/**
 * Declarative confirm-before-action — intercepts clicks and submits on [data-confirm-message] elements.
 */
import { confirmDialog, requestSubmitWithFallback } from '../core/app-confirm-dialog.js';
import { isSubmitControl, belongsToForm } from '../core/app-form-utils.js';

const CONFIRM_ATTR = 'data-confirm-message';
const BOUND_KEY = '_confirmActionsBound';
const confirmedSubmitterByForm = new WeakMap();
const confirmedClickElements = new WeakSet();

const trimAttr = (element, attr) => String(element?.getAttribute(attr) || '').trim();

const submitterByForm = new Map();

const readConfirmOption = (primary, fallback, suffix) => {
  const attr = `data-confirm-${suffix}`;
  return trimAttr(primary, attr) || trimAttr(fallback, attr);
};

const buildConfirmOptions = (message, primary, fallback) => ({
  message,
  title: readConfirmOption(primary, fallback, 'title'),
  confirmLabel: readConfirmOption(primary, fallback, 'confirm-label'),
  cancelLabel: readConfirmOption(primary, fallback, 'cancel-label'),
  variant: readConfirmOption(primary, fallback, 'variant'),
  focus: readConfirmOption(primary, fallback, 'focus'),
  describedBy: readConfirmOption(primary, fallback, 'describedby')
    || readConfirmOption(primary, fallback, 'described-by'),
  actionKind: readConfirmOption(primary, fallback, 'action-kind')
});

const onClickCapture = (event) => {
  const trigger = event.target instanceof HTMLElement ? event.target.closest('a, button, input') : null;
  if (!(trigger instanceof HTMLElement)) {
    return;
  }

  if (confirmedClickElements.has(trigger)) {
    confirmedClickElements.delete(trigger);
    return;
  }

  if (isSubmitControl(trigger)) {
    const form = trigger.form instanceof HTMLFormElement ? trigger.form : null;
    if (form) {
      submitterByForm.set(form, trigger);
    }
    return;
  }

  const confirmMessage = String(trigger.getAttribute(CONFIRM_ATTR) || '').trim();
  if (confirmMessage === '') {
    return;
  }

  event.preventDefault();
  event.stopPropagation();

  void confirmDialog.confirm(buildConfirmOptions(confirmMessage, trigger, null))
    .then((approved) => {
      if (!approved || !document.contains(trigger)) {
        return;
      }
      confirmedClickElements.add(trigger);
      trigger.click();
    });
};

const onSubmitCapture = (event) => {
  const form = event.target instanceof HTMLFormElement ? event.target : null;
  if (!(form instanceof HTMLFormElement)) {
    return;
  }

  const submitter = event.submitter instanceof HTMLElement
    ? event.submitter
    : (submitterByForm.get(form) || null);
  submitterByForm.delete(form);

  const confirmedSubmitter = confirmedSubmitterByForm.get(form);
  if (confirmedSubmitter && (confirmedSubmitter === true || confirmedSubmitter === submitter || confirmedSubmitter === null)) {
    confirmedSubmitterByForm.delete(form);
    return;
  }

  const submitterMessage = String(submitter?.getAttribute(CONFIRM_ATTR) || '').trim();
  const formMessage = String(form.getAttribute(CONFIRM_ATTR) || '').trim();
  const confirmMessage = submitterMessage !== '' ? submitterMessage : formMessage;

  if (confirmMessage === '') {
    return;
  }

  event.preventDefault();
  event.stopPropagation();

  void confirmDialog.confirm(buildConfirmOptions(confirmMessage, submitter, form))
    .then((approved) => {
      if (!approved || !document.contains(form)) {
        return;
      }
      const submitterForSubmit = submitter && belongsToForm(submitter, form) ? submitter : null;
      confirmedSubmitterByForm.set(form, submitterForSubmit || true);
      requestSubmitWithFallback(form, submitterForSubmit);
    });
};

export function initConfirmActions(root = document) {
  const host = root && typeof root.addEventListener === 'function' ? root : document;
  if (host[BOUND_KEY]) {
    return { destroy: () => {} };
  }
  host[BOUND_KEY] = true;

  host.addEventListener('click', onClickCapture, true);
  host.addEventListener('submit', onSubmitCapture, true);

  const destroy = () => {
    host.removeEventListener('click', onClickCapture, true);
    host.removeEventListener('submit', onSubmitCapture, true);
    delete host[BOUND_KEY];
  };
  return { destroy };
}