import { useEffect, useState } from 'react';
import {
  PREFERENCES_KEY,
  defaultPreferences,
  parsePreferences,
  readPreferences,
  writePreferences,
  type Preferences,
} from './preferences';

interface InitialPreferences {
  preferences: Preferences;
  storageAvailable: boolean;
}

function initializePreferences(): InitialPreferences {
  try {
    const preferences = readPreferences();
    const probeKey = `${PREFERENCES_KEY}:probe`;
    localStorage.setItem(probeKey, '1');
    localStorage.removeItem(probeKey);
    return { preferences, storageAvailable: true };
  } catch {
    return { preferences: { ...defaultPreferences }, storageAvailable: false };
  }
}

export function usePreferences(): [
  Preferences,
  (next: Preferences | ((current: Preferences) => Preferences)) => void,
  boolean,
] {
  const [initial] = useState(initializePreferences);
  const [preferences, setPreferences] = useState<Preferences>(
    initial.preferences
  );

  useEffect(() => {
    try {
      writePreferences(preferences);
    } catch {
      // The UI already reports storage that was unavailable during initialization.
      // A later quota/privacy-mode failure leaves this session's in-memory choices intact.
    }
  }, [preferences]);

  useEffect(() => {
    const handleStorage = (event: StorageEvent) => {
      if (event.key !== PREFERENCES_KEY) return;
      if (event.newValue === null) {
        setPreferences({ ...defaultPreferences });
        return;
      }
      try {
        setPreferences(parsePreferences(JSON.parse(event.newValue)));
      } catch {
        setPreferences({ ...defaultPreferences });
      }
    };
    globalThis.addEventListener('storage', handleStorage);
    return () => globalThis.removeEventListener('storage', handleStorage);
  }, []);

  return [preferences, setPreferences, initial.storageAvailable];
}