yumechi-no-kuni/src/api.ts
2021-06-26 02:00:22 +09:00

96 lines
3 KiB
TypeScript

import { Endpoints } from './api.types';
const MK_API_ERROR = Symbol();
export type APIError = {
id: string;
code: string;
message: string;
kind: 'client' | 'server';
info: Record<string, any>;
};
export function isAPIError(reason: any): reason is APIError {
return reason[MK_API_ERROR] === true;
}
export type FetchLike = (input: string, init?: {
method?: string;
body?: string;
credentials?: RequestCredentials;
cache?: RequestCache;
}) => Promise<{
status: number;
json(): Promise<any>;
}>;
type IsNeverType<T> = [T] extends [never] ? true : false;
type StrictExtract<Union, Cond> = Cond extends Union ? Union : never;
type IsCaseMatched<E extends keyof Endpoints, P extends Endpoints[E]['req'], C extends number> =
IsNeverType<StrictExtract<Endpoints[E]['res']['$switch']['$cases'][C], [P, any]>> extends false ? true : false;
type GetCaseResult<E extends keyof Endpoints, P extends Endpoints[E]['req'], C extends number> =
StrictExtract<Endpoints[E]['res']['$switch']['$cases'][C], [P, any]>[1];
export class APIClient {
public origin: string;
public credential: string | null | undefined;
public fetch: FetchLike;
constructor(opts: {
origin: APIClient['origin'];
credential?: APIClient['credential'];
fetch?: APIClient['fetch'] | null | undefined;
}) {
this.origin = opts.origin;
this.credential = opts.credential;
this.fetch = opts.fetch || fetch;
}
public request<E extends keyof Endpoints, P extends Endpoints[E]['req']>(
endpoint: E, params: P = {} as P, credential?: string | null | undefined,
): Promise<Endpoints[E]['res'] extends { $switch: { $cases: [any, any][]; $default: any; }; }
?
IsCaseMatched<E, P, 0> extends true ? GetCaseResult<E, P, 0> :
IsCaseMatched<E, P, 1> extends true ? GetCaseResult<E, P, 1> :
IsCaseMatched<E, P, 2> extends true ? GetCaseResult<E, P, 2> :
IsCaseMatched<E, P, 3> extends true ? GetCaseResult<E, P, 3> :
IsCaseMatched<E, P, 4> extends true ? GetCaseResult<E, P, 4> :
IsCaseMatched<E, P, 5> extends true ? GetCaseResult<E, P, 5> :
IsCaseMatched<E, P, 6> extends true ? GetCaseResult<E, P, 6> :
IsCaseMatched<E, P, 7> extends true ? GetCaseResult<E, P, 7> :
IsCaseMatched<E, P, 8> extends true ? GetCaseResult<E, P, 8> :
IsCaseMatched<E, P, 9> extends true ? GetCaseResult<E, P, 9> :
Endpoints[E]['res']['$switch']['$default']
: Endpoints[E]['res']>
{
const promise = new Promise((resolve, reject) => {
this.fetch(`${this.origin}/api/${endpoint}`, {
method: 'POST',
body: JSON.stringify({
...params,
i: credential !== undefined ? credential : this.credential
}),
credentials: 'omit',
cache: 'no-cache'
}).then(async (res) => {
const body = res.status === 204 ? null : await res.json();
if (res.status === 200) {
resolve(body);
} else if (res.status === 204) {
resolve(null);
} else {
reject({
[MK_API_ERROR]: true,
...body.error
});
}
}).catch(reject);
});
return promise as any;
}
}