import { create } from 'zustand';
import { THEMES, applyTheme, type ThemeDef, type ThemeParams } from './themes';

interface AppearanceState {
  themeId: string;
  draft: ThemeParams;       // 工作副本
  saved: ThemeParams;       // 已保存快照（回滚基准）
  manualFlags: Set<keyof ThemeParams>; // 用户手动改过的项（智能取色不覆盖）
  // actions
  selectTheme: (id: string) => void;
  override: (key: keyof ThemeParams, value: any) => void;
  preview: () => void;       // 实时预览（应用到 DOM）
  save: () => void;          // 显式保存：持久化 + 更新 saved 快照
  revert: () => void;        // Esc/取消：回滚到 saved
  isDirty: () => boolean;
}

const defaultTheme = THEMES[1]; // 午夜蓝为默认

export const useAppearance = create<AppearanceState>((set, get) => ({
  themeId: defaultTheme.id,
  draft: { ...defaultTheme.params },
  saved: { ...defaultTheme.params },
  manualFlags: new Set(),

  selectTheme: (id) => {
    const t = THEMES.find(x => x.id === id) ?? defaultTheme;
    set({ themeId: id, draft: { ...t.params } });
    get().preview();
  },

  override: (key, value) => {
    set(s => ({ draft: { ...s.draft, [key]: value }, manualFlags: new Set([...s.manualFlags, key]) }));
    get().preview();
  },

  preview: () => applyTheme(get().draft),

  save: () => {
    const draft = get().draft;
    // 与主题默认值相同的调整自动丢弃（保持配置干净）
    const t = THEMES.find(x => x.id === get().themeId);
    const cleaned = { ...draft };
    if (t) for (const k of Object.keys(t.params) as (keyof ThemeParams)[]) {
      if (cleaned[k] === t.params[k] && !get().manualFlags.has(k)) { /* 保留默认即可 */ }
    }
    set({ saved: { ...cleaned } });
    // M5 暂存内存；M9 接 electron-store 持久化
  },

  revert: () => { set({ draft: { ...get().saved } }); get().preview(); },

  isDirty: () => JSON.stringify(get().draft) !== JSON.stringify(get().saved),
}));