import { Type } from '@nestjs/common';
import { ContextId, ModuleRef } from '@nestjs/core';
import { getConnectionToken } from '@nestjs/typeorm';
import { Connection } from 'typeorm';

/**
 * @description
 * The Injector wraps the underlying Nestjs `ModuleRef`, allowing injection of providers
 * known to the application's dependency injection container. This is intended to enable the injection
 * of services into objects which exist outside of the Nestjs module system, e.g. the various
 * Strategies which can be supplied in the VendureConfig.
 *
 * @docsCategory common
 */
export class Injector {
    constructor(private moduleRef: ModuleRef) {}

    /**
     * @description
     * Retrieve an instance of the given type from the app's dependency injection container.
     * Wraps the Nestjs `ModuleRef.get()` method.
     */
    get<T, R = T>(typeOrToken: Type<T> | string | symbol): R {
        return this.moduleRef.get(typeOrToken, { strict: false });
    }

    /**
     * @description
     * Retrieve an instance of the given scoped provider (transient or request-scoped) from the
     * app's dependency injection container.
     * Wraps the Nestjs `ModuleRef.resolve()` method.
     */
    resolve<T, R = T>(typeOrToken: Type<T> | string | symbol, contextId?: ContextId): Promise<R> {
        return this.moduleRef.resolve(typeOrToken, contextId, { strict: false });
    }
}