// Production - The Idle Game: Backend Synchronization & Authentication

const TOKEN_KEY = 'production_auth_token';
const USERNAME_KEY = 'production_username';

export class SyncManager {
    constructor(stateManager) {
        this.sm = stateManager;
        this.token = localStorage.getItem(TOKEN_KEY) || null;
        this.username = localStorage.getItem(USERNAME_KEY) || null;
        this.isSyncing = false;
        this.pendingActions = [];
        this.debounceTimer = null;
    }

    isLoggedIn() {
        return !!this.token;
    }

    getUsername() {
        return this.username || 'Executive Guest';
    }

    setAuth(token, username) {
        this.token = token;
        this.username = username;
        localStorage.setItem(TOKEN_KEY, token);
        localStorage.setItem(USERNAME_KEY, username);
    }

    logout() {
        this.token = null;
        this.username = null;
        localStorage.removeItem(TOKEN_KEY);
        localStorage.removeItem(USERNAME_KEY);
    }

    queueAction(action) {
        this.pendingActions.push(action);
        clearTimeout(this.debounceTimer);
        this.debounceTimer = setTimeout(() => this.flush(), 1000);
    }

    async flush() {
        if (!this.token || this.isSyncing || this.pendingActions.length === 0) return;
        this.isSyncing = true;
        const actionsToSend = [...this.pendingActions];
        this.pendingActions = [];

        try {
            const res = await fetch('/api/game/tick', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${this.token}`
                },
                body: JSON.stringify({
                    seq: Date.now(),
                    actions: actionsToSend,
                    client_tick: Date.now() / 1000
                })
            });

            if (!res.ok) {
                // If unauthorized, clear token
                if (res.status === 401) this.logout();
                // Return unsent actions to queue
                this.pendingActions.unshift(...actionsToSend);
            }
        } catch (err) {
            console.warn('Sync failed (will retry):', err);
            this.pendingActions.unshift(...actionsToSend);
        } finally {
            this.isSyncing = false;
        }
    }

    async fetchCloudState() {
        if (!this.token) return null;
        try {
            const res = await fetch('/api/game/state', {
                headers: { 'Authorization': `Bearer ${this.token}` }
            });
            if (res.ok) {
                const data = await res.json();
                return data.save_data || null;
            }
        } catch (err) {
            console.error('Error fetching cloud state:', err);
        }
        return null;
    }

    async login(username, password) {
        const res = await fetch('/api/auth/login', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ username, password })
        });
        const data = await res.json();
        if (!res.ok) throw new Error(data.detail || 'Login failed');
        this.setAuth(data.token, data.username);
        return data;
    }

    async saveCloudState(saveData) {
        if (!this.token) return false;
        try {
            const res = await fetch('/api/game/save', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${this.token}`
                },
                body: JSON.stringify({ save_data: saveData })
            });
            return res.ok;
        } catch (err) {
            console.error('Error saving cloud state:', err);
            return false;
        }
    }

    async register(username, password, website_hp = '') {
        const res = await fetch('/api/auth/register', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ username, password, website_hp })
        });
        const data = await res.json();
        if (!res.ok) throw new Error(data.detail || 'Registration failed');
        this.setAuth(data.token, data.username);
        return data;
    }
}