import nodemailer from 'nodemailer';
import moment from 'moment';
import type { RowDataPacket } from 'mysql2';
import pool from './mysql';
import { checkAblauf } from './checkAblauf';

// SMTP-Konfiguration via Umgebungsvariablen (Passwort niemals hart codieren!)
const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST || 'smtp.1und1.de',
  port: parseInt(process.env.SMTP_PORT || '587', 10),
  secure: false,
  auth: {
    user: process.env.SMTP_USER || '',
    pass: process.env.SMTP_PASS || '',
  },
});

export async function doCheckAndMail(): Promise<string> {
  const [rows] = await pool.query<RowDataPacket[]>(
    'SELECT tab, pday, cnt, at FROM tabletten'
  );

  let body = '';

  for (const item of rows) {
    if (item.pday !== 0) {
      const updates = checkAblauf({ cnt: item.cnt, pday: item.pday, at: item.at });
      await pool.execute(
        'UPDATE tabletten SET akt = ?, until = ?, warn = ? WHERE tab = ?',
        [updates.akt, moment(updates.until).format('YYYY-MM-DD'), updates.warn ? 1 : 0, item.tab]
      );
      if (updates.warn) {
        const name = item.tab.split(' ')[0];
        body += `"${name}" wird am ${moment(updates.until).format('YYYY-MM-DD')} (in ${updates.rtage} Tagen) zu Ende sein\n`;
      }
    }
  }

  if (body) {
    await transporter.sendMail({
      from: `"Tabletten" <${process.env.SMTP_USER}>`,
      to: process.env.MAIL_TO || '',
      subject: 'Tabletten gehen zu Ende',
      text: body,
    });
  }

  return body || 'Kein Warn-Eintrag.';
}