import { ExecutionContext, Injectable, Logger } from '@nestjs/common';

@Injectable()
export default class AmqpResolver implements I18nResolver {
  private logger = new Logger('I18nService');

  constructor(
    @I18nResolverOptions()
    private keys: string[] = ['x-lang'],
  ) {}

  resolve(context: ExecutionContext) {
    const ctx = context.switchToRpc().getContext();
    const message = ctx.getMessage();

    let lang: string;

    if (message) {
      for (const key of this.keys) {
        if (message?.properties?.headers[key] !== undefined) {
          this.logger.log(
            `Detected header '${key}' with value: '${message.properties.headers[key]}'`,
          );
          lang = message.properties.headers[key];
          break;
        }
      }
    }

    if (!lang) {
      this.logger.warn(
        `No language detected. None of the following headers were found in message: ${this.keys.join(', ')}`,
      );
    }

    return lang;
  }
}

import { Module } from '@nestjs/common';
import config from './config';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { EmailController } from './controller/email.controller';
import { MailerModule } from '@nestjs-modules/mailer';
import { HandlebarsAdapter } from '@nestjs-modules/mailer/dist/adapters/handlebars.adapter';
import { join } from 'path';
import { EmailService } from './services/email.service';
import { I18nModule, I18nService } from 'nestjs-i18n';
import { AmqpResolver } from './common/resolver';

@Module({
  imports: [
    ConfigModule.forRoot({
      load: config,
      isGlobal: true,
      cache: true,
      envFilePath: ['.env', '.env.local'],
      expandVariables: true,
    }),
    I18nModule.forRootAsync({
      useFactory: () => ({
        disableMiddleware: false,
        fallbackLanguage: 'en',
        viewEngine: 'hbs',
        loaderOptions: {
          path: join(__dirname, '/assets/i18n/'),
        },
      }),
      resolvers: [new AmqpResolver()],
    }),
    MailerModule.forRootAsync({
      inject: [ConfigService, I18nService],
      useFactory: (configs: ConfigService, i18n: I18nService) => {
        console.log(i18n.getTranslations());
        return {
          transport: {
            host: configs.get('smtp.host'),
            port: configs.get('smtp.port'),
            secure: configs.get('smtp.InsecureSkipVerify'),
            auth: {
              user: configs.get('smtp.user'),
              pass: configs.get('smtp.password'),
            },
          },
          template: {
            dir: join(__dirname, 'assets/template'),
            adapter: new HandlebarsAdapter({ t: i18n.hbsHelper }),
            options: {
              strict: true,
            },
          },
        };
      },
    }),
  ],
  controllers: [EmailController],
  providers: [EmailService],
})
export class AppModule {}