import AsyncStorage from '@react-native-async-storage/async-storage';
import type { Event, Station, ReminderSettings } from '@timetoleave/core';

// ── Keys ────────────────────────────────────────────

const EVENTS_KEY = '@timetoleave_events';
const ORIGIN_KEY = '@timetoleave_origin';
const NOTIFICATIONS_KEY = '@timetoleave_notifications';

// ── Default notification settings ─────────────────────

const DEFAULT_NOTIFICATION_SETTINGS: ReminderSettings = {
  bufferMinutes: 30,
  enabled: true,
};

// ── Helpers ───────────────────────────────────────────

function reviveDates(json: string): Event[] {
  try {
    const parsed = JSON.parse(json) as Array<Event & { eventTime: string }>;
    return parsed.map((e) => ({ ...e, eventTime: new Date(e.eventTime) }));
  } catch {
    return [];
  }
}

// ── Events ────────────────────────────────────────────

export async function loadEvents(): Promise<Event[]> {
  const json = await AsyncStorage.getItem(EVENTS_KEY);
  return json ? reviveDates(json) : [];
}

export async function saveEvents(events: Event[]): Promise<void> {
  const json = JSON.stringify(events);
  await AsyncStorage.setItem(EVENTS_KEY, json);
}

export async function addEvent(event: Event): Promise<void> {
  const events = await loadEvents();
  events.push(event);
  await saveEvents(events);
}

export async function removeEvent(id: string, onDone?: () => void): Promise<void> {
  const events = await loadEvents();
  const filtered = events.filter((e) => e.id !== id);
  await saveEvents(filtered);
  onDone?.();
}

// ── Origin Station ────────────────────────────────────

export async function loadOriginStation(): Promise<Station | null> {
  const json = await AsyncStorage.getItem(ORIGIN_KEY);
  return json ? JSON.parse(json) : null;
}

export async function saveOriginStation(station: Station): Promise<void> {
  const json = JSON.stringify(station);
  await AsyncStorage.setItem(ORIGIN_KEY, json);
}

// ── Notification Settings ─────────────────────────────

export async function loadNotificationSettings(): Promise<ReminderSettings> {
  const json = await AsyncStorage.getItem(NOTIFICATIONS_KEY);
  return json ? JSON.parse(json) : DEFAULT_NOTIFICATION_SETTINGS;
}

export async function saveNotificationSettings(
  settings: ReminderSettings,
): Promise<void> {
  const json = JSON.stringify(settings);
  await AsyncStorage.setItem(NOTIFICATIONS_KEY, json);
}