/**
 * Cosmic Garden - Save System
 * Handles localStorage persistence and export/import
 */

const SaveSystem = {
    SAVE_KEY: 'cosmicGardenSave',

    /**
     * Save game to localStorage
     */
    save() {
        const data = JSON.stringify(Game.state);
        localStorage.setItem(this.SAVE_KEY, data);
        console.log('💾 Game saved');
    },

    /**
     * Load game from localStorage
     */
    load() {
        const data = localStorage.getItem(this.SAVE_KEY);
        if (data) {
            try {
                return JSON.parse(data);
            } catch (e) {
                console.error('Failed to parse save:', e);
                return null;
            }
        }
        return null;
    },

    /**
     * Export save as base64 string
     */
    exportSave() {
        const data = btoa(JSON.stringify(Game.state));
        navigator.clipboard.writeText(data).then(() => {
            UI.showNotification('Save copied to clipboard!', 'success');
        }).catch(() => {
            // Fallback for older browsers
            const textarea = document.createElement('textarea');
            textarea.value = data;
            document.body.appendChild(textarea);
            textarea.select();
            document.execCommand('copy');
            document.body.removeChild(textarea);
            UI.showNotification('Save copied to clipboard!', 'success');
        });
    },

    /**
     * Import save from base64 string
     */
    importSave(data) {
        try {
            const parsed = JSON.parse(atob(data));
            
            // Validate save data
            if (!parsed.stardust || !parsed.buildings) {
                throw new Error('Invalid save format');
            }
            
            // Merge with existing state
            Game.state = { ...Game.state, ...parsed };
            Game.state.lastSaveTime = Date.now();
            
            UI.update();
            return true;
        } catch (e) {
            console.error('Failed to import save:', e);
            UI.showNotification('Invalid save data!', 'warning');
            return false;
        }
    },

    /**
     * Clear save data
     */
    clear() {
        localStorage.removeItem(this.SAVE_KEY);
    },

    /**
     * Get last save time
     */
    getLastSaveTime() {
        const data = this.load();
        if (data && data.lastSaveTime) {
            return new Date(data.lastSaveTime);
        }
        return null;
    },

    /**
     * Check if auto-save is available
     */
    hasAutoSave() {
        return !!localStorage.getItem(this.SAVE_KEY);
    }
};

window.SaveSystem = SaveSystem;