import { getActions, getContext } from '../lib/actions.js';

const ROOT = 'ask-chatgpt';
const SIMPLE = 'ask-chatgpt-selection';
const PREFIX = 'ask-chatgpt:';
const CONTEXTS = ['selection', 'link', 'page'];
const MENU_KEYS = ['contextMenuMode', 'showContextMenu', 'showTranslate', 'translationMode', 'translationLanguage'];

export function initializeMenus({ browser, load, onAction }) {
  let queue = Promise.resolve();
  let mode = 'off';
  let children = [];
  let menuInstance = 0;
  const enqueue = task => {
    queue = queue.catch(() => {}).then(task);
    return queue;
  };
  const create = properties => new Promise((resolve, reject) => {
    browser.menus.create(properties, () => {
      const error = browser.runtime.lastError;
      if (error) reject(new Error(error.message)); else resolve();
    });
  });
  function rebuild() {
    return enqueue(async () => {
      const settings = await load();
      await browser.menus.removeAll();
      children = [];
      mode = settings.contextMenuMode;
      if (mode === 'off') return;
      if (mode === 'simple') {
        await create({ id: SIMPLE, title: 'Ask ChatGPT', contexts: ['selection'] });
        return;
      }
      await create({ id: ROOT, title: 'Ask ChatGPT', contexts: CONTEXTS });
      for (const kind of ['selection', 'link', 'page']) {
        for (const action of getActions({ kind }, settings)) {
          const id = PREFIX + action.id;
          await create({ id, parentId: ROOT, title: action.title, contexts: CONTEXTS, visible: false });
          children.push({ id, kind });
          if (action.id === 'ask') {
            const separator = PREFIX + 'separator';
            await create({ id: separator, parentId: ROOT, type: 'separator', contexts: CONTEXTS, visible: false });
            children.push({ id: separator, kind });
          }
        }
      }
    });
  }
  browser.storage.onChanged.addListener((changes, area) => {
    if (area === 'sync' && MENU_KEYS.some(key => Object.hasOwn(changes, key))) return rebuild().catch(console.error);
  });
  browser.menus.onHidden.addListener(() => { menuInstance++; });
  browser.menus.onShown.addListener(info => {
    const instance = ++menuInstance;
    // Context labels are available without host access; selectionText/pageUrl
    // are deliberately NOT required until the user invokes an item.
    const contexts = info.contexts ?? [];
    const kind = contexts.includes('selection') ? 'selection'
      : contexts.includes('link') ? 'link'
      : contexts.includes('page') && !info.editable && !contexts.some(c => ['image', 'video', 'audio'].includes(c)) ? 'page' : null;
    return enqueue(async () => {
      if (instance !== menuInstance || mode !== 'advanced') return;
      await Promise.all([
        browser.menus.update(ROOT, { visible: kind !== null }),
        ...children.map(child => browser.menus.update(child.id, { visible: child.kind === kind })),
      ]);
      if (instance === menuInstance) await browser.menus.refresh();
    }).catch(console.error);
  });
  browser.menus.onClicked.addListener(async info => {
    try {
      const settings = await load();
      const context = getContext(info);
      if (!context || settings.contextMenuMode === 'off') return;
      let actionId;
      if (settings.contextMenuMode === 'simple') {
        if (info.menuItemId !== SIMPLE || context.kind !== 'selection') return;
        actionId = 'ask';
      } else {
        const allowed = getActions(context, settings);
        actionId = allowed.find(action => PREFIX + action.id === info.menuItemId)?.id;
        if (!actionId) return;
      }
      await onAction({ actionId, source: context.source, settings });
    } catch { console.error('Could not run context menu action.'); }
  });
  return rebuild();
}