import { create } from 'zustand';
import AsyncStorage from '@react-native-async-storage/async-storage';

const STORAGE_KEY = '@rebreak/chat-backgrounds';

// Pro-Chat-Hintergrund (lokal, gerätegebunden). Default = 'clean' (Insta-Style,
// solider Theme-BG ohne Muster). 'pattern' = der WhatsApp-artige SVG-Symbol-BG.
export type ChatBgStyle = 'clean' | 'pattern';
export const DEFAULT_CHAT_BG: ChatBgStyle = 'clean';

type ChatBackgroundState = {
  // partnerId → Stil. Fehlt der Key → DEFAULT_CHAT_BG.
  backgrounds: Record<string, ChatBgStyle>;
  init: () => Promise<void>;
  setBackground: (partnerId: string, style: ChatBgStyle) => Promise<void>;
};

export const useChatBackgroundStore = create<ChatBackgroundState>((set, get) => ({
  backgrounds: {},

  init: async () => {
    try {
      const raw = await AsyncStorage.getItem(STORAGE_KEY);
      if (raw) set({ backgrounds: JSON.parse(raw) });
    } catch {
      // non-fatal — Default-Clean greift
    }
  },

  setBackground: async (partnerId, style) => {
    const next = { ...get().backgrounds, [partnerId]: style };
    set({ backgrounds: next });
    try {
      await AsyncStorage.setItem(STORAGE_KEY, JSON.stringify(next));
    } catch {
      // non-fatal
    }
  },
}));