import { DynamicModule, ForwardReference, Module, Provider, Type } from "@nestjs/common";
import { RedisClientOptions, RedisModules, RedisScripts } from "redis";
import { REDIS_CONFIG } from "./constants";
import { RedisModuleInitializationException } from "./exceptions";
import { RedisService } from "./redis.service";

export type RedisModuleOptions = RedisClientOptions<RedisModules, RedisScripts>;
export interface AsyncModuleOptions<T> {
	imports?: (DynamicModule | Type<any> | Promise<DynamicModule> | ForwardReference)[],
	useFactory?: (...args: any[]) => Promise<T> | T;
	inject?: any[];
}

@Module({})
export class RedisModule {

	static register(options: RedisModuleOptions): DynamicModule {
		return {
			module: RedisModule,
			providers: [{ provide: REDIS_CONFIG, useValue: options }, RedisService],
			exports: [RedisService]
		}
	}

	static registerAsync(options: AsyncModuleOptions<RedisModuleOptions>): DynamicModule {
		return {
			module: RedisModule,
			imports: [...(options.imports || [])],
			providers: [RedisModule.createAsyncRedisConfigProvider(options), RedisService],
			exports: [RedisService],
		}
	}

	private static createAsyncRedisConfigProvider(options: AsyncModuleOptions<RedisModuleOptions>): Provider {
		if (options.useFactory) {
			return {
				provide: REDIS_CONFIG,
				useFactory: options.useFactory,
				inject: [...(options.inject || [])]
			}
		}

		throw new RedisModuleInitializationException('Redis Module asynchronous registrations MUST `useFactory`');
	}
}