Split front and back end.

1 files changed, 393 insertions, 0 deletions

diff --git a/FrontEnd/src/app/services/user.ts b/FrontEnd/src/app/services/user.ts
new file mode 100644
index 00000000..f253fc19
--- /dev/null
+++ b/FrontEnd/src/app/services/user.ts
@@ -0,0 +1,393 @@
+import React, { useState, useEffect } from "react";
+import { BehaviorSubject, Observable, from } from "rxjs";
+import { map, filter } from "rxjs/operators";
+
+import { UiLogicError } from "@/common";
+import { convertError } from "@/utilities/rxjs";
+
+import { HttpNetworkError, BlobWithEtag, NotModified } from "@/http/common";
+import {
+  getHttpTokenClient,
+  HttpCreateTokenBadCredentialError,
+} from "@/http/token";
+import {
+  getHttpUserClient,
+  HttpUserNotExistError,
+  HttpUser,
+} from "@/http/user";
+
+import { dataStorage, throwIfNotNetworkError } from "./common";
+import { DataHub } from "./DataHub";
+import { pushAlert } from "./alert";
+
+export type User = HttpUser;
+
+export interface UserAuthInfo {
+  username: string;
+  administrator: boolean;
+}
+
+export interface UserWithToken extends User {
+  token: string;
+}
+
+export interface LoginCredentials {
+  username: string;
+  password: string;
+}
+
+export class BadCredentialError {
+  message = "login.badCredential";
+}
+
+const USER_STORAGE_KEY = "currentuser";
+
+export class UserService {
+  private userSubject = new BehaviorSubject<UserWithToken | null | undefined>(
+    undefined
+  );
+
+  get user$(): Observable<UserWithToken | null | undefined> {
+    return this.userSubject;
+  }
+
+  get currentUser(): UserWithToken | null | undefined {
+    return this.userSubject.value;
+  }
+
+  async checkLoginState(): Promise<UserWithToken | null> {
+    if (this.currentUser !== undefined) {
+      console.warn("Already checked user. Can't check twice.");
+    }
+
+    const savedUser = await dataStorage.getItem<UserWithToken | null>(
+      USER_STORAGE_KEY
+    );
+
+    if (savedUser == null) {
+      this.userSubject.next(null);
+      return null;
+    }
+
+    this.userSubject.next(savedUser);
+
+    const savedToken = savedUser.token;
+    try {
+      const res = await getHttpTokenClient().verify({ token: savedToken });
+      const user: UserWithToken = { ...res.user, token: savedToken };
+      await dataStorage.setItem<UserWithToken>(USER_STORAGE_KEY, user);
+      this.userSubject.next(user);
+      pushAlert({
+        type: "success",
+        message: {
+          type: "i18n",
+          key: "user.welcomeBack",
+        },
+      });
+      return user;
+    } catch (error) {
+      if (error instanceof HttpNetworkError) {
+        pushAlert({
+          type: "danger",
+          message: { type: "i18n", key: "user.verifyTokenFailedNetwork" },
+        });
+        return savedUser;
+      } else {
+        await dataStorage.removeItem(USER_STORAGE_KEY);
+        this.userSubject.next(null);
+        pushAlert({
+          type: "danger",
+          message: { type: "i18n", key: "user.verifyTokenFailed" },
+        });
+        return null;
+      }
+    }
+  }
+
+  async login(
+    credentials: LoginCredentials,
+    rememberMe: boolean
+  ): Promise<void> {
+    if (this.currentUser) {
+      throw new UiLogicError("Already login.");
+    }
+    try {
+      const res = await getHttpTokenClient().create({
+        ...credentials,
+        expire: 30,
+      });
+      const user: UserWithToken = {
+        ...res.user,
+        token: res.token,
+      };
+      if (rememberMe) {
+        await dataStorage.setItem<UserWithToken>(USER_STORAGE_KEY, user);
+      }
+      this.userSubject.next(user);
+    } catch (e) {
+      if (e instanceof HttpCreateTokenBadCredentialError) {
+        throw new BadCredentialError();
+      } else {
+        throw e;
+      }
+    }
+  }
+
+  async logout(): Promise<void> {
+    if (this.currentUser === undefined) {
+      throw new UiLogicError("Please check user first.");
+    }
+    if (this.currentUser === null) {
+      throw new UiLogicError("No login.");
+    }
+    await dataStorage.removeItem(USER_STORAGE_KEY);
+    this.userSubject.next(null);
+  }
+
+  changePassword(
+    oldPassword: string,
+    newPassword: string
+  ): Observable<unknown> {
+    if (this.currentUser == undefined) {
+      throw new UiLogicError("Not login or checked now, can't log out.");
+    }
+    const $ = from(
+      getHttpUserClient().changePassword(
+        {
+          oldPassword,
+          newPassword,
+        },
+        this.currentUser.token
+      )
+    );
+    $.subscribe(() => {
+      void this.logout();
+    });
+    return $;
+  }
+}
+
+export const userService = new UserService();
+
+export function useRawUser(): UserWithToken | null | undefined {
+  const [user, setUser] = useState<UserWithToken | null | undefined>(
+    userService.currentUser
+  );
+  useEffect(() => {
+    const subscription = userService.user$.subscribe((u) => setUser(u));
+    return () => {
+      subscription.unsubscribe();
+    };
+  });
+  return user;
+}
+
+export function useUser(): UserWithToken | null {
+  const [user, setUser] = useState<UserWithToken | null>(() => {
+    const initUser = userService.currentUser;
+    if (initUser === undefined) {
+      throw new UiLogicError(
+        "This is a logic error in user module. Current user can't be undefined in useUser."
+      );
+    }
+    return initUser;
+  });
+  useEffect(() => {
+    const sub = userService.user$.subscribe((u) => {
+      if (u === undefined) {
+        throw new UiLogicError(
+          "This is a logic error in user module. User emitted can't be undefined later."
+        );
+      }
+      setUser(u);
+    });
+    return () => {
+      sub.unsubscribe();
+    };
+  });
+  return user;
+}
+
+export function useUserLoggedIn(): UserWithToken {
+  const user = useUser();
+  if (user == null) {
+    throw new UiLogicError("You assert user has logged in but actually not.");
+  }
+  return user;
+}
+
+export function checkLogin(): UserWithToken {
+  const user = userService.currentUser;
+  if (user == null) {
+    throw new UiLogicError("You must login to perform the operation.");
+  }
+  return user;
+}
+
+export class UserNotExistError extends Error {}
+
+export class UserInfoService {
+  saveUser(user: HttpUser): void {
+    const key = user.username;
+    void this._userHub.optionalInitLineWithSyncAction(key, async (line) => {
+      await this.doSaveUser(user);
+      line.next({ user, type: "synced" });
+    });
+  }
+
+  saveUsers(users: HttpUser[]): void {
+    return users.forEach((user) => this.saveUser(user));
+  }
+
+  private getCachedUser(username: string): Promise<User | null> {
+    return dataStorage.getItem<HttpUser | null>(`user.${username}`);
+  }
+
+  private doSaveUser(user: HttpUser): Promise<void> {
+    return dataStorage.setItem<HttpUser>(`user.${user.username}`, user).then();
+  }
+
+  syncUser(username: string): Promise<void> {
+    return this._userHub.getLineOrCreate(username).sync();
+  }
+
+  private _userHub = new DataHub<
+    string,
+    | { user: User; type: "cache" | "synced" | "offline" }
+    | { user?: undefined; type: "notexist" | "offline" }
+  >({
+    sync: async (key, line) => {
+      if (line.value == undefined) {
+        const cache = await this.getCachedUser(key);
+        if (cache != null) {
+          line.next({ user: cache, type: "cache" });
+        }
+      }
+
+      try {
+        const res = await getHttpUserClient().get(key);
+        await this.doSaveUser(res);
+        line.next({ user: res, type: "synced" });
+      } catch (e) {
+        if (e instanceof HttpUserNotExistError) {
+          line.next({ type: "notexist" });
+        } else {
+          const cache = await this.getCachedUser(key);
+          line.next({ user: cache ?? undefined, type: "offline" });
+          throwIfNotNetworkError(e);
+        }
+      }
+    },
+  });
+
+  getUser$(username: string): Observable<User> {
+    return this._userHub.getObservable(username).pipe(
+      map((state) => state?.user),
+      filter((user): user is User => user != null)
+    );
+  }
+
+  private getCachedAvatar(username: string): Promise<BlobWithEtag | null> {
+    return dataStorage.getItem<BlobWithEtag | null>(`user.${username}.avatar`);
+  }
+
+  private saveAvatar(username: string, data: BlobWithEtag): Promise<void> {
+    return dataStorage
+      .setItem<BlobWithEtag>(`user.${username}.avatar`, data)
+      .then();
+  }
+
+  syncAvatar(username: string): Promise<void> {
+    return this._avatarHub.getLineOrCreate(username).sync();
+  }
+
+  private _avatarHub = new DataHub<
+    string,
+    | { data: Blob; type: "cache" | "synced" | "offline" }
+    | { data?: undefined; type: "notexist" | "offline" }
+  >({
+    sync: async (key, line) => {
+      const cache = await this.getCachedAvatar(key);
+      if (line.value == null) {
+        if (cache != null) {
+          line.next({ data: cache.data, type: "cache" });
+        }
+      }
+
+      if (cache == null) {
+        try {
+          const avatar = await getHttpUserClient().getAvatar(key);
+          await this.saveAvatar(key, avatar);
+          line.next({ data: avatar.data, type: "synced" });
+        } catch (e) {
+          line.next({ type: "offline" });
+          throwIfNotNetworkError(e);
+        }
+      } else {
+        try {
+          const res = await getHttpUserClient().getAvatar(key, cache.etag);
+          if (res instanceof NotModified) {
+            line.next({ data: cache.data, type: "synced" });
+          } else {
+            const avatar = res;
+            await this.saveAvatar(key, avatar);
+            line.next({ data: avatar.data, type: "synced" });
+          }
+        } catch (e) {
+          line.next({ data: cache.data, type: "offline" });
+          throwIfNotNetworkError(e);
+        }
+      }
+    },
+  });
+
+  getAvatar$(username: string): Observable<Blob> {
+    return this._avatarHub.getObservable(username).pipe(
+      map((state) => state.data),
+      filter((blob): blob is Blob => blob != null)
+    );
+  }
+
+  getUserInfo(username: string): Observable<User> {
+    return from(getHttpUserClient().get(username)).pipe(
+      convertError(HttpUserNotExistError, UserNotExistError)
+    );
+  }
+
+  async setAvatar(username: string, blob: Blob): Promise<void> {
+    const user = checkLogin();
+    await getHttpUserClient().putAvatar(username, blob, user.token);
+    this._avatarHub.getLine(username)?.next({ data: blob, type: "synced" });
+  }
+
+  async setNickname(username: string, nickname: string): Promise<void> {
+    const user = checkLogin();
+    return getHttpUserClient()
+      .patch(username, { nickname }, user.token)
+      .then((user) => {
+        this.saveUser(user);
+      });
+  }
+}
+
+export const userInfoService = new UserInfoService();
+
+export function useAvatar(username?: string): Blob | undefined {
+  const [state, setState] = React.useState<Blob | undefined>(undefined);
+  React.useEffect(() => {
+    if (username == null) {
+      setState(undefined);
+      return;
+    }
+
+    const subscription = userInfoService
+      .getAvatar$(username)
+      .subscribe((blob) => {
+        setState(blob);
+      });
+    return () => {
+      subscription.unsubscribe();
+    };
+  }, [username]);
+  return state;
+}