import nodemailer from 'nodemailer';
import handlebars from 'handlebars';
import fs from 'fs';
import path from 'path';
import i18next from 'i18next';

// Nodemailer Transporter 생성
const transporter = nodemailer.createTransport({
  host: process.env.Email_Host,
  port: parseInt(process.env.Email_Port || '465'),
  secure: process.env.Email_Secure === 'true',
  auth: {
    user: process.env.Email_User_Name,
    pass: process.env.Email_Password,
  },
});

// // Handlebars 템플릿 로더 함수
// function loadTemplate(templateName: string, data: Record<string, any>) {
//   const templatePath = path.join(process.cwd(), 'lib', 'mail', 'templates', `${templateName}.hbs`);
//   const source = fs.readFileSync(templatePath, 'utf8');
//   const template = handlebars.compile(source);
//   return template(data);
// }
function applyLayout(layoutName: string, content: string, context: Record<string, any>) {
  const layoutPath = path.join(process.cwd(), 'lib', 'mail', 'layouts', `${layoutName}.hbs`);
  const layoutSource = fs.readFileSync(layoutPath, 'utf8');
  const layoutTemplate = handlebars.compile(layoutSource);
  return layoutTemplate({ ...context, body: content });
}

// Partials 자동 등록
function registerPartials() {
  const partialsDir = path.join(process.cwd(), 'lib', 'mail', 'partials');
  const filenames = fs.readdirSync(partialsDir);

  filenames.forEach((filename) => {
    const name = path.parse(filename).name;
    const filepath = path.join(partialsDir, filename);
    const source = fs.readFileSync(filepath, 'utf8');
    handlebars.registerPartial(name, source); // {{> header }}, {{> footer }}
  });
}


// 템플릿 불러오기 + layout/partials 적용
function loadTemplate(templateName: string, context: Record<string, any>, layout = 'base') {
  registerPartials();

  const templatePath = path.join(process.cwd(), 'lib', 'mail', 'templates', `${templateName}.hbs`);
  const source = fs.readFileSync(templatePath, 'utf8');
  const template = handlebars.compile(source);

  const content = template(context); // 본문 먼저 처리
  return applyLayout(layout, content, context); // base.hbs로 감싸기
}
handlebars.registerHelper('t', function(key: string, options: any) {
    // options.hash에는 Handlebars에서 넘긴 named parameter들(location=location 등)이 들어있음
    return i18next.t(key, options.hash || {});
  });

export { transporter, loadTemplate };