReady = false;
  var bootstrapQueue = [];

  var status = {
    device: '',
    callerid: '',
    callid: '',
    ax25_ui: true,
    connected: false,
    monitor: false,
    stack: ''
  };

  function classifyLine(line) {
    if (!line) {
      return 'ignore';
    }
    if (line === 'OK') {
      return 'ok';
    }
    if (line.indexOf('ERR ') === 0) {
      return 'err';
    }
    if (line.indexOf('STATUS ') === 0) {
      return 'status';
    }
    if (line.indexOf('RX ') === 0) {
      return 'rx';
    }
    if (line.indexOf('EVENT ') === 0) {
      return 'event';
    }
    if (line.indexOf('DEVICE ') === 0) {
      return 'device';
    }
    return 'other';
  }

  function parseKvLine(payload) {
    var out = {};
    var parts = payload.split(' ');
    var i;
    for (i = 0; i < parts.length; i++) {
      var eq = parts[i].indexOf('=');
      if (eq > 0) {
        out[parts[i].slice(0, eq)] = parts[i].slice(eq + 1);
      }
    }
    return out;
  }

  function parseStatus(line) {
    var kv = parseKvLine(line.slice(7));
    if (kv.device !== undefined) {
      status.device = kv.device;
    }
    if (kv.callerid !== undefined) {
      status.callerid = kv.callerid;
    }
    if (kv.callid !== undefined) {
      status.callid = kv.callid;
    }
    if (kv.ax25_ui !== undefined) {
      status.ax25_ui = kv.ax25_ui === 'on';
    }
    if (kv.connected !== undefined) {
      status.connected = kv.connected === 'yes';
    }
    if (kv.stack !== undefined) {
      status.stack = kv.stack;
    }
    updateHeader();
  }

  function parseDeviceLine(line) {
    var kv = parseKvLine(line.slice(7));
    if (!kv.id) {
      return null;
    }
    return {
      id: kv.id,
      hardware: kv.hardware || '',
      serial: kv.serial || '',
      stack: kv.stack || '',
      enabled: kv.enabled || 'yes',
      error: kv.error || '',
      voice: kv.voice || ''
    };
  }

  function validCallsign(value) {
    if (!value) {
      return false;
    }
    var m = /^([A-Z0-9]{1,6})(?:-([0-9]{1,2}))?$/i.exec(value.trim());
    if (!m) {
      return false;
    }
    if (m[2] !== undefined && parseInt(m[2], 10) > 15) {
      return false;
    }
    return true;
  }

  function updateHeader() {
    hdrDevice.textContent = status.device || '-';
    hdrCallerid.textContent = status.callerid || '-';
    hdrCallid.textContent = status.callid || '-';
    hdrAx25.textContent = status.ax25_ui ? 'on' : 'off';
    hdrConnected.textContent = status.connected ? 'yes' : 'no';
  }

  function refreshDeviceSelect() {
    var html = '';
    var i;
    if (devices.length === 0) {
      deviceSelect.innerHTML = '<option value="">—</option>';
      deviceSelect.disabled = true;
      return;
    }
    for (i = 0; i < devices.length; i++) {
      var d = devices[i];
      var sel = d.id === status.device ? ' selected' : '';
      html += '<option value="' + escapeAttr(d.id) + '"' + sel + '>' +
        escapeHtml(d.id) + '</option>';
    }
    deviceSelect.innerHTML = html;
    deviceSelect.disabled = !sessionReady;
  }

  function escapeHtml(s) {
    return String(s)
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;');
  }

  function escapeAttr(s) {
    return escapeHtml(s).replace(/"/g, '&quot;');
  }

  function appendRx(text) {
    var lines = String(text).split('\n');
    var i;
    for (i = 0; i < lines.length; i++) {
      if (lines[i] === '' && i === lines.length - 1) {
        continue;
      }
      rxLines.push(lines[i]);
      if (rxLines.length > RX_MAX) {
        rxLines.shift();
      }
    }
    term.textContent = rxLines.join('\n') + (rxLines.length ? '\n' : '');
    term.scrollTop = term.scrollHeight;
  }

  function setConnStatus(s) {
    connStatus.textContent = s;
  }

  function setInputEnabled(enabled) {
    input.disabled = !enabled;
    if (enabled) {
      input.focus();
    }
  }

  function sendRaw(cmd) {
    if (!ws || ws.readyState !== WebSocket.OPEN) {
      return false;
    }
    ws.send(cmd + '\n');
    return true;
  }

  function sendCmd(cmd, label) {
    pendingCmd = label || cmd;
    waitingReply = true;
    return sendRaw(cmd);
  }

  function applyEvent(line) {
    if (line === 'EVENT connected') {
      status.connected = true;
      updateHeader();
      return true;
    }
    if (line === 'EVENT disconnected') {
      status.connected = false;
      updateHeader();
      return true;
    }
    return false;
  }

  var bootstrapped = false;

  function handleLine(line) {
    var kind = classifyLine(line);

    if (kind === 'rx') {
      appendRx(line.slice(3));
      return;
    }

    if (kind === 'event') {
      if (applyEvent(line)) {
        appendRx(line);
      }
      return;
    }

    if (waitingReply) {
      if (kind === 'status') {
        parseStatus(line);
        appendRx('STATUS device=' + (status.device || '-') +
          ' stack=' + (status.stack || '-') +
          ' connected=' + (status.connected ? 'yes' : 'no') +
          ' callerid=' + (status.callerid || '-') +
          ' callid=' + (status.callid || '-'));
        return;
      }
      if (kind === 'device') {
        var dev = parseDeviceLine(line);
        if (dev) {
          devices.push(dev);
        }
        if (pendingCmd === 'GET DEVICES') {
          appendRx(line);
        }
        return;
      }
      if (kind === 'ok') {
        waitingReply = false;
        if (pendingCmd === 'GET DEVICES') {
          refreshDeviceSelect();
        }
        pendingCmd = null;
        if (bootstrapQueue.length > 0) {
          window.setTimeout(runBootstrapStep, 0);
        }
        return;
      }
      if (kind === 'err') {
        waitingReply = false;
        appendRx(line);
        pendingCmd = null;
        if (bootstrapQueue.length > 0) {
          bootstrapQueue = [];
        }
        return;
      }
      return;
    }

    if (kind === 'status') {
      parseStatus(line);
      if (!bootstrapped) {
        bootstrapped = true;
        startBootstrap();
      }
      return;
    }
    if (kind === 'err') {
      appendRx(line);
    }
  }

  function feedText(chunk) {
    lineBuf += chunk;
    var idx;
    while ((idx = lineBuf.indexOf('\n')) >= 0) {
      var line = lineBuf.slice(0, idx);
      lineBuf = lineBuf.slice(idx + 1);
      if (line.endsWith('\r')) {
        line = line.slice(0, -1);
      }
      handleLine(line);
    }
  }

  function queueBootstrap(cmd, label) {
    bootstrapQueue.push({ cmd: cmd, label: label || cmd });
  }

  function runBootstrapStep() {
    if (!sessionReady || waitingReply || bootstrapQueue.length === 0) {
      return;
    }
    var step = bootstrapQueue.shift();
    sendCmd(step.cmd, step.label);
  }

  function startBootstrap() {
    bootstrapQueue = [];
    devices = [];
    refreshDeviceSelect();
    sessionReady = true;

    if (defaults.callerid && defaults.callerid !== status.callerid) {
      queueBootstrap('SET CALLERID ' + defaults.callerid.toUpperCase());
    }
    if (defaults.callid && defaults.callid !== status.callid) {
      queueBootstrap('SET CALLID ' + defaults.callid.toUpperCase());
    }
    queueBootstrap('SET AX25_UI ' + (defaults.ax25_ui !== false ? 'on' : 'off'));
    if (defaults.device) {
      queueBootstrap('SET DEVICE ' + defaults.device);
    }
    queueBootstrap('GET DEVICES', 'GET DEVICES');
    if (defaults.connect_on_start !== false) {
      queueBootstrap('CONNECT');
    }
    queueBootstrap('GET STATUS');

    sessionReady = true;
    runBootstrapStep();
  }

  function fetchDevices() {
    devices = [];
    sendCmd('GET DEVICES', 'GET DEVICES');
  }

  function setDevice(id) {
    if (!id) {
      return;
    }
    var known = false;
    var i;
    for (i = 0; i < devices.length; i++) {
      if (devices[i].id === id) {
        known = true;
        break;
      }
    }
    if (devices.length === 0) {
      appendRx('ERR device list empty — run /devices first');
      return;
    }
    if (!known) {
      appendRx('ERR unknown device (not in max25d): ' + id);
      return;
    }
    sendCmd('SET DEVICE ' + id);
    window.setTimeout(function () {
      sendCmd('GET STATUS');
    }, 50);
  }

  function slashHelp() {
    appendRx(
      '-- MAX25 browser commands (F10 menu equivalent) --\n' +
      '/callerid [id]   /callid [id]   /status\n' +
      '/send <text>     /monitor [on|off|toggle]\n' +
      '/connect         /disconnect\n' +
      '/device <id>     /devices\n' +
      '/ax25_ui on|off  /help\n' +
      'Plain text (no /) is sent as SEND (like max25-terminal Enter).'
    );
  }

  function handleSlash(line) {
    var parts = line.slice(1).trim().split(/\s+/);
    var cmd = (parts[0] || '').toLowerCase();
    var arg = parts.slice(1).join(' ');

    menuPanel.classList.remove('open');
    menuBtn.setAttribute('aria-expanded', 'false');

    if (cmd === 'help' || cmd === 'menu') {
      slashHelp();
      return;
    }
    if (cmd === 'callerid' || cmd === 'caller') {
      if (arg) {
        if (!validCallsign(arg)) {
          appendRx('ERR invalid CALLERID');
          return;
        }
        sendCmd('SET CALLERID ' + arg.toUpperCase());
      } else {
        var v = window.prompt('CALLERID', status.callerid || defaults.callerid || '');
        if (v && validCallsign(v)) {
          sendCmd('SET CALLERID ' + v.toUpperCase());
        }
      }
      return;
    }
    if (cmd === 'callid' || cmd === 'call') {
      if (arg) {
        if (!validCallsign(arg)) {
          appendRx('ERR invalid CALLID');
          return;
        }
        sendCmd('SET CALLID ' + arg.toUpperCase());
      } else {
        var w = window.prompt('CALLID', status.callid || defaults.callid || '');
        if (w && validCallsign(w)) {
          sendCmd('SET CALLID ' + w.toUpperCase());
        }
      }
      return;
    }
    if (cmd === 'status') {
      sendCmd('GET STATUS');
      return;
    }
    if (cmd === 'send') {
      if (!arg) {
        arg = window.prompt('Send line', '');
      }
      if (arg) {
        sendCmd('SEND ' + arg);
      }
      return;
    }
    if (cmd === 'monitor') {
      var on;
      if (arg === 'on' || arg === 'yes' || arg === '1') {
        on = true;
      } else if (arg === 'off' || arg === 'no' || arg === '0') {
        on = false;
      } else {
        on = !status.monitor;
      }
      status.monitor = on;
      sendCmd('MONITOR ' + (on ? 'on' : 'off'));
      appendRx(on ? 'MONITOR on' : 'MONITOR off');
      return;
    }
    if (cmd === 'connect') {
      sendCmd(status.connected ? 'DISCONNECT' : 'CONNECT');
      return;
    }
    if (cmd === 'disconnect') {
      sendCmd('DISCONNECT');
      return;
    }
    if (cmd === 'devices') {
      fetchDevices();
      return;
    }
    if (cmd === 'device') {
      if (!arg) {
        fetchDevices();
        appendRx('Pick device from dropdown or: /device <id>');
        return;
      }
      setDevice(arg);
      return;
    }
    if (cmd === 'ax25_ui' || cmd === 'ax25-ui') {
      var flag = (arg || '').toLowerCase();
      if (flag !== 'on' && flag !== 'off') {
        flag = status.ax25_ui ? 'off' : 'on';
      }
      sendCmd('SET AX25_UI ' + flag);
      return;
    }
    if (cmd === 'quit' || cmd === 'exit') {
      if (ws) {
        ws.close();
      }
      return;
    }
    appendRx('ERR unknown /command — try /help');
  }

  function scheduleReconnect() {
    if (reconnectTimer) {
      return;
    }
    reconnectAttempt += 1;
    setConnStatus('reconnecting in ' + (reconnectDelayMs / 1000) + 's');
    reconnectTimer = window.setTimeout(function () {
      reconnectTimer = null;
      connect();
    }, reconnectDelayMs);
  }

  function connect() {
    setConnStatus('connecting');
    setInputEnabled(false);
    sessionReady = false;
    lineBuf = '';
    ws = new WebSocket(wsUrl);

    ws.onopen = function () {
      reconnectAttempt = 0;
      setConnStatus('connected');
      setInputEnabled(true);
    };

    ws.onmessage = function (ev) {
      feedText(ev.data);
    };

    ws.onclose = function (ev) {
      var reason = ev.reason ? ' (' + ev.reason + ')' : '';
      appendRx('\n[websocket disconnected: code ' + ev.code + reason + ']\n');
      setConnStatus('disconnected: ' + ev.code);
      ws = null;
      sessionReady = false;
      setInputEnabled(false);
      deviceSelect.disabled = true;
      scheduleReconnect();
    };

    ws.onerror = function () {
      setConnStatus('error');
      setInputEnabled(false);
    };
  }

  form.addEventListener('submit', function (ev) {
    ev.preventDefault();
    if (!ws || ws.readyState !== WebSocket.OPEN || waitingReply) {
      return;
    }
    var text = input.value;
    input.value = '';
    if (!text) {
      return;
    }
    if (text.charAt(0) === '/') {
      handleSlash(text);
      return;
    }
    sendCmd('SEND ' + text);
  });

  menuBtn.addEventListener('click', function (ev) {
    ev.stopPropagation();
    var open = menuPanel.classList.toggle('open');
    menuBtn.setAttribute('aria-expanded', open ? 'true' : 'false');
  });

  document.addEventListener('click', function () {
    menuPanel.classList.remove('open');
    menuBtn.setAttribute('aria-expanded', 'false');
  });

  menuPanel.addEventListener('click', function (ev) {
    ev.stopPropagation();
    var btn = ev.target.closest('button[data-action]');
    if (!btn) {
      return;
    }
    var action = btn.getAttribute('data-action');
    if (action === 'callerid') {
      handleSlash('/callerid');
    } else if (action === 'callid') {
      handleSlash('/callid');
    } else if (action === 'status') {
      handleSlash('/status');
    } else if (action === 'send') {
      handleSlash('/send');
    } else if (action === 'monitor') {
      handleSlash('/monitor toggle');
    } else if (action === 'connect') {
      handleSlash('/connect');
    } else if (action === 'devices') {
      handleSlash('/devices');
    } else if (action === 'ax25_ui') {
      handleSlash('/ax25_ui');
    } else if (action === 'help') {
      handleSlash('/help');
    }
  });

  deviceSelect.addEventListener('change', function () {
    if (deviceSelect.value) {
      setDevice(deviceSelect.value);
    }
  });

  updateHeader();
  connect();
})();