// storage.js — localStorage helpers

const Storage = (() => {
	const KEYS = {
		PLAYER_NAME: "gd_playerName",
		LOBBY_NAME: "gd_lobbyName",
		GAME_STATE: "gd_gameState",
		LEADERBOARD: "gd_leaderboard",
	};

	/**
	 * Safely write a value to localStorage.
	 * Silently fails if storage quota is exceeded or unavailable.
	 * @param {string} key
	 * @param {string} value
	 */
	function _set(key, value) {
		try {
			localStorage.setItem(key, value);
		} catch {
			console.warn(`Storage: could not write key "${key}"`);
		}
	}

	/** @param {string} name */
	function savePlayerName(name) {
		_set(KEYS.PLAYER_NAME, name.trim());
	}

	/** @returns {string} */
	function getPlayerName() {
		return localStorage.getItem(KEYS.PLAYER_NAME) || "Anonymous";
	}

	/** @param {string} name */
	function saveLobbyName(name) {
		_set(KEYS.LOBBY_NAME, name.trim());
	}

	/** @returns {string} */
	function getLobbyName() {
		return localStorage.getItem(KEYS.LOBBY_NAME) || "My Lobby";
	}

	/**
	 * @param {{ scores: number[], totalScore: number, countries: string[] }} state
	 */
	function saveGameState(state) {
		_set(KEYS.GAME_STATE, JSON.stringify(state));
	}

	/**
	 * @returns {{ scores: number[], totalScore: number, countries: string[] } | null}
	 */
	function getGameState() {
		try {
			return JSON.parse(localStorage.getItem(KEYS.GAME_STATE)) || null;
		} catch {
			return null;
		}
	}

	function clearGameState() {
		localStorage.removeItem(KEYS.GAME_STATE);
	}

	/**
	 * Add an entry to the leaderboard and keep the top 20.
	 * @param {{ name: string, totalScore: number, scores: number[], date: string }} entry
	 */
	function saveLeaderboard(entry) {
		const board = getLeaderboard();
		board.push(entry);
		board.sort((a, b) => b.totalScore - a.totalScore);
		_set(KEYS.LEADERBOARD, JSON.stringify(board.slice(0, 20)));
	}

	/**
	 * @returns {{ name: string, totalScore: number, scores: number[], date: string }[]}
	 */
	function getLeaderboard() {
		try {
			return JSON.parse(localStorage.getItem(KEYS.LEADERBOARD)) || [];
		} catch {
			return [];
		}
	}

	function clearLeaderboard() {
		localStorage.removeItem(KEYS.LEADERBOARD);
	}

	return {
		savePlayerName,
		getPlayerName,
		saveLobbyName,
		getLobbyName,
		saveGameState,
		getGameState,
		clearGameState,
		saveLeaderboard,
		getLeaderboard,
		clearLeaderboard,
	};
})();