import { GameTheme } from '../core/types';
import { DEFAULT_THEME } from '../core/config';

/**
 * CustomizationService - handles theming and visual customization
 */
export class CustomizationService {
  private currentTheme: GameTheme;
  private customAssets: Map<string, string> = new Map();
  private themeListeners: Set<(theme: GameTheme) => void> = new Set();

  constructor(defaultTheme: GameTheme = DEFAULT_THEME) {
    this.currentTheme = { ...defaultTheme };
  }

  /**
   * Initialize the service
   */
  async initialize(): Promise<void> {
    // Load saved theme and assets if any
    try {
      // Implementation would load from storage
      // const savedTheme = await storage.getCustomTheme();
      // if (savedTheme) {
      //   this.currentTheme = savedTheme;
      // }
    } catch (error) {
      console.warn('Failed to load saved theme:', error);
    }
  }

  /**
   * Set a new theme
   */
  setTheme(theme: GameTheme): void {
    this.currentTheme = { ...theme };
    this.notifyThemeListeners();
  }

  /**
   * Get current theme
   */
  getCurrentTheme(): GameTheme {
    return { ...this.currentTheme };
  }

  /**
   * Update specific theme properties
   */
  updateTheme(updates: Partial<GameTheme>): void {
    this.currentTheme = {
      ...this.currentTheme,
      ...updates,
      colors: {
        ...this.currentTheme.colors,
        ...updates.colors
      },
      fonts: {
        ...this.currentTheme.fonts,
        ...updates.fonts
      },
      spacing: {
        ...this.currentTheme.spacing,
        ...updates.spacing
      }
    };
    this.notifyThemeListeners();
  }

  /**
   * Set custom assets
   */
  setCustomAssets(assets: Record<string, string>): void {
    Object.entries(assets).forEach(([key, value]) => {
      this.customAssets.set(key, value);
    });
  }

  /**
   * Get custom asset
   */
  getCustomAsset(key: string): string | undefined {
    return this.customAssets.get(key);
  }

  /**
   * Create style object for React Native components
   */
  getStyles() {
    const theme = this.getCurrentTheme();
    
    return {
      container: {
        backgroundColor: theme.colors.background,
        flex: 1
      },
      surface: {
        backgroundColor: theme.colors.surface,
        borderRadius: theme.spacing.md,
        padding: theme.spacing.lg
      },
      primaryButton: {
        backgroundColor: theme.colors.primary,
        borderRadius: theme.spacing.sm,
        paddingHorizontal: theme.spacing.lg,
        paddingVertical: theme.spacing.md
      },
      text: {
        color: theme.colors.text,
        fontFamily: theme.fonts.regular,
        fontSize: 16
      },
      titleText: {
        color: theme.colors.text,
        fontFamily: theme.fonts.title,
        fontSize: 24,
        fontWeight: 'bold'
      }
    };
  }

  /**
   * Subscribe to theme changes
   */
  onThemeChange(callback: (theme: GameTheme) => void): () => void {
    this.themeListeners.add(callback);
    
    // Return unsubscribe function
    return () => {
      this.themeListeners.delete(callback);
    };
  }

  private notifyThemeListeners(): void {
    this.themeListeners.forEach(callback => {
      try {
        callback(this.currentTheme);
      } catch (error) {
        console.warn('Theme listener error:', error);
      }
    });
  }
}