import type { Params, ServiceInterface } from '@feathersjs/feathers';

import type { Application } from '../../declarations';

import { Issuer, generators } from 'openid-client';
import config from 'config';

type AuthOidcResponse = string;
type AuthOidcQuery = any;

export type { AuthOidcResponse as AuthOidc, AuthOidcQuery };

export interface AuthOidcServiceOptions {
    app: Application;
}

export interface AuthOidcParams extends Params<AuthOidcQuery> {
    session?: any;
}

export class AuthOidcService<ServiceParams extends AuthOidcParams = AuthOidcParams>
    implements ServiceInterface<AuthOidcResponse, ServiceParams>
{
    constructor(public options: AuthOidcServiceOptions) {}

    async find(params: ServiceParams): Promise<AuthOidcResponse> {
        const issuer = await Issuer.discover(config.get('oidc.gatewayUri'));
        const client = new issuer.Client({
            client_id: config.get('oidc.clientId'),
            client_secret: config.get('oidc.clientSecret'),
            redirect_uris: [config.get('oidc.redirectUris')],
            response_types: ['code'],
        });
        const codeVerifier = generators.codeVerifier();
        const codeChallenge = generators.codeChallenge(codeVerifier);

        const url = client.authorizationUrl({
            redirect_uri: config.get('clientUrl') + '/auth-oidc/callback',
            scope: 'openid profile offline_access',
            response_type: 'code',
            code_challenge: codeChallenge,
            code_challenge_method: 'S256',
        });

        params.session.codeVerifier = codeVerifier;
        return url;
    }
}

export const getOptions = (app: Application) => {
    return { app };
};