// Logs page (status/logs.html) — dedicated admin log viewer.
// Two tabs: Error log (calls /api/v1/error-logs) + Container (calls
// /api/v1/logs/containers + /api/v1/logs/container/:id). Mirrors the
// /api/v1/error-logs parser fix from DC-051 — U+2500 separator, capped
// tail, level filter.
(function() {
  'use strict';

  function escapeHtml(s) {
    if (s === null || s === undefined) return '';
    return String(s).replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c]));
  }

  function formatBytes(n) {
    if (!Number.isFinite(n) || n <= 0) return '0 B';
    if (n < 1024) return n + ' B';
    if (n < 1024 * 1024) return (n / 1024).toFixed(1) + ' KiB';
    return (n / 1024 / 1024).toFixed(2) + ' MiB';
  }

  const out = document.getElementById('output');
  const meta = document.getElementById('meta');
  const tabError = document.getElementById('tab-error');
  const tabContainer = document.getElementById('tab-container');
  const errorCtrls = document.getElementById('error-controls');
  const containerCtrls = document.getElementById('container-controls');

  let activeTab = 'error';
  let containers = [];

  function switchTab(tab) {
    activeTab = tab;
    tabError.classList.toggle('active', tab === 'error');
    tabContainer.classList.toggle('active', tab === 'container');
    errorCtrls.style.display = tab === 'error' ? 'flex' : 'none';
    containerCtrls.style.display = tab === 'container' ? 'flex' : 'none';
    if (tab === 'error') loadErrorLog();
    else loadContainerList();
  }

  async function fetchJson(url, opts) {
    const r = await fetch(url, opts);
    const data = await r.json().catch(() => ({}));
    if (!r.ok || (data && data.success === false)) {
      throw new Error((data && (data.error || data.message)) || `HTTP ${r.status}`);
    }
    return data;
  }

  async function loadErrorLog() {
    const tailEl = /** @type {HTMLSelectElement} */ (document.getElementById('tail'));
    const levelEl = /** @type {HTMLSelectElement} */ (document.getElementById('level'));
    const tail = tailEl.value;
    const level = levelEl.value;
    let qs = `tail=${encodeURIComponent(tail)}`;
    if (level) qs += '&level=' + encodeURIComponent(level);

    out.innerHTML = '<div class="logs-loading">Loading error log…</div>';
    meta.textContent = '';
    try {
      const data = await fetchJson('/api/v1/error-logs?' + qs);
      const logs = data.logs || [];
      if (logs.length === 0) {
        out.innerHTML = '<div class="empty">✅ No errors logged</div>';
      } else {
        out.innerHTML = logs.map((log, idx) => {
          const date = new Date(log.timestamp).toLocaleString();
          const lvl = (log.level || 'ERR').toUpperCase();
          const cls = ['ERR','WRN','INF','DBG'].includes(lvl) ? lvl.toLowerCase() : 'error';
          const details = log.details ? escapeHtml(log.details) : null;
          return `
            <div class="log-entry ${cls}">
              <span class="log-timestamp">${escapeHtml(date)}</span>
              <span class="log-level">${escapeHtml(lvl)}</span>
              <div class="log-message">
                <strong>${escapeHtml(log.context || '')}</strong>: ${escapeHtml(log.message || '')}
                ${details ? `<details><summary style="cursor:pointer;opacity:.7">stack + request context</summary><pre>${details}</pre></details>` : ''}
              </div>
            </div>
          `;
        }).join('');
      }
      const sizeStr = formatBytes(data.totalSize);
      const truncStr = data.truncated ? ' (last 2 MiB)' : '';
      const returnedStr = data.returned ?? logs.length;
      meta.textContent = `${returnedStr} entries · ${sizeStr}${truncStr}`;
    } catch (err) {
      out.innerHTML = `<div class="empty">❌ ${escapeHtml(err.message)}</div>`;
    }
  }

  async function clearErrorLog() {
    if (!confirm('Clear all error logs?')) return;
    try {
      await fetchJson('/api/v1/error-logs', { method: 'DELETE' });
      meta.textContent = '✅ cleared';
      loadErrorLog();
    } catch (err) {
      meta.textContent = '❌ ' + err.message;
    }
  }

  async function loadContainerList() {
    const sel = document.getElementById('container-select');
    out.innerHTML = '<div class="logs-loading">Loading containers…</div>';
    document.getElementById('container-meta').textContent = '';
    try {
      const data = await fetchJson('/api/v1/logs/containers');
      containers = data.containers || [];
      sel.innerHTML = containers.map(c => {
        const name = c.name || c.id;
        const state = (c.status || 'unknown');
        return `<option value="${escapeHtml(c.id)}">${escapeHtml(name)} (${escapeHtml(state)})</option>`;
      }).join('');
      if (containers.length === 0) {
        out.innerHTML = '<div class="empty">No containers running</div>';
        return;
      }
      loadContainerLog();
    } catch (err) {
      out.innerHTML = `<div class="empty">❌ ${escapeHtml(err.message)}</div>`;
    }
  }

  async function loadContainerLog() {
    const sel = /** @type {HTMLSelectElement} */ (document.getElementById('container-select'));
    const tailEl = /** @type {HTMLSelectElement} */ (document.getElementById('container-tail'));
    const tail = tailEl.value;
    const id = sel.value;
    if (!id) {
      out.innerHTML = '<div class="empty">Select a container</div>';
      return;
    }
    out.innerHTML = '<div class="logs-loading">Loading container logs…</div>';
    document.getElementById('container-meta').textContent = '';
    try {
      const data = await fetchJson(`/api/v1/logs/container/${encodeURIComponent(id)}?tail=${encodeURIComponent(tail)}&timestamps=true`);
      const logs = data.logs || [];
      if (logs.length === 0) {
        out.innerHTML = '<div class="empty">No log lines</div>';
      } else {
        out.innerHTML = logs.map(l => {
          const cls = l.stream === 'stderr' ? 'error' : 'info';
          const ts = l.timestamp || (data.logs.length ? '' : '');
          return `
            <div class="log-entry ${cls}">
              ${ts ? `<span class="log-timestamp">${escapeHtml(new Date(ts).toLocaleString())}</span>` : ''}
              <span class="log-level">${l.stream === 'stderr' ? 'ERR' : 'OUT'}</span>
              <div class="log-message"><pre style="margin:0;white-space:pre-wrap">${escapeHtml(l.text)}</pre></div>
            </div>
          `;
        }).join('');
      }
      const containerName = data.containerName || '';
      document.getElementById('container-meta').textContent = `${escapeHtml(containerName)} · ${logs.length} lines`;
    } catch (err) {
      out.innerHTML = `<div class="empty">❌ ${escapeHtml(err.message)}</div>`;
    }
  }

  tabError.addEventListener('click', () => switchTab('error'));
  tabContainer.addEventListener('click', () => switchTab('container'));
  document.getElementById('refresh').addEventListener('click', loadErrorLog);
  document.getElementById('clear').addEventListener('click', clearErrorLog);
  document.getElementById('level').addEventListener('change', loadErrorLog);
  document.getElementById('tail').addEventListener('change', loadErrorLog);
  document.getElementById('container-refresh').addEventListener('click', loadContainerLog);
  document.getElementById('container-select').addEventListener('change', loadContainerLog);
  document.getElementById('container-tail').addEventListener('change', loadContainerLog);

  switchTab('error');
})();