/* =====================================================================
   PULSE — Dashboard page (WP-C)
   Owns DOM id prefix `dash-` and action namespace `dash:*`.
   ===================================================================== */
'use strict';

(function () {
  const esc = Pulse.esc;
  const fmt = Pulse.fmt;

  let _executions = [];
  let _workers = [];

  function parseMeta(worker) {
    if (!worker || !worker.metadata) return null;
    if (typeof worker.metadata === 'string') {
      try { return JSON.parse(worker.metadata); } catch (e) { return null; }
    }
    return worker.metadata;
  }

  function isAutomated(exec) {
    const by = String((exec && exec.started_by) || '');
    return by.indexOf('gandalf:') === 0 || by.indexOf('scheduler:') === 0;
  }

  /* -------------------------------------------------------------------
     Stats
     ------------------------------------------------------------------- */
  function renderStats(workers, runningTotal) {
    const total = workers.length;
    const online = workers.filter(w => w.status === 'online').length;
    const offline = total - online;
    const set = (id, val) => {
      const el = document.getElementById(id);
      if (el) el.textContent = String(val);
    };
    set('dash-stat-total-val', total);
    set('dash-stat-online-val', online);
    set('dash-stat-offline-val', offline);
    set('dash-stat-running-val', runningTotal);
  }

  /* -------------------------------------------------------------------
     Recent executions (5 most recent manual runs)
     ------------------------------------------------------------------- */
  function executionRowHtml(e) {
    const statusClass = fmt.status(e.status);
    const statusText = esc(String(e.status || '').toUpperCase());
    const name = e.workflow_name ? esc(e.workflow_name) : '[Quick Command]';
    const startedBy = esc(e.started_by || '');
    const startedAt = fmt.dateTime(e.started_at);
    const isRunning = String(e.status || '').toLowerCase() === 'running';
    const elapsed = isRunning ? esc(fmt.elapsed(e.started_at)) : '—';
    return (
      '<tr data-action="dash:open-execution" data-execution-id="' + esc(e.id) + '">' +
        '<td data-label="Status"><span class="' + statusClass + '">' + statusText + '</span></td>' +
        '<td data-label="Name">' + name + '</td>' +
        '<td data-label="Started By">' + startedBy + '</td>' +
        '<td data-label="Started At">' + esc(startedAt) + '</td>' +
        '<td data-label="Elapsed" class="dash-elapsed"' +
          (isRunning ? ' data-started-at="' + esc(e.started_at) + '"' : '') + '>' + elapsed + '</td>' +
      '</tr>'
    );
  }

  function renderExecutions(executions) {
    const wrap = document.getElementById('dash-executions-wrap');
    if (!wrap) return;
    const manual = executions.filter(e => !isAutomated(e)).slice(0, 5);
    if (manual.length === 0) {
      wrap.innerHTML =
        '<div class="lt-empty-state lt-empty-state--sm">' +
          '<div class="lt-empty-state-title">No executions yet</div>' +
        '</div>';
      return;
    }
    wrap.innerHTML =
      '<table class="lt-table lt-table-sm lt-table-responsive">' +
        '<thead><tr><th>Status</th><th>Name</th><th>Started By</th><th>Started At</th><th>Elapsed</th></tr></thead>' +
        '<tbody>' + manual.map(executionRowHtml).join('') + '</tbody>' +
      '</table>';
  }

  /* -------------------------------------------------------------------
     Workers summary
     ------------------------------------------------------------------- */
  function workerRowHtml(w) {
    const meta = parseMeta(w);
    const dotClass = w.status === 'online' ? 'lt-dot-up' : 'lt-dot-down';
    const statusClass = fmt.status(w.status);
    const lastSeen = fmt.ago(w.last_heartbeat);
    let stats = '';
    if (meta) {
      stats =
        '<span>CPU: ' + esc(meta.cpus || '?') + ' cores</span>' +
        '<span>RAM: ' + fmt.bytes(meta.totalMem - meta.freeMem) + ' / ' + fmt.bytes(meta.totalMem) + '</span>' +
        '<span>Tasks: ' + esc(meta.activeTasks || 0) + '/' + esc(meta.maxConcurrentTasks || 0) + '</span>';
    }
    return (
      '<div class="dash-worker-row" data-worker-id="' + esc(w.id) + '">' +
        '<div class="dash-worker-main">' +
          '<span class="lt-dot ' + dotClass + '"></span>' +
          '<span class="dash-worker-name">' + esc(w.name) + '</span>' +
          '<span class="' + statusClass + '">' + esc(String(w.status || '').toUpperCase()) + '</span>' +
          '<span class="dash-worker-lastseen" data-last-heartbeat="' + esc(w.last_heartbeat || '') + '">Last seen: ' + esc(lastSeen) + '</span>' +
        '</div>' +
        (stats ? '<div class="dash-worker-stats">' + stats + '</div>' : '') +
      '</div>'
    );
  }

  function renderWorkers(workers) {
    const wrap = document.getElementById('dash-workers-wrap');
    if (!wrap) return;
    if (workers.length === 0) {
      wrap.innerHTML =
        '<div class="lt-empty-state lt-empty-state--sm">' +
          '<div class="lt-empty-state-title">No workers connected</div>' +
        '</div>';
      return;
    }
    wrap.innerHTML = '<div class="dash-worker-list">' + workers.map(workerRowHtml).join('') + '</div>';
  }

  /* -------------------------------------------------------------------
     Live tick — update elapsed times on running rows and worker last-seen
     ------------------------------------------------------------------- */
  function onTick() {
    document.querySelectorAll('#dash-executions-wrap .dash-elapsed[data-started-at]').forEach(el => {
      el.textContent = fmt.elapsed(el.getAttribute('data-started-at'));
    });
    document.querySelectorAll('#dash-workers-wrap .dash-worker-lastseen[data-last-heartbeat]').forEach(el => {
      const v = el.getAttribute('data-last-heartbeat');
      if (v) el.textContent = 'Last seen: ' + fmt.ago(v);
    });
  }

  /* -------------------------------------------------------------------
     Data loading
     ------------------------------------------------------------------- */
  async function loadWorkers() {
    try {
      _workers = await Pulse.api.get('/api/workers') || [];
    } catch (e) {
      _workers = [];
      console.error('[Pulse:dashboard] failed to load workers', e);
    }
    renderWorkers(_workers);
    return _workers;
  }

  async function loadExecutions() {
    try {
      const data = await Pulse.api.get('/api/executions?limit=50&hide_internal=true');
      _executions = (data && data.executions) || [];
    } catch (e) {
      _executions = [];
      console.error('[Pulse:dashboard] failed to load executions', e);
    }
    renderExecutions(_executions);
    return _executions;
  }

  async function loadRunningCount() {
    try {
      const data = await Pulse.api.get('/api/executions?status=running&limit=1');
      return (data && data.total) || 0;
    } catch (e) {
      console.error('[Pulse:dashboard] failed to load running count', e);
      return 0;
    }
  }

  async function refresh() {
    const [workers, , runningTotal] = await Promise.all([
      loadWorkers(),
      loadExecutions(),
      loadRunningCount(),
    ]);
    renderStats(workers, runningTotal);
  }

  function init() {
    Pulse.actions.registerAll({
      'dash:goto-workers': () => { window.location.href = '/workers'; },
      'dash:goto-executions': () => { window.location.href = '/executions'; },
      'dash:open-execution': (el) => {
        const id = el.getAttribute('data-execution-id');
        if (id) window.location.href = '/executions?open=' + encodeURIComponent(id);
      },
    });
    Pulse.events.on('tick', onTick);
    return refresh();
  }

  function onEvent(type) {
    if (type === 'worker_update') {
      Promise.all([loadWorkers(), loadRunningCount()]).then(([workers, rt]) => renderStats(workers, rt));
      return true;
    }
    if (type === 'execution_started' || type === 'execution_status' ||
        type === 'command_result' || type === 'workflow_result' ||
        type === 'executions_bulk_deleted') {
      Promise.all([loadExecutions(), loadRunningCount()]).then(([, rt]) => renderStats(_workers, rt));
      return true;
    }
    return false;
  }

  Pulse.registerPage({ name: 'dashboard', init, refresh, onEvent });
})();