/*
 * Hexacode Mailer
 * Package: gitlab.hexacode.org/go-libs/mailer
 * Maintainer: Azzis Arswendo <azzis@hexacode.org>
 *
 * Copyright (C) 2023 Hexacode Teknologi Indonesia
 * All Rights Reserved
 */

// Example:
//
// ```go
//
// package main
//
// import (
//
//	"gitlab.hexacode.org/go-libs/hctypes"
//	"gitlab.hexacode.org/go-libs/mailer"
//
// )
//
//	func main() {
//	  // Create a new template
//	  // Please see https://github.com/noirbizarre/gonja for more details template
//	  tmpl, err := mailer.NewTemplate("Hello {{ name }}!")
//	  if err != nil {
//	    panic(err)
//	  }
//
//	  // Create a new sender
//	  sender := mailer.NewSender("Example Sender", "example-sender@gmail.com", "password", "smtp.gmail.com", 587, tmpl)
//
//	  // Send an email
//	  err = sender.SendEmail("example-recipient@gmail.com", "Example Subject", hctypes.Dict{"name": "John Doe"})
//	  if err != nil {
//	    panic(err)
//	  }
//	}
//
// ```
package mailer

import (
	"fmt"

	"github.com/go-mail/mail"
	"gitlab.hexacode.org/go-libs/hctypes"
)

// Sender represents a mail sender
type Sender struct {
	sender_name    string    // The name of the sender
	sender_address string    // The email address of the sender
	password       string    // The password of the sender
	smtp_host      string    // The smtp host (eg: smtp.gmail.com)
	smtp_port      int       // The smtp port (eg: 587)
	Template       *Template // The template *Template
}

// NewSender creates a new Sender
//
// sender_name: The name of the sender
// sender_address: The email address of the sender
// password: The password of the sender
// smtp_host: The smtp host (eg: smtp.gmail.com)
// smtp_port: The smtp port (eg: 587)
// template: The template *Template
// Returns: *Sender
func NewSender(sender_name, sender_address, password, smtp_host string, smtp_port int, template *Template) *Sender {
	return &Sender{
		sender_name:    sender_name,
		sender_address: sender_address,
		password:       password,
		smtp_host:      smtp_host,
		smtp_port:      smtp_port,
		Template:       template,
	}
}

// SendEmail sends an email
//
// to: The email address of the recipient
// subject: The subject of the email
// query: The query of the email template
// Returns: error
func (s *Sender) SendEmail(to, subject string, query hctypes.Dict) error {
	from := fmt.Sprintf("%s <%s>", s.sender_name, s.sender_address)

	msg := mail.NewMessage()
	msg.SetHeader("From", from)
	msg.SetHeader("To", to)
	msg.SetHeader("Subject", subject)
	body, err := s.Template.Render(query)
	if err != nil {
		return err
	}

	msg.SetBody("text/html", body)

	dial := mail.NewDialer(s.smtp_host, s.smtp_port, s.sender_address, s.password)
	return dial.DialAndSend(msg)
}