// DOM helpers, the bottom sheet, confirmation and toasts.

// h builds an element. attrs: class, text, on<event>, dataset, aria/other
// attributes; boolean true sets an empty attribute, false/null skips it.
export function h(tag, attrs = {}, ...children) {
  const el = document.createElement(tag);
  for (const [k, v] of Object.entries(attrs || {})) {
    if (v == null || v === false) continue;
    if (k === 'class') el.className = v;
    else if (k === 'text') el.textContent = v;
    else if (k === 'dataset') Object.assign(el.dataset, v);
    else if (k.startsWith('on') && typeof v === 'function') el.addEventListener(k.slice(2), v);
    else if (k in el && typeof v !== 'string') el[k] = v;
    else el.setAttribute(k, v === true ? '' : v);
  }
  append(el, children);
  return el;
}

function append(el, children) {
  for (const c of children.flat(Infinity)) {
    if (c == null || c === false) continue;
    el.append(c instanceof Node ? c : document.createTextNode(String(c)));
  }
}

export function clear(el, ...children) {
  el.replaceChildren();
  append(el, children);
  return el;
}

// Stroke icons, 24×24. Built as SVG nodes so the CSP needs no inline anything.
const ICONS = {
  back: ['M15 18l-6-6 6-6'],
  more: ['M5 12h.01M12 12h.01M19 12h.01'],
  queueList: ['M4 6h16M4 12h16M4 18h10'],
  calendar: ['rect:3.5,5,17,15,2', 'M3.5 10h17M8 3v4M16 3v4'],
  team: ['circle:9,8,3', 'circle:17,9,2.5', 'M3 19a6 6 0 0 1 12 0M15 19a5 5 0 0 1 6-4'],
  shield: ['M12 3l7 3v6c0 4-3 7-7 9-4-2-7-5-7-9V6z'],
  check: ['M5 12.5l4.5 4.5L19 7'],
  checkCircle: ['M8 12.5l3 3 5-6', 'circle:12,12,9'],
  undo: ['M9 14L4 9l5-5', 'M4 9h10a6 6 0 0 1 0 12h-3'],
  user: ['circle:12,8,3.5', 'M5 20a7 7 0 0 1 14 0'],
  clock: ['circle:12,12,9', 'M12 7v5l3 2'],
  bell: ['M6 16V11a6 6 0 0 1 12 0v5l1.5 2h-15z', 'M10 20.5a2 2 0 0 0 4 0'],
  note: ['M5 4h14v12l-4 4H5z', 'M15 20v-4h4', 'M9 9h6M9 13h4'],
  archive: ['M3.5 5h17v4h-17z', 'M5 9v10h14V9', 'M10 13h4'],
  flag: ['M5 21V4', 'M5 4h11l-2 4 2 4H5'],
  trash: ['M4 7h16', 'M9 7V4h6v3', 'M6 7l1 13h10l1-13'],
  chevronLeft: ['M15 18l-6-6 6-6'],
  chevronRight: ['M9 6l6 6-6 6'],
  external: ['M14 4h6v6', 'M20 4l-9 9', 'M18 14v6H4V6h6'],
  logout: ['M15 4h4v16h-4', 'M10 17l5-5-5-5', 'M15 12H4'],
};

const SVG = 'http://www.w3.org/2000/svg';
export function icon(name, cls = 'icon') {
  const svg = document.createElementNS(SVG, 'svg');
  svg.setAttribute('viewBox', '0 0 24 24');
  svg.setAttribute('aria-hidden', 'true');
  svg.setAttribute('class', cls);
  for (const d of ICONS[name] || []) {
    let node;
    if (d.startsWith('circle:')) {
      const [cx, cy, r] = d.slice(7).split(',');
      node = document.createElementNS(SVG, 'circle');
      node.setAttribute('cx', cx);
      node.setAttribute('cy', cy);
      node.setAttribute('r', r);
    } else if (d.startsWith('rect:')) {
      const [x, y, w, hgt, rx] = d.slice(5).split(',');
      node = document.createElementNS(SVG, 'rect');
      node.setAttribute('x', x);
      node.setAttribute('y', y);
      node.setAttribute('width', w);
      node.setAttribute('height', hgt);
      if (rx) node.setAttribute('rx', rx);
    } else {
      node = document.createElementNS(SVG, 'path');
      node.setAttribute('d', d);
    }
    svg.append(node);
  }
  return svg;
}

// ---------- sheet ----------

const sheet = () => document.getElementById('sheet');
let sheetResolve = null;

// openSheet shows content in the bottom sheet (a centred dialog on desktop)
// and resolves with whatever closeSheet is given, or null when dismissed.
export function openSheet(build) {
  const dlg = sheet();
  if (dlg.open) closeSheet(null);
  const inner = h('div', { class: 'sheet-inner' }, h('div', { class: 'sheet-grab' }));
  append(inner, [build()]);
  clear(dlg, inner);
  dlg.showModal();
  const first = dlg.querySelector('[autofocus]');
  if (first) first.focus();
  return new Promise((resolve) => {
    sheetResolve = resolve;
  });
}

export function closeSheet(value = null) {
  const dlg = sheet();
  const resolve = sheetResolve;
  sheetResolve = null;
  if (dlg.open) dlg.close();
  if (resolve) resolve(value);
}

export function sheetIsOpen() {
  return sheet().open;
}

export function initSheet() {
  const dlg = sheet();
  // A tap on the backdrop lands on the dialog element itself.
  dlg.addEventListener('click', (e) => {
    if (e.target === dlg) closeSheet(null);
  });
  dlg.addEventListener('cancel', (e) => {
    e.preventDefault();
    closeSheet(null);
  });
}

// confirm asks a yes/no question in the sheet.
export function confirm({ title, text, confirmLabel = 'Confirm', danger = false }) {
  return openSheet(() => [
    h('h2', { class: 'sheet-title', text: title }),
    text && h('p', { class: 'sheet-text', text }),
    h('div', { class: 'sheet-actions' },
      h('button', { class: 'btn', type: 'button', onclick: () => closeSheet(false), text: 'Cancel' }),
      h('button', {
        class: `btn ${danger ? 'btn-danger' : 'btn-primary'}`,
        type: 'button',
        autofocus: true,
        onclick: () => closeSheet(true),
        text: confirmLabel,
      }),
    ),
  ]).then((v) => v === true);
}

// ---------- toast ----------

let toastTimer = 0;
export function toast(message, kind = '') {
  const el = document.getElementById('toast');
  el.textContent = message;
  el.className = `toast ${kind}`;
  el.hidden = false;
  clearTimeout(toastTimer);
  toastTimer = setTimeout(() => {
    el.hidden = true;
  }, kind === 'error' ? 5000 : 2500);
}

// ---------- misc ----------

export function badge(text, cls = '') {
  return h('span', { class: `badge ${cls}`, text });
}

export function labelChip(k, v) {
  return h('span', { class: 'label', title: `${k}=${v}` }, h('span', { text: k }), h('span', { text: v }));
}

// One entry in a section's overview: a card that is a link, carrying the count
// only that section can state. Both the Admin tab and the Team tab open on one
// of these menus, and a menu item is a shape rather than a page's own idea.
export function menuCard(href, label, count, note) {
  return h('a', { class: 'card overview-item', href },
    h('div', { class: 'overview-head' },
      h('strong', { text: label }),
      count != null && h('span', { class: 'overview-count', text: String(count) })),
    h('p', { class: 'muted small', text: note }),
  );
}

export function emptyState(title, text, iconName) {
  return h('div', { class: 'empty' },
    iconName && icon(iconName),
    h('strong', { text: title }),
    text && h('span', { text }),
  );
}

export function spinner() {
  return h('div', { class: 'empty' }, h('span', { class: 'spinner' }));
}