import { create } from 'zustand';
import { IPC } from '@hunter/shared';
import type { TreeNode, VaultMeta, DocMeta, ReadDocResult } from '@hunter/shared';
import { invoke } from './ipc-client';
import { useTabs } from './features/tabs/tab-store';

export type SaveState = 'saved' | 'saving' | 'error';

interface EditorState {
  vault: VaultMeta | null;
  tree: TreeNode[];
  treeLoading: boolean;
  currentPath: string | null;
  title: string;
  body: string;
  meta: DocMeta;
  saveState: SaveState;
  docMtime: number; // FR-S6：已加载文档的 mtime，用于检测外部改动
  tagFilter: string[]; // FR-R7：选中标签列表，FileTree 据此 AND 过滤
  // actions
  loadVault: () => Promise<void>;
  loadTree: () => Promise<void>;
  openDoc: (path: string) => Promise<void>;
  setBody: (body: string) => void;
  setMeta: (meta: DocMeta) => void;
  addTag: (tag: string) => void;
  removeTag: (tag: string) => void;
  toggleStar: () => void;
  addLink: (link: string) => void;
  removeLink: (link: string) => void;
  saveNow: () => Promise<void>;
  reloadDoc: () => Promise<boolean>; // FR-S6：重新加载——检测 mtime 变化，有未保存改动时返回 false 需确认
  resetEditor: () => void;                          // FR-V6: 切库时重置编辑区
  syncCurrentPath: (oldPath: string, newPath: string) => void; // FR-T7: 重命名/移动后同步当前文档路径
}

// 简单的每文档保存队列（M1 单文档编辑）
let saveTimer: ReturnType<typeof setTimeout> | null = null;

export const useStore = create<EditorState>((set, get) => ({
  vault: null,
  tree: [],
  treeLoading: false,
  currentPath: null,
  title: '',
  body: '',
  meta: {},
  saveState: 'saved',
  tagFilter: [],
  docMtime: 0,

  loadVault: async () => {
    const vault = await invoke(IPC.vaultList, undefined as never);
    set({ vault });
  },

  loadTree: async () => {
    set({ treeLoading: true });
    try {
      const tree = await invoke(IPC.treeList, undefined as never);
      set({ tree, treeLoading: false });
    } catch (e) {
      set({ treeLoading: false });
      console.error('loadTree failed', e);
    }
  },

  openDoc: async (path: string) => {
    // 切换前冲刷当前文档——先同步编辑器内容到 store 再保存
    window.dispatchEvent(new CustomEvent('dsh-flush-body'));
    void get().saveNow();
    const doc: ReadDocResult = await invoke(IPC.docRead, { path });
    set({ currentPath: path, body: doc.body, meta: doc.meta, title: doc.meta.title ?? path.split('/').pop()!.replace(/\.md$/, ''), saveState: 'saved', docMtime: doc.mtime });
    // 同步到标签页（如已存在则激活，否则新建）
    useTabs.getState().openTab(path);
  },

  setMeta: (meta: DocMeta) => { set({ meta }); get().saveNow(); },
  addTag: (tag: string) => {
    const tags = [...(get().meta.tags ?? []), tag].filter((t, i, a) => a.indexOf(t) === i);
    set({ meta: { ...get().meta, tags } });
    get().saveNow();
  },
  removeTag: (tag: string) => {
    const tags = (get().meta.tags ?? []).filter(t => t !== tag);
    set({ meta: { ...get().meta, tags } });
    get().saveNow();
  },
  toggleStar: () => {
    set({ meta: { ...get().meta, star: !get().meta.star } });
    get().saveNow();
  },
  addLink: (link: string) => {
    const links = [...(get().meta.links ?? []), link].filter((l, i, a) => a.indexOf(l) === i);
    set({ meta: { ...get().meta, links } });
    get().saveNow();
  },
  removeLink: (link: string) => {
    const links = (get().meta.links ?? []).filter(l => l !== link);
    set({ meta: { ...get().meta, links } });
    get().saveNow();
  },
  setBody: (body: string) => {
    set({ body, saveState: 'saving' });
    // FR-S1：防抖自动保存——间隔读 settings.autoSaveInterval（秒→毫秒）
    if (saveTimer) clearTimeout(saveTimer);
    const interval = (() => { try { const s = JSON.parse(localStorage.getItem('dsh-settings') ?? '{}'); return (s.autoSaveInterval ?? 3) * 1000; } catch { return 3000; } })();
    saveTimer = setTimeout(() => { get().saveNow(); }, interval);
  },

  saveNow: async () => {
    if (saveTimer) { clearTimeout(saveTimer); saveTimer = null; }
    const { currentPath, body, meta } = get();
    if (!currentPath) return;
    try {
      await invoke(IPC.docWrite, { path: currentPath, meta, body });
      set({ saveState: 'saved' });
    } catch (e) {
      set({ saveState: 'error' });
      console.error('save failed', e);
    }
  },

  // FR-S6：重新加载文档——检测 mtime 变化，有未保存改动时返回 false 需确认
  reloadDoc: async () => {
    const { currentPath, docMtime, saveState } = get();
    if (!currentPath) return false;
    try {
      const doc: ReadDocResult = await invoke(IPC.docRead, { path: currentPath });
      if (doc.mtime === docMtime) return true; // 未变
      if (saveState !== 'saved') return false; // 有未保存改动，需确认
      set({ body: doc.body, meta: doc.meta, docMtime: doc.mtime, saveState: 'saved' });
      return true;
    } catch { return false; }
  },

  resetEditor: () => { set({ currentPath: null, title: '', body: '', meta: {}, saveState: 'saved', docMtime: 0 }); },

  syncCurrentPath: (oldPath, newPath) => {
    const { currentPath } = get();
    if (!currentPath) return;
    if (currentPath === oldPath) { set({ currentPath: newPath }); return; }
    if (oldPath && currentPath.startsWith(oldPath + '/')) set({ currentPath: newPath + currentPath.slice(oldPath.length) });
  },
}));

// FR-S6：暴露 store 供 E2E 验证
if (typeof window !== 'undefined') (window as any).__STORE__ = useStore;