typescript source code of strategy.registry

import {Oauth2GrantStrategyInterface} from "./oauth2-grant-strategy.interface";
import {OAuth2Request, OAuth2Response} from "../../ui/dto";
import {HttpException, Injectable, Type} from "@nestjs/common";
import {ModuleRef} from "@nestjs/core";
import {OAUTH2_STRATEGY_METADATA} from "./strategy.explorer";
import {ClientEntity} from "../client.entity";

export type Oauth2GrantStrategyType = Type<Oauth2GrantStrategyInterface>;

/**
 * This is the main class used to execute strategies
 */
@Injectable()
export class Oauth2GrantStrategyRegistry {
    /**
     * Store all available granted strategy
     */
    private registry: { [s: string]: Oauth2GrantStrategyInterface } = {};

    constructor(
        private readonly moduleRef: ModuleRef,
    ) {}

    /**
     * Register a single strategy
     *
     * @param strategy
     */
    protected registerStrategy(strategy: Oauth2GrantStrategyType): void {
        const instance = this.moduleRef.get(strategy, {strict: false});
        if (!instance) {
            return;
        }

        const strategyName = this.reflectStrategyName(strategy);
        this.registry[strategyName] = instance as Oauth2GrantStrategyInterface;
    }

    /**
     * Register all strategies with the decorator
     *
     * @param strategies
     */
    register(strategies: Oauth2GrantStrategyType[] = []) {
        strategies.forEach(strategy => this.registerStrategy(strategy));
    }

    /**
     * Validate the client associated to the given request
     * 
     * @param request
     * @param client
     */
    async validate(request: OAuth2Request, client: ClientEntity): Promise<boolean> {
        if (!(request.grantType in this.registry)) {
            throw new HttpException(`Cannot find the a strategy for the grant type "${request.grantType}"`, 400);
        }

        return await this.registry[request.grantType].validate(request, client);
    }

    /**
     * Get the response
     *
     * @param request
     * @param client
     */
    async getOauth2Response(request: OAuth2Request, client: ClientEntity): Promise<OAuth2Response> {
        if (!(request.grantType in this.registry)) {
            throw new HttpException(`Cannot find the a strategy for the grant type "${request.grantType}"`, 400);
        }

        return await this.registry[request.grantType].getOauth2Response(request, client);
    }

    private reflectStrategyName(strategy: Oauth2GrantStrategyType): string {
        return Reflect.getMetadata(OAUTH2_STRATEGY_METADATA, strategy);
    }
}