udemy-go-microservices/mail-service/cmd/api/handlers.go

package main

import (
	"errors"
	"fmt"
	"log"
	"net/http"
	"time"

	"github.com/tsawler/toolbox"
	mail "github.com/xhit/go-simple-mail/v2"
)

type MailData struct {
	From    string `json:"from"`
	To      string `json:"to"`
	Subject string `json:"subject"`
	Content string `json:"content"`
}

func (app *Config) SendMail(w http.ResponseWriter, r *http.Request) {
	var mailData MailData
	err := app.Tools.ReadJSON(w, r, &mailData)
	if err != nil {
		log.Println(err)
		app.Tools.ErrorJSON(w, err)
		return
	}
	log.Println("Sending mail")

	if mailData.From == "" || mailData.To == "" ||
		(mailData.Subject == "" && mailData.Content == "") {
		log.Println("Invalid mail")
		app.Tools.ErrorJSON(w, errors.New("invalid mail"), http.StatusBadRequest)
		return
	}

	err = app.SendMsg(mailData)
	if err != nil {
		log.Println(err)
		app.Tools.ErrorJSON(w, err)
		return
	}

	var payload toolbox.JSONResponse
	payload.Error = false
	payload.Message = fmt.Sprintf("mail sent to %s", mailData.To)

	app.Tools.WriteJSON(w, http.StatusAccepted, payload)
}

func (app *Config) SendMsg(m MailData) error {
	server := mail.NewSMTPClient()
	server.Host = app.Host
	server.Port = app.Port

	server.KeepAlive = false
	server.ConnectTimeout = 10 * time.Second
	server.SendTimeout = 10 * time.Second

	smtpClient, err := server.Connect()
	if err != nil {
		log.Println(err)
		return err
	}

	// Maybe add a template

	email := mail.NewMSG()
	email.SetFrom(m.From).
		AddTo(m.To).
		SetSubject(m.Subject).
		SetBody(mail.TextHTML, m.Content)

	err = email.Send(smtpClient)
	if err != nil {
		log.Println(err)
		return err
	}

	log.Printf("Email sent to %s", m.To)

	return nil
}