import { openDB, DBSchema, IDBPDatabase } from "idb";
import { type CalendarEvent } from "./types";

interface ICalDB extends DBSchema {
	events: {
		key: string;
		value: CalendarEvent;
	};
}

let dbPromise: Promise<IDBPDatabase<ICalDB>> | null = null;

async function initDB() {
	return openDB<ICalDB>("icalPWA", 1, {
		upgrade(db) {
			if (!db.objectStoreNames.contains("events")) {
				db.createObjectStore("events", { keyPath: "id" });
			}
		},
	});
}

// Get the database in a browser-safe way
export async function getDB() {
	if (typeof window === "undefined") return null;
	if (!dbPromise) {
		dbPromise = initDB();
	}
	return dbPromise;
}

// CRUD operations — all SSR-safe
export async function getAllEvents() {
	const db = await getDB();
	if (!db) return [];
	return db.getAll("events");
}

export async function addEvent(event: ICalDB["events"]["value"]) {
	const db = await getDB();
	if (!db) return;
	return db.put("events", event);
}

export async function deleteEvent(id: string) {
	const db = await getDB();
	if (!db) return;
	return db.delete("events", id);
}

export async function clearEvents() {
	const db = await getDB();
	if (!db) return;
	return db.clear("events");
}