/**
 * @file posterminalAutomat.js
 * @description Manages registered Point-of-Sale (POS) hardware terminals and
 * their enabled category mappings for the active company.
 *
 * Upstream Triggers:
 * - `authAutomat`: Subscribes to auth state changes — calls `actions.load()` on
 *   `'authed'` with a `selectedCompanyId`, and `actions.reset()` on `'anon'`.
 * - `companyAutomat`: Reads `companyAutomat.state.current?.id` as fallback when loading.
 * - UI / Settings: POS terminal actions (`create`, `delete`, `toggleCategory`, `setCategoryEnabled`).
 */

import { Automat } from 'react-automat';
import { posterminal as posterminalApi } from '../api';
import authAutomat from './authAutomat';
import companyAutomat from './companyAutomat';

/**
 * @typedef {Object} PosterminalState
 * @property {Array<object>} terminals
 * @property {number|string|null} companyId
 * @property {'idle'|'loading'|'succeeded'|'failed'} status
 * @property {string|null} error
 */

/** @type {PosterminalState} */
const initialState = {
  terminals: [],
  companyId: null,
  status: 'idle',
  error: null,
};

let posterminalAutomat;

const actions = {
  /** Load all posterminals for the selected company. */
  async load() {
    const companyId = authAutomat.state.user?.selectedCompanyId ?? companyAutomat.state.current?.id;
    if (!companyId) return [];
    posterminalAutomat.setState({ status: 'loading', error: null });
    try {
      const res = await posterminalApi.list();
      const terminals = Array.isArray(res.posterminals) ? res.posterminals : [];
      posterminalAutomat.setState({ terminals, companyId, status: 'succeeded' });
      return terminals;
    } catch (err) {
      posterminalAutomat.setState({ status: 'failed', error: err?.message ?? String(err) });
      throw err;
    }
  },

  /**
   * Create a new posterminal.
   * @param {{ name: string }} param0
   */
  async create({ name }) {
    const res = await posterminalApi.create({ name });
    const terminal = res.posterminal;
    posterminalAutomat.setState({
      terminals: [...posterminalAutomat.state.terminals, terminal],
    });
    return terminal;
  },

  /**
   * Delete a posterminal.
   * @param {number} terminalId
   */
  async delete(terminalId) {
    await posterminalApi.delete(terminalId);
    posterminalAutomat.setState({
      terminals: posterminalAutomat.state.terminals.filter((t) => t.id !== terminalId),
    });
  },

  /**
   * Enable all categories on a terminal.
   * @param {{ terminalId: number }} param0
   */
  async enableAll({ terminalId }) {
    const res = await posterminalApi.enableAllCategories(terminalId);
    patchTerminalCategories(terminalId, res.categoryIds);
    return res;
  },

  /**
   * Disable all categories on a terminal.
   * @param {{ terminalId: number }} param0
   */
  async disableAll({ terminalId }) {
    const res = await posterminalApi.disableAllCategories(terminalId);
    patchTerminalCategories(terminalId, res.categoryIds);
    return res;
  },

  /**
   * Enable a specific category on a terminal.
   * @param {{ terminalId: number, categoryId: number }} param0
   */
  async enableCategory({ terminalId, categoryId }) {
    const res = await posterminalApi.enableCategory(terminalId, categoryId);
    patchTerminalCategories(terminalId, res.categoryIds);
    return res;
  },

  /**
   * Disable a specific category on a terminal.
   * @param {{ terminalId: number, categoryId: number }} param0
   */
  async disableCategory({ terminalId, categoryId }) {
    const res = await posterminalApi.disableCategory(terminalId, categoryId);
    patchTerminalCategories(terminalId, res.categoryIds);
    return res;
  },

  /** Reset to idle state (called on logout / company switch). */
  reset() {
    posterminalAutomat.setState(initialState);
  },
};

function patchTerminalCategories(terminalId, categoryIds) {
  posterminalAutomat.setState({
    terminals: posterminalAutomat.state.terminals.map((t) =>
      t.id === terminalId ? { ...t, categoryIds } : t,
    ),
  });
}

/**
 * Global posterminal state container.
 * Loads automatically when authAutomat reaches 'authed' with a selectedCompanyId.
 *
 * @type {Automat<PosterminalState>}
 */
posterminalAutomat = new Automat(initialState, actions, { name: 'posterminal' });

// Subscribe to auth changes
authAutomat.subscribe((auth) => {
  const companyId = auth.user?.selectedCompanyId;
  if (auth.status === 'authed' && companyId) {
    void posterminalAutomat.actions.load();
  } else if (auth.status === 'anon') {
    posterminalAutomat.actions.reset();
  }
});

// Selectors
export const selectPosterminals = () => posterminalAutomat.state.terminals;
export const selectPosterminalStatus = () => posterminalAutomat.state.status;
export const selectHasPosterminals = () => posterminalAutomat.state.terminals.length > 0;

export default posterminalAutomat;