/* Dashboard widget cells: say when a cell is loading, when it could not load,
   and how fresh what it shows is (#5208).

   Each .dash-cell-body is an htmx target with a request deadline
   (hx-request timeout), so every fetch ends in a swap or one of the error
   events below. A cell that polls keeps polling through htmx's own `every`
   trigger; a cell that loads once is retried here, re-armed from the failure
   handler of each attempt, so a failed retry arms the next one. */
(function () {
  var RETRY_SECONDS = 30;

  function hhmm(d) {
    return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
  }

  function asofOf(cell) {
    var box = cell.closest('.grid-stack-item-content, .dash-cell');
    return box ? box.querySelector('.widget-asof') : null;
  }

  function isCell(el) {
    return el && el.classList && el.classList.contains('dash-cell-body');
  }

  function scheduleRetry(cell) {
    clearTimeout(cell._retry);
    if (cell.dataset.poll === '1') return;     // its own poll is the retry
    cell._retry = setTimeout(function () {
      htmx.trigger(cell, 'retry');
    }, RETRY_SECONDS * 1000);
  }

  function failed(cell, why) {
    var asof = asofOf(cell);
    var when = cell.dataset.loadedAt ? new Date(+cell.dataset.loadedAt) : null;
    if (when) {
      // Keep what it showed; say it is no longer current.
      if (asof) {
        asof.textContent = "couldn't refresh · as of " + hhmm(when);
        asof.classList.add('widget-asof-failed');
        asof.title = why;
      }
    } else {
      var retryLine = cell.dataset.poll === '1'
        ? 'Trying again with the next refresh.'
        : 'Trying again in ' + RETRY_SECONDS + 's.';
      cell.innerHTML = '';
      var box = document.createElement('div');
      box.className = 'cell-state cell-state-failed';
      var line = document.createElement('div');
      line.textContent = "Couldn't load this widget (" + why + '). ' + retryLine;
      var btn = document.createElement('button');
      btn.type = 'button';
      btn.className = 'btn btn-sm';
      btn.textContent = 'Retry now';
      btn.addEventListener('click', function () {
        clearTimeout(cell._retry);
        htmx.trigger(cell, 'retry');
      });
      box.appendChild(line);
      box.appendChild(btn);
      cell.appendChild(box);
    }
    scheduleRetry(cell);
  }

  document.body.addEventListener('htmx:afterSwap', function (e) {
    var cell = e.detail.target;
    if (!isCell(cell)) return;
    clearTimeout(cell._retry);
    var now = new Date();
    cell.dataset.loadedAt = String(now.getTime());
    var asof = asofOf(cell);
    if (asof) {
      asof.textContent = 'as of ' + hhmm(now);
      asof.classList.remove('widget-asof-failed');
      asof.title = 'Loaded ' + now.toLocaleString();
    }
  });

  document.body.addEventListener('htmx:responseError', function (e) {
    if (isCell(e.detail.target)) failed(e.detail.target, 'HTTP ' + e.detail.xhr.status);
  });
  document.body.addEventListener('htmx:sendError', function (e) {
    if (isCell(e.detail.target)) failed(e.detail.target, 'no connection');
  });
  document.body.addEventListener('htmx:timeout', function (e) {
    if (isCell(e.detail.target)) failed(e.detail.target, 'timed out');
  });
})();