import { DynamicModule, Module, Provider } from '@nestjs/common';
import { S3Client } from '@aws-sdk/client-s3';
import { MediaManagerService } from './media-manager.service';
import { LocalStorageAdapter } from './adapters/local.adapter';
import { S3StorageAdapter } from './adapters/s3.adapter';

export interface MediaManagerAwsOptions {
  region?: string;
  endpoint?: string;
  accessKeyId?: string;
  secretAccessKey?: string;
  bucket?: string;
}

export interface MediaManagerModuleOptions {
  localRoot?: string;
  aws?: MediaManagerAwsOptions;
}

export interface MediaManagerModuleAsyncOptions {
  imports?: any[];
  inject?: any[];
  useFactory: (...args: any[]) => Promise<MediaManagerModuleOptions> | MediaManagerModuleOptions;
}

const S3_CLIENT = 'MEDIA_MANAGER_S3_CLIENT';
const MEDIA_MANAGER_OPTIONS = 'MEDIA_MANAGER_OPTIONS';

@Module({})
export class MediaManagerModule {
  static register(options?: MediaManagerModuleOptions): DynamicModule {
    return this.registerAsync({
      useFactory: () => options ?? {},
    });
  }

  static registerAsync(
    asyncOptions: MediaManagerModuleAsyncOptions,
  ): DynamicModule {
    const providers: Provider[] = this.createProviders();
    const optionProvider: Provider = {
      provide: MEDIA_MANAGER_OPTIONS,
      useFactory: asyncOptions.useFactory,
      inject: asyncOptions.inject || [],
    };

    return {
      module: MediaManagerModule,
      imports: asyncOptions.imports || [],
      providers: [optionProvider, ...providers],
      exports: [MediaManagerService],
    };
  }

  private static createProviders(): Provider[] {
    const localStorageProvider: Provider = {
      provide: LocalStorageAdapter,
      useFactory: (options: MediaManagerModuleOptions) =>
        new LocalStorageAdapter(options.localRoot),
      inject: [MEDIA_MANAGER_OPTIONS],
    };

    const s3ClientProvider: Provider = {
      provide: S3_CLIENT,
      useFactory: (options: MediaManagerModuleOptions) =>
        new S3Client({
          region: options.aws?.region,
          endpoint: options.aws?.endpoint,
          credentials:
            options.aws?.accessKeyId && options.aws?.secretAccessKey
              ? {
                  accessKeyId: options.aws.accessKeyId,
                  secretAccessKey: options.aws.secretAccessKey,
                }
              : undefined,
        }),
      inject: [MEDIA_MANAGER_OPTIONS],
    };

    const s3StorageAdapterProvider: Provider = {
      provide: S3StorageAdapter,
      useFactory: (client: S3Client, options: MediaManagerModuleOptions) =>
        new S3StorageAdapter(client, options.aws?.bucket ?? ''),
      inject: [S3_CLIENT, MEDIA_MANAGER_OPTIONS],
    };

    const serviceProvider: Provider = {
      provide: MediaManagerService,
      useFactory: (
        localAdapter: LocalStorageAdapter,
        s3Adapter: S3StorageAdapter,
      ) => new MediaManagerService(localAdapter, s3Adapter),
      inject: [LocalStorageAdapter, S3StorageAdapter],
    };

    return [
      localStorageProvider,
      s3ClientProvider,
      s3StorageAdapterProvider,
      serviceProvider,
    ];
  }
}