// modal.js — reusable themed modal/dialog component for the operator
// dashboard. An in-theme replacement for the browser's native
// `confirm()` / `alert()` overlays so destructive actions and prompts match
// the dashboard chrome instead of a jarring OS dialog.
//
// `openDialog` is the general primitive (any title/message/content + a row of
// buttons); `themedConfirm` is a thin cancel/confirm wrapper with optional
// checkboxes built on top of it. Styling lives in `dashboard.css` under the
// `.tc-*` classes.

import { el } from './common.js';

// openDialog({ title, message, content, buttons, danger, dismissable })
//   → Promise resolving to the clicked button's `value`, or `null` when the
//     dialog is dismissed (Escape, backdrop click, or a button whose value is
//     null). `content` is an optional DOM node rendered between the message
//     and the buttons (checkboxes, custom fields, …). `buttons` is
//     `[{ label, value, danger?, class?, autofocus? }]`, rendered
//     right-aligned. Initial focus: the `autofocus` button if any, else — for
//     a `danger` dialog — the first non-destructive button (so a stray Enter
//     can't fire the destructive path), else the last button.
export function openDialog(opts = {}) {
  const {
    title = '', message = '', content = null,
    buttons = [{ label: 'ok', value: true }],
    danger = false, dismissable = true,
  } = opts;

  return new Promise((resolve) => {
    let settled = false;
    function done(value) {
      if (settled) return;
      settled = true;
      document.removeEventListener('keydown', onKey, true);
      backdrop.remove();
      resolve(value);
    }
    function onKey(e) {
      if (dismissable && e.key === 'Escape') {
        e.preventDefault();
        e.stopPropagation();
        done(null);
      }
    }

    const btnEls = buttons.map((b) => {
      const btn = el('button', {
        type: 'button',
        class: 'btn tc-btn' + (b.class ? ' ' + b.class : '') + (b.danger ? ' tc-danger' : ''),
      }, b.label);
      btn.addEventListener('click', () => done(b.value));
      return { spec: b, btn };
    });

    // Give the dialog an accessible name: label it by its title if present,
    // else by its message, via `aria-labelledby` (a11y — role=dialog needs a
    // name). Only the labelling element carries the id.
    const labelId = 'tc-dlg-' + Math.random().toString(36).slice(2, 9);
    const titleEl = title ? el('div', { class: 'tc-title', id: labelId }, title) : null;
    const messageEl = message
      ? el('div', title ? { class: 'tc-message' } : { class: 'tc-message', id: labelId }, message)
      : null;
    const boxAttrs = { class: 'tc-box', role: 'dialog', 'aria-modal': 'true' };
    if (titleEl || messageEl) boxAttrs['aria-labelledby'] = labelId;
    const box = el('div', boxAttrs,
      titleEl,
      messageEl,
      content || null,
      el('div', { class: 'tc-actions' }, ...btnEls.map((b) => b.btn)));

    const backdrop = el('div', { class: 'tc-backdrop' }, box);
    backdrop.addEventListener('click', (e) => {
      if (dismissable && e.target === backdrop) done(null);
    });
    document.addEventListener('keydown', onKey, true);
    document.body.append(backdrop);

    const focusTarget = btnEls.find((b) => b.spec.autofocus)
      || (danger ? btnEls.find((b) => !b.spec.danger) : null)
      || btnEls[btnEls.length - 1];
    if (focusTarget) focusTarget.btn.focus();
  });
}

// themedConfirm({ title, message, danger, confirmLabel, cancelLabel, checkboxes })
//   → Promise<null | { [name]: bool }>. `null` = cancelled; otherwise an
//   object of the checkbox states keyed by `name` (`{}` when there are none).
//   Example:
//     const r = await themedConfirm({ message: `stop ${n}?`, danger: true,
//       confirmLabel: '■ stop', checkboxes: [{ name: 'graceful', label: '…' }] });
//     if (!r) return;            // cancelled
//     doStop(r.graceful);
export function themedConfirm(opts = {}) {
  const {
    title = '', message = '', danger = false,
    confirmLabel = 'confirm', cancelLabel = 'cancel', checkboxes = [],
  } = opts;

  const boxes = checkboxes.map((cb) => {
    const input = el('input', { type: 'checkbox', class: 'tc-check', name: cb.name });
    if (cb.checked) input.checked = true;
    const row = el('label', { class: 'tc-checkrow' },
      input, el('span', { class: 'tc-check-label' }, cb.label || cb.name));
    return { input, row };
  });
  const content = boxes.length
    ? el('div', { class: 'tc-checks' }, ...boxes.map((b) => b.row))
    : null;

  return openDialog({
    title,
    message,
    content,
    danger,
    buttons: [
      { label: cancelLabel, value: null, class: 'tc-cancel', autofocus: danger },
      { label: confirmLabel, value: 'confirm', danger, class: 'tc-confirm', autofocus: !danger },
    ],
  }).then((v) => {
    if (v !== 'confirm') return null;
    const out = {};
    for (let i = 0; i < boxes.length; i++) out[checkboxes[i].name] = boxes[i].input.checked;
    return out;
  });
}

// themedPrompt({ title, message, label, placeholder, value, confirmLabel, cancelLabel })
//   → Promise<string | null>. Themed replacement for window.prompt(): a
//   resizable <textarea> dialog that resolves to the entered string on confirm,
//   or null on cancel. Chat-box key behaviour: **Enter submits**, **Shift+Enter
//   inserts a newline** — so short answers are one keystroke while multi-line
//   reasons (e.g. an approval deny note) are still possible. Escape cancels
//   (via openDialog).
export function themedPrompt(opts = {}) {
  const {
    title = '', message = '', label = '', placeholder = '', value = '',
    confirmLabel = 'ok', cancelLabel = 'cancel',
  } = opts;
  const input = el('textarea', { class: 'tc-input tc-textarea', rows: '3', placeholder });
  if (value) input.value = value;
  // Enter submits (clicks the confirm button mounted by openDialog);
  // Shift+Enter falls through to the textarea's default newline insert.
  input.addEventListener('keydown', (e) => {
    if (e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault();
      input.closest('.tc-box')?.querySelector('.tc-confirm')?.click();
    }
  });
  const content = el('div', { class: 'tc-promptfield' },
    label ? el('label', { class: 'tc-promptlabel' }, label) : null,
    input);
  const result = openDialog({
    title,
    message,
    content,
    buttons: [
      { label: cancelLabel, value: '__cancel__', class: 'tc-cancel' },
      { label: confirmLabel, value: '__ok__', class: 'tc-confirm', autofocus: true },
    ],
  }).then((v) => (v === '__ok__' ? input.value : null));
  // Prefer focusing the field over the OK button once the dialog has mounted.
  setTimeout(() => input.focus(), 0);
  return result;
}

// themedToast(message, { type, duration }) — non-blocking transient
//   notification; a lighter alternative to a modal for feedback that needs no
//   decision (errors, validation, status). Stacks in a fixed top-right
//   container, auto-dismisses after `duration` ms (errors linger longer), and
//   can be clicked to dismiss early. `type` ∈ {'info','error','ok'}.
export function themedToast(message, opts = {}) {
  const { type = 'info', duration } = opts;
  const ms = duration != null ? duration : (type === 'error' ? 8000 : 4000);
  let container = document.getElementById('tc-toasts');
  if (!container) {
    container = el('div', { id: 'tc-toasts', class: 'tc-toasts' });
    document.body.append(container);
  }
  const toast = el('div', {
    class: 'tc-toast tc-toast-' + type,
    role: type === 'error' ? 'alert' : 'status',
  }, message);
  let removed = false;
  const remove = () => {
    if (removed) return;
    removed = true;
    toast.classList.add('tc-toast-out');
    setTimeout(() => toast.remove(), 200);
  };
  toast.addEventListener('click', remove);
  container.append(toast);
  if (ms > 0) setTimeout(remove, ms);
  return toast;
}