summaryrefslogtreecommitdiff
path: root/packages/demobank-ui/src/hooks/backend.ts
blob: 863b47bf33a31f4506a2c9972f107c64123e1c65 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/*
 This file is part of GNU Taler
 (C) 2022 Taler Systems S.A.

 GNU Taler is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

import {
  AccessToken,
  Codec,
  buildCodecForObject,
  buildCodecForUnion,
  canonicalizeBaseUrl,
  codecForBoolean,
  codecForConstString,
  codecForString,
} from "@gnu-taler/taler-util";
import {
  buildStorageKey,
  useLocalStorage
} from "@gnu-taler/web-util/browser";
import { useSWRConfig } from "swr";

/**
 * Has the information to reach and
 * authenticate at the bank's backend.
 */
export type BackendState = LoggedIn | LoggedOut | Expired;

interface LoggedIn {
  status: "loggedIn";
  isUserAdministrator: boolean;
  username: string;
  token: AccessToken;
}
interface Expired {
  status: "expired";
  isUserAdministrator: boolean;
  username: string;
}
interface LoggedOut {
  status: "loggedOut";
}

export const codecForBackendStateLoggedIn = (): Codec<LoggedIn> =>
  buildCodecForObject<LoggedIn>()
    .property("status", codecForConstString("loggedIn"))
    .property("username", codecForString())
    .property("token", codecForString() as Codec<AccessToken>)
    .property("isUserAdministrator", codecForBoolean())
    .build("BackendState.LoggedIn");

export const codecForBackendStateExpired = (): Codec<Expired> =>
  buildCodecForObject<Expired>()
    .property("status", codecForConstString("expired"))
    .property("username", codecForString())
    .property("isUserAdministrator", codecForBoolean())
    .build("BackendState.Expired");

export const codecForBackendStateLoggedOut = (): Codec<LoggedOut> =>
  buildCodecForObject<LoggedOut>()
    .property("status", codecForConstString("loggedOut"))
    .build("BackendState.LoggedOut");

export const codecForBackendState = (): Codec<BackendState> =>
  buildCodecForUnion<BackendState>()
    .discriminateOn("status")
    .alternative("loggedIn", codecForBackendStateLoggedIn())
    .alternative("loggedOut", codecForBackendStateLoggedOut())
    .alternative("expired", codecForBackendStateExpired())
    .build("BackendState");

export const defaultState: BackendState = {
  status: "loggedOut",
};

export interface BackendStateHandler {
  state: BackendState;
  logOut(): void;
  expired(): void;
  logIn(info: { username: string, token: AccessToken }): void;
}

const BACKEND_STATE_KEY = buildStorageKey(
  "bank-state",
  codecForBackendState(),
);

/**
 * Return getters and setters for
 * login credentials and backend's
 * base URL.
 */
export function useBackendState(): BackendStateHandler {
  const { value: state, update } = useLocalStorage(
    BACKEND_STATE_KEY,
    defaultState,
  );
  const mutateAll = useMatchMutate();

  return {
    state,
    logOut() {
      update(defaultState);
    },
    expired() {
      if (state.status === "loggedOut") return;
      const nextState: BackendState = {
        status: "expired",
        username: state.username,
        isUserAdministrator: state.username === "admin",
      };
      update(nextState);
    },
    logIn(info) {
      //admin is defined by the username
      const nextState: BackendState = {
        status: "loggedIn",
        ...info,
        isUserAdministrator: info.username === "admin",
      };
      update(nextState);
      mutateAll(/.*/)
    },
  };
}

export function useMatchMutate(): (
  re: RegExp,
  value?: unknown,
) => Promise<any> {
  const { cache, mutate } = useSWRConfig();

  if (!(cache instanceof Map)) {
    throw new Error(
      "matchMutate requires the cache provider to be a Map instance",
    );
  }

  return function matchRegexMutate(re: RegExp, value?: unknown) {
    const allKeys = Array.from(cache.keys());
    const keys = allKeys.filter((key) => re.test(key));
    const mutations = keys.map((key) => {
      return mutate(key, value, true);
    });
    return Promise.all(mutations);
  };
}