/**
 * @file helpAutomat.js
 * @description Manages global interactive help badges and active popper state.
 * Persisted in IndexedDB across browser reloads.
 *
 * Upstream Triggers:
 * - UI / User interaction: Calls to `toggle()`, `setEnabled()`, `openPopper()`,
 *   and `closePopper()`.
 */

import { Automat } from 'react-automat';

/**
 * @typedef {Object} HelpState
 * @property {boolean} enabled Whether interactive help badges are enabled systemwide.
 * @property {string|null} activeHelpId ID of the currently open help popper (only one can be open at a time).
 */

/** @type {HelpState} */
const initialState = {
  enabled: false,
  activeHelpId: null,
};

/**
 * Global reactive state for systemwide help badges mode.
 * Persisted in IndexedDB so the setting survives page reloads and sessions.
 * Registered as a named automat ('help') on window.__AUTOMATS__.
 *
 * @type {Automat<HelpState>}
 */
const helpAutomat = new Automat(
  initialState,
  {
    /**
     * Toggles the systemwide help mode on or off.
     */
    toggle() {
      helpAutomat.setState((prev) => {
        const nextEnabled = !prev?.enabled;
        return {
          enabled: nextEnabled,
          activeHelpId: nextEnabled ? prev?.activeHelpId ?? null : null,
        };
      });
    },
    /**
     * Explicitly set whether help mode is enabled.
     * @param {boolean} enabled
     */
    setEnabled(enabled) {
      const nextEnabled = Boolean(enabled);
      helpAutomat.setState((prev) => ({
        enabled: nextEnabled,
        activeHelpId: nextEnabled ? prev?.activeHelpId ?? null : null,
      }));
    },
    /**
     * Open a specific help popper, automatically closing any other currently open popper.
     * @param {string} id
     */
    openPopper(id) {
      helpAutomat.setState({ activeHelpId: id });
    },
    /**
     * Close the currently active help popper.
     */
    closePopper() {
      helpAutomat.setState({ activeHelpId: null });
    },
    /**
     * Toggle a specific help popper open/closed.
     * @param {string} id
     */
    togglePopper(id) {
      helpAutomat.setState((prev) => ({
        activeHelpId: prev?.activeHelpId === id ? null : id,
      }));
    },
  },
  {
    name: 'help',
    persist: true,
  }
);

// Clear active popper on initial boot / persistence hydration
void helpAutomat.ready.then(() => {
  if (helpAutomat.state?.activeHelpId) {
    helpAutomat.setState({ activeHelpId: null });
  }
});

export default helpAutomat;
export const {
  toggle: toggleHelp,
  setEnabled: setHelpEnabled,
  openPopper: openHelpPopper,
  closePopper: closeHelpPopper,
  togglePopper: toggleHelpPopper,
} = helpAutomat.actions;
export const isHelpEnabled = (state = helpAutomat.state) => Boolean(state?.enabled);
export const selectActiveHelpId = (state = helpAutomat.state) => state?.activeHelpId ?? null;