import { Injectable, Logger } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import * as nodemailer from 'nodemailer';

@Injectable()
export class MailService {
  private readonly logger = new Logger(MailService.name);
  private transporter: nodemailer.Transporter;

  constructor(private readonly configService: ConfigService) {
    this.transporter = nodemailer.createTransport({
      host: this.configService.get<string>('SMTP_HOST', ''),
      port: this.configService.get<number>('SMTP_PORT', 587),
      secure: this.configService.get<string>('SMTP_SECURE', 'false') === 'true',
      auth: {
        user: this.configService.get<string>('SMTP_USER', ''),
        pass: this.configService.get<string>('SMTP_PASS', ''),
      },
    });
  }

  async sendMail(options: {
    to: string;
    subject: string;
    body: string;
    html?: string;
    attachments?: { filename: string; content: Buffer }[];
  }): Promise<void> {
    const from = this.configService.get<string>('SMTP_FROM', 'paperless@localhost');

    await this.transporter.sendMail({
      from,
      to: options.to,
      subject: options.subject,
      text: options.body,
      html: options.html,
      attachments: options.attachments?.map(a => ({
        filename: a.filename,
        content: a.content,
      })),
    });

    this.logger.log(`Mail gesendet an ${options.to}: "${options.subject}"`);
  }
}