(function() {
  function esc(v) {
    return String(v === undefined || v === null ? '' : v)
      .replace(/&/g, '&')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#39;');
  }

  function short(v, n) {
    if (!v) return '-';
    return v.length > n ? v.slice(0, n) + '...' : v;
  }

  function fmtTime(iso) {
    if (!iso) return '-';
    return iso.replace('T', ' ').replace('Z', ' UTC');
  }

  function timeAgo(iso) {
    if (!iso) return '-';
    var now = Date.now();
    var ts = new Date(iso).getTime();
    if (!isFinite(ts)) return '-';
    var diffSec = Math.max(0, Math.floor((now - ts) / 1000));
    if (diffSec < 10) return 'a few seconds ago';
    if (diffSec < 60) return diffSec + ' seconds ago';
    var diffMin = Math.floor(diffSec / 60);
    if (diffMin < 60) return diffMin === 1 ? 'a minute ago' : diffMin + ' minutes ago';
    var diffHour = Math.floor(diffMin / 60);
    if (diffHour < 24) return diffHour === 1 ? 'an hour ago' : diffHour + ' hours ago';
    var diffDay = Math.floor(diffHour / 24);
    if (diffDay === 1) return 'yesterday';
    if (diffDay < 30) return diffDay + ' days ago';
    var diffMonth = Math.floor(diffDay / 30);
    if (diffMonth < 12) return diffMonth === 1 ? 'a month ago' : diffMonth + ' months ago';
    var diffYear = Math.floor(diffMonth / 12);
    return diffYear === 1 ? 'a year ago' : diffYear + ' years ago';
  }

  function shortAddress(addr) {
    if (!addr) return '-';
    if (addr.length <= 9) return addr;
    return addr.slice(0, 3) + '...' + addr.slice(-3);
  }

  function txLabel(eventType) {
    var map = {
      TRANSFER: 'Transfer',
      REGISTER_KEY: 'Register',
      CREATE_CHANNEL: 'Create Channel',
      ADD_MEMBER: 'Add Member',
      OPEN_PAY_CHAN: 'Open Channel',
      CLOSE_PAY_CHAN: 'Close Channel',
      RELAY_PROOF: 'Relay Proof',
      BIND_WALLET: 'Bind Wallet',
      SLASH: 'Slash',
      HEARTBEAT: 'Heartbeat',
      BLOCK_REWARD: 'Reward'
    };
    return map[eventType] || eventType || 'Transaction';
  }

  function toToken(micro) {
    if (micro === undefined || micro === null) return '-';
    var n = Number(micro);
    if (isNaN(n)) return String(micro);
    return (n / 1000000).toFixed(6) + ' T';
  }

  // Compact token display: 21000000 T → "21M T", 1234 T → "1.23k T"
  function _fmtNum(n) {
    if (n >= 100) return Math.round(n).toString();
    if (n >= 10)  return n.toFixed(1).replace(/\.0$/, '');
    return n.toFixed(2).replace(/\.?0+$/, '');
  }
  function toTokenShort(micro) {
    if (micro === undefined || micro === null) return '-';
    var t = Number(micro) / 1000000;
    if (isNaN(t)) return String(micro);
    if (t >= 1e9) return _fmtNum(t / 1e9) + 'B T';
    if (t >= 1e6) return _fmtNum(t / 1e6) + 'M T';
    if (t >= 1e3) return _fmtNum(t / 1e3) + 'k T';
    if (t >= 0.01) return _fmtNum(t) + ' T';
    var ut = Number(micro);
    if (ut >= 1000) return _fmtNum(ut / 1000) + 'k µT';
    return ut + ' µT';
  }

  function isPubKey(s) {
    return /^[0-9a-fA-F]{64}$/.test(s || '');
  }

  function setStatus(text, cls) {
    var el = document.getElementById('status');
    if (!el) return;
    el.className = 'status' + (cls ? ' ' + cls : '');
    el.textContent = text;
  }

  async function fetchJSON(url) {
    var resp = await fetch(url);
    var json = await resp.json().catch(function() { return {}; });
    if (!resp.ok) {
      throw new Error(json && json.error ? json.error : 'request failed');
    }
    if (json && json.error) {
      throw new Error(json.error);
    }
    return json;
  }

  function q(name) {
    return new URLSearchParams(window.location.search).get(name) || '';
  }

  function navAddress(address) {
    window.location.href = '/address?address=' + encodeURIComponent(address);
  }

  function navTx(id) {
    window.location.href = '/tx?id=' + encodeURIComponent(id);
  }

  function navNode(node) {
    window.location.href = '/node?node=' + encodeURIComponent(node);
  }

  function refreshIcons() {
    if (window.lucide && typeof window.lucide.createIcons === 'function') {
      window.lucide.createIcons();
    }
  }

  // ── SSE live event stream ─────────────────────────────────────────────────
  //
  // connectSSE(handlers) opens a connection to GET /api/events and dispatches
  // events to the supplied handler map, e.g.:
  //
  //   C.connectSSE({
  //     block:        function(data) { ... },
  //     tx:           function(data) { ... },
  //     contract_log: function(data) { ... },
  //     connected:    function()     { /* SSE connection established */ },
  //     error:        function()     { /* connection lost */ },
  //   });
  //
  // Returns the EventSource instance so the caller can close it if needed.
  function connectSSE(handlers) {
    if (!window.EventSource) return null; // browser doesn't support SSE

    var es = new EventSource('/api/events');

    es.addEventListener('open', function() {
      if (handlers.connected) handlers.connected();
    });

    es.addEventListener('error', function() {
      if (handlers.error) handlers.error();
    });

    ['block', 'tx', 'contract_log'].forEach(function(type) {
      if (!handlers[type]) return;
      es.addEventListener(type, function(e) {
        try {
          var data = JSON.parse(e.data);
          handlers[type](data);
        } catch (_) {}
      });
    });

    return es;
  }

  window.ExplorerCommon = {
    esc: esc,
    short: short,
    fmtTime: fmtTime,
    timeAgo: timeAgo,
    shortAddress: shortAddress,
    txLabel: txLabel,
    toToken: toToken,
    toTokenShort: toTokenShort,
    isPubKey: isPubKey,
    setStatus: setStatus,
    fetchJSON: fetchJSON,
    q: q,
    navAddress: navAddress,
    navTx: navTx,
    navNode: navNode,
    refreshIcons: refreshIcons,
    connectSSE: connectSSE
  };

  refreshIcons();
})();