interface HistoryItem {
  timestrap: number; // 記錄時(shí)間戳
  name: string; // 記錄名稱
  redo: string; // 重做Mutation
  undo: string; // 撤銷(xiāo)Mutation
  redoParams: any[]; // 重做Mutation提交參數(shù)
  undoParams: any[]; // 撤銷(xiāo)Mutation提交參數(shù)
}

interface HistoryStatus {
  historys: HistoryItem[]; // 記錄history數(shù)組
  _currentHistory: number; // 當(dāng)前節(jié)點(diǎn)索引
}

import { VuexModule, Module, Mutation, Action } from "vuex-module-decorators";

@Module({ namespaced: true })
export class HistoryModule extends VuexModule<HistoryStatus> implements HistoryStatus {
  /** 
   * 初始化一個(gè)空記錄的原因主要是方便列表操作時(shí)：
   * 當(dāng)用戶點(diǎn)擊最早的一條記錄時(shí)，可以正常撤銷(xiāo)用戶操作的第一步
  **/
  public historys: HistoryItem[] = [
    {
      name: `打開(kāi)`,
      timestrap: Date.now(),
      redo: "",
      redoParams: [],
      undo: "",
      undoParams: [],
    },
  ];
  public _currentHistory: number = 0;

  // getter
  get current(){
    return this._currentHistory;
  }

  // getter
  get historyList(): HistoryItem[] {
    return this.historys || [];
  }

  // 創(chuàng)建歷史記錄
  @Mutation
  public CREATE_HISTORY(payload: HistoryItem) {
    if (this._currentHistory < this.historys.length - 1) {
      this.historys = this.historys.slice(0, this._currentHistory);
    }
    // 由于js的深淺拷貝問(wèn)題，所以在創(chuàng)建時(shí)都需要對(duì)數(shù)據(jù)進(jìn)行深拷貝
    // 想嘗試lodash的clone函數(shù)，但發(fā)現(xiàn)好像JSON.stringify的方式clone應(yīng)該更快的，畢竟我們的數(shù)據(jù)不存在函數(shù)
    // 我這里就先不改了，主要是表達(dá)出思路即可
    this.historys.push(_.cloneDeep(payload));
    this._currentHistory = this.historys.length - 1;
  }

  @Mutation
  public SET_CURRENT_HISTORY(index: number) {
    this._currentHistory = index < 0 ? 0 : index;
  }

  // 重做
  @Action
  public RedoHistory(times: number = 1) {
    let { state, commit } = this.context;
    let historys: HistoryItem[] = state.historys;
    let current: number = state._currentHistory;
    if (current + times >= historys.length) return;
    while (times > 0) {
      current++;
      let history = historys[current];
      if (history) {
        commit(history.redo, ...history.redoParams, { root: true });
      }
      times--;
    }
    commit("SET_CURRENT_HISTORY", current);
  }

  // 撤銷(xiāo)
  @Action
  public UndoHistory(times: number = 1) {
    let { state, commit } = this.context;
    let historys: HistoryItem[] = state.historys;
    let current: number = state._currentHistory;
    if (current - times < 0) return;
    while (times > 0) {
      let history = historys[current];
      if (history) {
        commit(history.undo, ...history.undoParams, { root: true });
      }
      times--;
      current--;
    }
    commit("SET_CURRENT_HISTORY", current);
  }
}

@Mutation
public CREATE_PAGE(payload: { page: PageItem; index: number }) {
  this.pages.splice(payload.index, 0, _.cloneDeep(payload.page));
  this._currentPage = this.pages.length - 1;
}

@Mutation
public REMOVE_PAGE(id: string) {
  let index = this.pages.findIndex((p) => p.id == id);
  index > -1 && this.pages.splice(index, 1);
  if (this._currentPage == index) {
    this._currentPage = this.pages.length > 0 ? 0 : -1;
  }
}

// 包裝創(chuàng)建頁(yè)面函數(shù)
@Action
public CreatePage(type: "page" | "dialog") {
  let { state, commit } = this.context;
  
  // 記錄保存即將創(chuàng)建的頁(yè)面
  let id = _.uniqueId(type) + Date.now();
  let pageName = pageType[type];
  let page: PageItem = {
    id,
    name: `${pageName}${state.pages.length + 1}`,
    type,
    layers: [],
    style: { width: 720, height: 1280 },
  };

  //創(chuàng)建歷史記錄
  let history: HistoryItem = {
    name: `創(chuàng)建${pageName}`,
    timestrap: Date.now(),
    redo: "Page/CREATE_PAGE",
    redoParams: [{ index: state.pages.length - 1, page }],
    undo: "Page/REMOVE_PAGE",
    undoParams: [id],
  };
  // 保存記錄此歷史記錄
  commit("Histroy/CREATE_HISTORY", history, { root: true });

  commit(history.redo, ...history.redoParams, { root: true });
}

@Action
public RemovePage(id: string) {
  // 記錄保存現(xiàn)場(chǎng)狀態(tài)
  let index = this.pages.findIndex((p) => p.id == id);
  if (index < 0) return;
  let page: PageItem = this.context.state.pages[index];

  //創(chuàng)建歷史記錄
  let history: HistoryItem = {
    name: `刪除 ${page.name}`,
    timestrap: Date.now(),
    redo: "Page/REMOVE_PAGE",
    redoParams: [id],
    undo: "Page/CREATE_PAGE",
    undoParams: [{ page, index }],
  };

  // 保存記錄此歷史記錄
  this.context.commit("Histroy/CREATE_HISTORY", history, { root: true });
  this.context.commit(history.redo, ...history.redoParams, { root: true });
}

  private create(type: "page" | "dialog") {
    this.$store.dispatch("Page/CreatePage", type);
  }

  private remove(id: number) {
    this.$store.dispatch("Page/RemovePage", id);
  }

private mounted() {
    let self = this;
    hotkeys("ctrl+z", function (event, handler) {
      self.$store.dispatch("History/UndoHistory");
    });
    hotkeys("ctrl+y", function (event, handler) {
      self.$store.dispatch("History/RedoHistory");
    });
  }