import { ref, computed, watch, nextTick, watchEffect } from "vue";
import { asyncBusFactory } from "@/utils";
import { Dialog } from "bill/index";
import { useViewStack } from "@/hook";

import type { UnwrapRef } from "vue";
import { currentMeta } from "@/router";

const Flags = {
  EDIT: 0b10,
  // 已经保存，是最新的
  NOW: 0b100,
  // 可写模式，用户已登陆
  LOGIN: 0b1000,
} as const;
const mode = ref<number>(Flags.NOW);

export const isEdit = computed(() => !!(mode.value & Flags.EDIT));
export const isLogin = computed(() => !!(mode.value & Flags.LOGIN));
export const isOld = computed(() => !(mode.value & Flags.NOW));
export const isNow = computed(() => !!(mode.value & Flags.NOW));
export const appEl = ref<HTMLDivElement | null>(null);
export const prefix = ref("");

export const defTitle = ref("案件信息");
export const title = computed(() => {
  console.error(currentMeta.value);
  const last =
    currentMeta.value && "sysTitle" in currentMeta.value
      ? currentMeta.value.sysTitle
      : defTitle.value;

  console.error(prefix.value);
  if (prefix.value && last) {
    return prefix.value + " | " + last;
  } else {
    return prefix.value + last;
  }
});
watchEffect(() => (document.title = title.value));

let currentTempIndex = 0;
export const isTemploraryID = (id: string) =>
  id.includes("__currentTempIndex__");
export const createTemploraryID = () =>
  `__currentTempIndex__${currentTempIndex++}`;

export const sysBus = asyncBusFactory<{ save: void; leave: void }>();

// 进入编辑界面
export const enterEdit = (cb?: () => void) => {
  mode.value |= Flags.EDIT;
  cb && sysBus.on("leave", cb);
};

export const enterOld = (cb?: () => void) => {
  mode.value &= ~Flags.NOW;
  cb && sysBus.on("save", cb);
};

// 放弃保存内容
export const giveupSave = () => {
  sysBus.off("save");
  mode.value |= Flags.NOW;
};

// 放弃编辑内容
export const giveupLeave = () => {
  giveupSave();
  sysBus.off("leave");
  mode.value &= ~Flags.EDIT;
};

// 保存
export const save = async () => {
  await sysBus.emit("save");
  giveupSave();
  leave();
};

// 离开
export const leave = async () => {
  if (
    isOld.value &&
    !(await Dialog.confirm("您有操作未保存，确定要退出吗？"))
  ) {
    return;
  }
  await sysBus.emit("leave");
  giveupLeave();
};

export type AutoSetModeSetting<T> = {
  save: () => any;
  leave?: () => any;
  isUpdate?: (newCurrent: UnwrapRef<T>, oldCurrent?: UnwrapRef<T>) => boolean;
  auto?: boolean;
  backup?: () => void;
  recovery?: () => void;
};

let isUnset = false;
export const unSetModelUpdate = (run: () => void) => {
  isUnset = true;
  run();
  nextTick(() => (isUnset = false));
};
export const autoSetModeCallback = <T extends object>(
  current: T,
  setting: AutoSetModeSetting<T>,
  last = true
) => {
  let isLeaveIng = false;
  let isSave = false;
  const leaveCallback =
    (setting.recovery || setting.backup) &&
    (async () => {
      isLeaveIng = true;
      setting.recovery && (await setting.recovery());
      // setting.backup && (await setting.backup());
      setting.leave && (await setting.leave());
      isLeaveIng = false;
    });

  const saveCallback = async () => {
    isSave = true;
    try {
      await setting.save();
      leaveCallback && sysBus.off("leave", leaveCallback, { last });
      setting.backup && setting.backup();
      isSave = false;
    } catch (e) {
      isSave = false;
      throw e;
    }
  };

  const handler = (newv: UnwrapRef<T>, oldv?: UnwrapRef<T>) => {
    if (isSave || isUnset || isLeaveIng) return;
    if (!setting.isUpdate || setting.isUpdate(newv, oldv)) {
      isEdit.value || enterEdit();
      isOld.value || enterOld();
      saveCallback && sysBus.on("save", saveCallback, { last });
    }
    leaveCallback && sysBus.on("leave", leaveCallback, { last });
  };

  return () => {
    setting.backup && setting.backup();
    return watch(current as any, handler, { deep: true });
  };
};

export const useAutoSetMode = <T extends object>(
  current: T,
  setting: AutoSetModeSetting<T>,
  last = true
) => {
  const startWatch = autoSetModeCallback(current, setting, last);
  useViewStack(startWatch);
};