// Incident detail: facts, member alerts, the timeline with notes, and the
// action bar that carries everything a responder does to an incident.

import * as api from './api.js';
import * as poll from './poll.js';
import {
  h, clear, icon, badge, labelChip, openSheet, closeSheet, confirm, toast, spinner, emptyState,
} from './ui.js';
import {
  ago, when, until, isFuture, severityClass, STATUS_LABEL,
} from './format.js';
import { myID, users } from './state.js';
import { back } from './app.js';

const pane = () => document.getElementById('detail');

let currentID = null;
let inc = null;
let events = [];
let error = null;
let busy = false;

export function show(id) {
  if (id === currentID) return;
  currentID = id;
  inc = null;
  events = [];
  error = null;
  if (id == null) {
    renderPlaceholder();
    return;
  }
  render();
  refresh();
}

export async function refresh() {
  const id = currentID;
  if (id == null) return;
  try {
    const [i, t] = await Promise.all([api.incident(id), api.timeline(id)]);
    if (id !== currentID) return;
    inc = i;
    events = t;
    error = null;
  } catch (err) {
    if (id !== currentID) return;
    error = err.status === 404 ? 'This incident does not exist.' : err.message;
  }
  render();
}

function renderPlaceholder() {
  clear(pane(), h('div', { class: 'detail-placeholder' },
    h('div', {}, icon('flag', 'icon'), h('p', { text: 'Select an incident to see its alerts and timeline.' }))));
}

function render() {
  const head = h('div', { class: 'detail-head' },
    h('button', { class: 'btn btn-ghost btn-icon back', type: 'button', 'aria-label': 'Back to queue', onclick: back },
      icon('back')),
    h('span', { class: 'crumb', text: currentID != null ? `Incident #${currentID}` : '' }),
  );

  if (!inc) {
    clear(pane(), h('div', { class: 'detail' }, head,
      error ? h('div', { class: 'load-error', text: error }) : spinner()));
    return;
  }

  // Keep the scroll position across the periodic re-render.
  const scroller = document.querySelector('.pane-detail');
  const top = scroller ? scroller.scrollTop : 0;

  clear(pane(),
    h('article', { class: 'detail' },
      head,
      error && h('div', { class: 'load-error', text: `Showing older data: ${error}` }),
      h('h1', { class: 'detail-title', text: inc.title }),
      h('div', { class: 'detail-badges' }, statusBadges()),
      facts(),
      groupLabels(),
      alertsSection(),
      timelineSection(),
    ),
    actionBar(),
  );
  if (scroller) scroller.scrollTop = top;
}

function statusBadges() {
  const out = [];
  if (inc.severity) out.push(badge(inc.severity, `plain ${severityClass(inc.severity)}`));
  out.push(badge(STATUS_LABEL[inc.status] || inc.status, `st-${inc.status}`));
  if (inc.status !== 'resolved' && isFuture(inc.snoozed_until)) {
    out.push(badge(`Snoozed · ${until(inc.snoozed_until)} left`, 'st-snoozed'));
  }
  if (inc.archived_at) out.push(badge('Archived', 'plain'));
  return out;
}

function who(id, name) {
  if (id != null && id === myID()) return 'you';
  return name || 'someone';
}

function facts() {
  const rows = [];
  const add = (k, ...v) => rows.push(h('dt', { text: k }), h('dd', {}, ...v));
  add('Triggered', when(inc.triggered_at), h('span', { class: 'sub', text: ` · ${ago(inc.triggered_at)}` }));
  if (inc.acknowledged_at) {
    add('Acknowledged', `${who(inc.acknowledged_by_id, inc.acknowledged_by)} · ${when(inc.acknowledged_at)}`);
  }
  add('Assigned', inc.assigned_to_id != null ? who(inc.assigned_to_id, inc.assigned_to) : 'Unassigned');
  if (inc.status !== 'resolved' && isFuture(inc.snoozed_until)) {
    add('Snoozed until', when(inc.snoozed_until));
  }
  if (inc.resolved_at) {
    const how = inc.resolution_source === 'manual' ? 'by hand' : 'alerts stopped firing';
    add('Resolved', when(inc.resolved_at), h('span', { class: 'sub', text: ` · ${how}` }));
  }
  if (inc.archived_at) add('Archived', when(inc.archived_at));
  return h('div', { class: 'card' }, h('dl', { class: 'facts' }, rows));
}

function groupLabels() {
  const entries = Object.entries(inc.group_labels || {});
  if (!entries.length) return null;
  return h('section', { class: 'section' },
    h('h2', { class: 'section-title', text: 'Grouped by' }),
    h('div', { class: 'labels-wrap' }, entries.map(([k, v]) => labelChip(k, v))),
  );
}

function alertsSection() {
  const list = inc.alerts || [];
  const firing = list.filter((a) => a.status === 'firing').length;
  return h('section', { class: 'section' },
    h('h2', { class: 'section-title' },
      h('span', { text: `Alerts (${list.length})` }),
      firing ? h('span', { text: `${firing} firing` }) : null),
    list.length
      ? h('div', { class: 'card' }, list.map(alertItem))
      : h('div', { class: 'card card-pad', text: 'No alerts attached.' }),
  );
}

function alertItem(a) {
  const summary = (a.annotations && (a.annotations.summary || a.annotations.description)) || '';
  const labels = Object.entries(a.labels || {});
  return h('div', { class: 'alert-item' },
    h('div', { class: 'alert-item-head' },
      h('span', { class: 'alert-item-name', text: a.name }),
      badge(a.status === 'firing' ? 'Firing' : 'Resolved', `st-${a.status}`)),
    summary && h('div', { class: 'alert-item-summary', text: summary }),
    h('div', { class: 'alert-item-foot' },
      h('span', { text: `Started ${ago(a.starts_at)}` }),
      h('span', { text: `Last seen ${ago(a.received_at)}` }),
      a.generator_url && h('a', { href: a.generator_url, target: '_blank', rel: 'noopener noreferrer' }, 'Source ↗'),
    ),
    labels.length > 0 && h('details', {},
      h('summary', { text: `${labels.length} labels` }),
      h('div', { class: 'labels-wrap' }, labels.map(([k, v]) => labelChip(k, v)))),
  );
}

// ---------- timeline ----------

function eventText(ev) {
  const person = ev.user_id != null ? who(ev.user_id, ev.username) : null;
  const strong = (t) => h('span', { class: 'who', text: t || 'someone' });
  const alertName = () => {
    const a = (inc.alerts || []).find((x) => x.id === ev.alert_id);
    return a ? a.name : 'an alert';
  };
  switch (ev.type) {
    case 'triggered': return ['Incident triggered'];
    case 'alert_added': return [`Alert added: ${alertName()}`];
    case 'alert_resolved': return [`Alert resolved: ${alertName()}`];
    case 'acknowledged': return [strong(person), ' acknowledged'];
    case 'unacknowledged': return [strong(person), ' cleared the acknowledgement'];
    case 'assigned': return ['Assigned to ', strong(person)];
    case 'snoozed': return [strong(person), ` snoozed until ${ev.detail ? when(ev.detail) : '…'}`];
    case 'unsnoozed': return [strong(person), ' ended the snooze'];
    case 'resolved': return person ? [strong(person), ' resolved the incident'] : ['Resolved: every alert stopped firing'];
    case 'note': return [strong(person), ' added a note'];
    case 'notified': {
      const to = person ? strong(person) : 'the fallback topic';
      if (ev.detail === 'reminder') return ['Reminder sent to ', to];
      if (ev.detail === 'resolved') return ['Resolution sent to ', to];
      return ['Paged ', to];
    }
    case 'notify_failed': return ['Notification failed', ev.detail ? `: ${ev.detail}` : ''];
    case 'deadman_silent': return ['Heartbeat went silent', ev.detail ? ` (${ev.detail})` : ''];
    default: return [ev.type, ev.detail ? `: ${ev.detail}` : ''];
  }
}

function timelineSection() {
  const sorted = [...events].sort((a, b) => Date.parse(a.created_at) - Date.parse(b.created_at) || a.id - b.id);
  return h('section', { class: 'section' },
    h('h2', { class: 'section-title' },
      h('span', { text: 'Timeline' }),
      h('button', { class: 'btn btn-ghost btn-sm', type: 'button', onclick: addNote },
        icon('note'), 'Add note')),
    h('div', { class: 'card' },
      sorted.length
        ? h('ol', { class: 'timeline' }, sorted.map(timelineItem))
        : emptyState('No events yet', '')),
  );
}

function timelineItem(ev) {
  const mine = ev.type === 'note' && ev.user_id === myID();
  return h('li', { class: `tl-item tl-${ev.type}` },
    h('span', { class: 'tl-dot' }),
    h('div', { class: 'tl-body' },
      h('div', { class: 'tl-text' }, eventText(ev)),
      h('div', { class: 'tl-time', title: ev.created_at, text: `${when(ev.created_at)} · ${ago(ev.created_at)}` }),
      ev.type === 'note' && h('div', { class: 'note', text: ev.detail || '' }),
      mine && h('div', { class: 'note-actions' },
        h('button', { class: 'btn btn-ghost btn-sm', type: 'button', onclick: () => deleteNote(ev) }, icon('trash'), 'Delete')),
    ),
  );
}

// ---------- actions ----------

const isOpen = () => inc.status !== 'resolved';
const isSnoozed = () => isOpen() && isFuture(inc.snoozed_until);

function actionBar() {
  let primary;
  let secondary;
  if (inc.status === 'triggered') {
    primary = h('button', { class: 'btn btn-primary', type: 'button', onclick: acknowledge }, icon('check'), 'Acknowledge');
  } else if (inc.status === 'acknowledged') {
    primary = h('button', { class: 'btn btn-primary', type: 'button', onclick: resolve }, icon('checkCircle'), 'Resolve');
  } else {
    primary = inc.archived_at
      ? h('button', { class: 'btn btn-primary', type: 'button', onclick: unarchive }, icon('undo'), 'Unarchive')
      : h('button', { class: 'btn btn-primary', type: 'button', onclick: archive }, icon('archive'), 'Archive');
  }
  if (isOpen()) {
    secondary = isSnoozed()
      ? h('button', { class: 'btn', type: 'button', onclick: unsnooze }, icon('bell'), 'Unsnooze')
      : h('button', { class: 'btn', type: 'button', onclick: snooze }, icon('clock'), 'Snooze');
  } else {
    secondary = h('button', { class: 'btn', type: 'button', onclick: addNote }, icon('note'), 'Note');
  }
  const more = h('button', { class: 'btn btn-icon', type: 'button', 'aria-label': 'More actions', onclick: moreMenu }, icon('more'));
  const bar = h('div', { class: 'actionbar' }, primary, secondary, more);
  if (busy) for (const b of bar.querySelectorAll('button')) b.disabled = true;
  return bar;
}

// run performs one action, then reloads the incident and the queue.
async function run(fn, done) {
  if (busy) return;
  busy = true;
  render();
  try {
    await fn();
    if (done) toast(done);
  } catch (err) {
    toast(err.message, 'error');
  } finally {
    busy = false;
    await refresh();
    poll.now();
  }
}

function acknowledge() {
  const id = inc.id;
  return run(() => api.acknowledge(id), 'Acknowledged');
}

function unacknowledge() {
  const id = inc.id;
  return run(() => api.unacknowledge(id), 'Acknowledgement cleared');
}

async function resolve() {
  const id = inc.id;
  const ok = await confirm({
    title: 'Resolve this incident?',
    text: 'Resolving is final. If these alerts fire again they open a new incident, '
      + 'and if any are still firing this one stays closed regardless. '
      + 'Use snooze if you only need it out of the way.',
    confirmLabel: 'Resolve',
    danger: true,
  });
  if (ok) await run(() => api.resolve(id), 'Resolved');
}

function archive() {
  const id = inc.id;
  return run(() => api.archive(id), 'Archived');
}

function unarchive() {
  const id = inc.id;
  return run(() => api.unarchive(id), 'Unarchived');
}

function unsnooze() {
  const id = inc.id;
  return run(() => api.unsnooze(id), 'Snooze ended');
}

async function snooze() {
  const id = inc.id;
  const tomorrow9 = new Date();
  tomorrow9.setDate(tomorrow9.getDate() + 1);
  tomorrow9.setHours(9, 0, 0, 0);

  const options = [
    ['30 minutes', { duration: '30m' }],
    ['1 hour', { duration: '1h' }],
    ['2 hours', { duration: '2h' }],
    ['4 hours', { duration: '4h' }],
    ['8 hours', { duration: '8h' }],
    ['Until 09:00 tomorrow', { until: tomorrow9.toISOString() }],
  ];
  const spec = await openSheet(() => [
    h('h2', { class: 'sheet-title', text: 'Snooze' }),
    h('p', { class: 'sheet-text', text: 'Hide it from the queue for a while. It comes back on its own.' }),
    h('ul', { class: 'menu' }, options.map(([label, value]) =>
      h('li', {}, h('button', { class: 'menu-item', type: 'button', onclick: () => closeSheet(value) },
        icon('clock'), label)))),
  ]);
  if (spec) await run(() => api.snooze(id, spec), 'Snoozed');
}

async function assign() {
  const id = inc.id;
  let list;
  let onCall;
  try {
    [list, onCall] = await Promise.all([users(), api.onCallNow()]);
  } catch (err) {
    toast(err.message, 'error');
    return;
  }
  const me = myID();
  const sorted = [...list].sort((a, b) => (b.id === me) - (a.id === me) || a.username.localeCompare(b.username));
  const userID = await openSheet(() => [
    h('h2', { class: 'sheet-title', text: 'Assign to' }),
    h('ul', { class: 'menu', role: 'menu' }, sorted.map((u) =>
      h('li', {}, h('button', {
        class: 'menu-item',
        type: 'button',
        role: 'menuitemradio',
        'aria-checked': String(u.id === inc.assigned_to_id),
        onclick: () => closeSheet(u.id),
      },
        icon('user'),
        u.id === me ? `${u.username} (you)` : u.username,
        onCall && onCall.user_id === u.id ? h('span', { class: 'menu-sub', text: 'on call' }) : null,
      )))),
  ]);
  if (userID != null) await run(() => api.assign(id, userID), 'Assigned');
}

async function addNote() {
  const id = inc.id;
  const content = await openSheet(() => {
    const textarea = h('textarea', {
      name: 'content', required: true, autofocus: true, placeholder: 'What did you find? What did you do?', maxlength: '10000',
    });
    const form = h('form', {
      class: 'sheet-form',
      onsubmit: (e) => {
        e.preventDefault();
        const v = textarea.value.trim();
        if (v) closeSheet(v);
      },
    },
      h('h2', { class: 'sheet-title', text: 'Add note' }),
      textarea,
      h('div', { class: 'sheet-actions' },
        h('button', { class: 'btn', type: 'button', onclick: () => closeSheet(null), text: 'Cancel' }),
        h('button', { class: 'btn btn-primary', type: 'submit', text: 'Save note' })),
    );
    // Ctrl/Cmd+Enter saves, as in most note fields.
    textarea.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' && (e.ctrlKey || e.metaKey)) form.requestSubmit();
    });
    return form;
  });
  if (content) await run(() => api.addNote(id, content), 'Note added');
}

async function deleteNote(ev) {
  const id = inc.id;
  const ok = await confirm({ title: 'Delete this note?', text: ev.detail || '', confirmLabel: 'Delete', danger: true });
  if (ok) await run(() => api.deleteNote(id, ev.id), 'Note deleted');
}

async function moreMenu() {
  const item = (iconName, label, fn, cls = '') =>
    h('li', {}, h('button', { class: `menu-item ${cls}`, type: 'button', onclick: () => closeSheet(fn) }, icon(iconName), label));

  const items = [];
  if (isOpen()) {
    if (inc.status === 'triggered') items.push(item('check', 'Acknowledge', acknowledge));
    else items.push(item('undo', 'Clear acknowledgement', unacknowledge));
    items.push(item('user', 'Assign…', assign));
    items.push(isSnoozed() ? item('bell', 'End snooze', unsnooze) : item('clock', 'Snooze…', snooze));
    items.push(item('note', 'Add note…', addNote));
    items.push(h('li', { class: 'menu-sep', role: 'separator' }));
    items.push(item('checkCircle', 'Resolve…', resolve, 'danger'));
  } else {
    items.push(item('note', 'Add note…', addNote));
    items.push(inc.archived_at ? item('undo', 'Unarchive', unarchive) : item('archive', 'Archive', archive));
  }

  const fn = await openSheet(() => [
    h('h2', { class: 'sheet-title', text: inc.title }),
    h('ul', { class: 'menu' }, items),
  ]);
  if (fn) await fn();
}

// key handles the detail's shortcuts. Returns true when it used the key.
export function key(e) {
  if (!inc) {
    if (e.key === 'Escape') {
      back();
      return true;
    }
    return false;
  }
  switch (e.key) {
    case 'Escape': back(); return true;
    case 'a': if (inc.status === 'triggered') acknowledge(); return true;
    case 'A': if (inc.status === 'acknowledged') unacknowledge(); return true;
    case 'R': if (isOpen()) resolve(); return true;
    case 's': if (isOpen()) assign(); return true;
    case 'z': if (isOpen() && !isSnoozed()) snooze(); return true;
    case 'Z': if (isSnoozed()) unsnooze(); return true;
    case 'c': addNote(); return true;
    case 'x': if (!isOpen()) (inc.archived_at ? unarchive() : archive()); return true;
    default: return false;
  }
}