/**
 * Player Identifier Management
 * 
 * Generates and manages a unique player identifier (UUID) that is stored
 * in localStorage. This identifier is used to sync game states across
 * different domains (hoerdle.de and hördle.de).
 */

const STORAGE_KEY = 'hoerdle_player_id';

/**
 * Generate a UUID v4
 */
function generatePlayerId(): string {
    // UUID v4 format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
        const r = Math.random() * 16 | 0;
        const v = c === 'x' ? r : (r & 0x3 | 0x8);
        return v.toString(16);
    });
}

/**
 * Get or create a player identifier
 * 
 * If no identifier exists in localStorage, a new UUID is generated and stored.
 * The same identifier is used across all domains (hoerdle.de and hördle.de).
 * 
 * @returns Player identifier (UUID v4)
 */
export function getOrCreatePlayerId(): string {
    if (typeof window === 'undefined') {
        // Server-side: return empty string (not used on server)
        return '';
    }
    
    let playerId = localStorage.getItem(STORAGE_KEY);
    if (!playerId) {
        playerId = generatePlayerId();
        localStorage.setItem(STORAGE_KEY, playerId);
    }
    return playerId;
}

/**
 * Get the current player identifier without creating a new one
 * 
 * @returns Player identifier or null if not set
 */
export function getPlayerId(): string | null {
    if (typeof window === 'undefined') {
        return null;
    }
    return localStorage.getItem(STORAGE_KEY);
}