/**
 * Lightweight State Manager for Short Track Dashboard
 * Replaces global variables with reactive state + event system
 */
class AppState {
    constructor() {
        this._state = {};
        this._listeners = {};
    }

    get(key) { return this._state[key]; }

    set(key, value) {
        const old = this._state[key];
        this._state[key] = value;
        if (old !== value && this._listeners[key]) {
            this._listeners[key].forEach(fn => fn(value, old));
        }
    }

    on(key, fn) {
        if (!this._listeners[key]) this._listeners[key] = [];
        this._listeners[key].push(fn);
        return () => {
            this._listeners[key] = this._listeners[key].filter(f => f !== fn);
        };
    }

    batch(updates) {
        Object.entries(updates).forEach(([k, v]) => this.set(k, v));
    }
}

// Global singleton
const store = new AppState();

// Initialize default state
store.batch({
    athletes: [],
    selectedAthlete: null,
    selectedEvent: null,
    currentUser: null,
    dashboardData: null,
    currentMatchId: null,
    trainingTypes: [],
    profileAthlete: null,
    profileTab: 'overview',
    profileData: null,
    editingMessageId: null,
    replyingToId: null,
    liveRaceGroups: [],
});

// Convenience: expose as global for backward compat
window.store = store;