import * as os from 'os';
import * as path from 'path';
import * as fs from 'fs';
import * as https from 'https';
import { getLogger } from "../shared/config";
import formData from 'form-data';
import Mailgun from 'mailgun.js';
const { convert } = require('html-to-text');

const mailgun = new Mailgun(formData);
const logger = getLogger();

export async function sendEmailWithAttachmentUtil(
  toAddress: string, 
  subject: string, 
  message: string, 
  fileUrl: string, 
  fileName?: string
): Promise<any> {
  try {
    const tempFilePath = path.join(os.tmpdir(), fileName || 'attachment.pdf');
    await new Promise<void>((resolve, reject) => {
      const file = fs.createWriteStream(tempFilePath);
      https.get(fileUrl, (res) => {
        res.pipe(file);
        file.on('finish', () => {
          file.close();
          resolve();
        });
      }).on('error', (err) => {
        fs.unlink(tempFilePath, () => {});
        reject(err);
      });
    });

    try {
      const client = mailgun.client({ username: 'api', key: process.env.MAILGUN_API_KEY! });
      const options = {
        wordwrap: 130,
      };
      const textMessage = convert(message, options);
      const fileBuffer = fs.readFileSync(tempFilePath);
      const attachmentFilename = fileName || path.basename(fileUrl.split('?')[0]);
      
      const data = {
        from: process.env.MAILGUN_FROM_ADDRESS,
        to: toAddress,
        subject: subject,
        text: textMessage,
        html: message,
        attachment: {
          data: fileBuffer,
          filename: attachmentFilename,
          contentType: 'application/pdf',
        }
      };
      
      const result = await client.messages.create(process.env.MAILGUN_SERVER!, data);
      fs.unlinkSync(tempFilePath);
      logger.info('Email with attachment from URL sent successfully');
      return { success: true, result };
    } catch (e) {
      logger.error(`Error while sending E-mail. Error: ${e}`);
      throw e;
    }
  } catch (error) {
    logger.error('Error sending email with attachment from URL:', error);
    throw error;
  }
}