import { createBrowserHistory, History } from "history";
import { computed, configure, when } from "mobx";
import { RouterStore, syncHistoryWithStore } from "mobx-react-router";

import { WebSocketRpcClient } from "@client/sprinklersRpc/WebSocketRpcClient";
import HttpApi from "@client/state/HttpApi";
import { UiStore } from "@client/state/UiStore";
import { UserStore } from "@client/state/UserStore";
import ApiError from "@common/ApiError";
import { ErrorCode } from "@common/ErrorCode";
import log from "@common/logger";
import { DefaultEvents, TypedEventEmitter } from "@common/TypedEventEmitter";

interface AppEvents extends DefaultEvents {
  checkToken(): void;
  hasToken(): void;
}

export default class AppState extends TypedEventEmitter<AppEvents> {
  history: History = createBrowserHistory();
  routerStore = new RouterStore();
  uiStore = new UiStore();
  userStore = new UserStore();
  httpApi = new HttpApi();
  tokenStore = this.httpApi.tokenStore;
  sprinklersRpc = new WebSocketRpcClient(this.tokenStore);

  constructor() {
    super();
    this.sprinklersRpc.on("newUserData", this.userStore.receiveUserData);
    this.sprinklersRpc.on("tokenError", this.clearToken);
    this.httpApi.on("tokenGranted", () => this.emit("hasToken"));
    this.httpApi.on("tokenError", this.clearToken);

    this.on("checkToken", this.doCheckToken);

    this.on("hasToken", () => {
      when(() => !this.tokenStore.accessToken.isValid, this.checkToken);
      this.sprinklersRpc.start();
    });
  }

  @computed
  get isLoggedIn() {
    return this.tokenStore.accessToken.isValid;
  }

  async start() {
    configure({
      enforceActions: "observed"
    });

    syncHistoryWithStore(this.history, this.routerStore);
    await this.tokenStore.loadLocalStorage();

    await this.checkToken();
  }

  clearToken = (err?: any) => {
    this.tokenStore.clearAccessToken();
    this.checkToken();
  };

  checkToken = () => {
    this.emit("checkToken");
  };

  private doCheckToken = async () => {
    const { accessToken, refreshToken } = this.tokenStore;
    accessToken.updateCurrentTime();
    if (accessToken.isValid) {
      // if the access token is valid, we are good
      this.emit("hasToken");
      return;
    }
    if (!refreshToken.isValid) {
      // if the refresh token is not valid, need to login again
      this.history.push("/login");
      return;
    }
    try {
      await this.httpApi.grantRefresh();
      this.emit("hasToken");
    } catch (err) {
      if (err instanceof ApiError && err.code === ErrorCode.BadToken) {
        log.warn({ err }, "refresh is bad for some reason, erasing");
        this.tokenStore.clearAll();
        this.history.push("/login");
      } else {
        log.error({ err }, "could not refresh access token");
        // TODO: some kind of error page?
      }
    }
  };
}