const nodemailer = require('nodemailer');
const schedule = require('node-schedule');
const db2 = require('../config/db2');       // connect to zenclouddb for mail  
const logger = require('../utils/logger'); // 必須引入！

class MailService {
    constructor() {
        this.transporter = nodemailer.createTransport({
            host: "smtp.gmail.com",
            port: 465,
            secure: true, 
            auth: { user: process.env.MAIL_USER, pass: process.env.MAIL_PASS }
        });
    }

    async initAutoMail() {
        // 每 30 秒執行一次
        schedule.scheduleJob('*/30 * * * * *', async () => {
            try {
                // 增加一個簡單的連線檢查，避免資料庫掛掉時噴錯
                const [rows] = await db2.query('SELECT * FROM zen_mail_list WHERE mail_status = 0 LIMIT 10');
                
                if (rows.length > 0) {
                    logger.info(`AutoMail: Processing ${rows.length} messages.`);
                }

                for (let row of rows) {
                    try {
                        await this.transporter.sendMail({
                            from: process.env.MAIL_USER,
                            to: row.recipient,
                            subject: row.mail_subject,
                            // html: row.content  
							// Modify By Michael 20260310
							text: row.content
                        });
                        await db2.query('UPDATE zen_mail_list SET mail_status = 1, create_date = NOW() WHERE id = ?', [row.id]);
                    } catch (mailErr) {
                        logger.error(`Mail ID ${row.id} failed: ${mailErr.message}`);
                        await db2.query('UPDATE zen_mail_list SET mail_status = 9, error_log = ? WHERE id = ?', [mailErr.message, row.id]);
                    }
                }
            } catch (dbErr) {
                // 這裡現在可以正確使用 logger 了
                logger.error(`AutoMail Job DB Failure: ${dbErr.message}`);
            }
        });
    }
}

module.exports = new MailService();