package common_email

import (
  "github.com/wneessen/go-mail"
  "encoding/json"
  "context"
  "github.com/redis/go-redis/v9"
)

func NewSender(ctx context.Context, config Config) (Sender){
  client := redis.NewClient(&redis.Options{
    Addr: config.RedisHostPort,
    Password: config.RedisPassword,
    DB: config.RedisDB,
  })

  return Sender{client, ctx}
}

func NewRouter(ctx context.Context, config Config) (Router, error) {
  var router Router
  var err error

  router.ctx = ctx

  router.redis_client = redis.NewClient(&redis.Options{
    Addr: config.RedisHostPort,
    Password: config.RedisPassword,
    DB: config.RedisDB,
  })

  router.smtp_client, err = mail.NewClient(config.SMTPHost,
    mail.WithPort(config.SMTPPort),
    mail.WithTLSPolicy(mail.NoTLS))

  return router, err
}

func (router *Router) Close() {
  router.redis_client.Close()
  router.smtp_client.Close()
}

func (sender *Sender) Close() {
  sender.redis_client.Close()
}

func (router *Router) DeliverEmail(msg EmailMessage) error {
  email_msg := mail.NewMsg()
  err := email_msg.From(msg.From)
  if err != nil { return err }

  err = email_msg.To(msg.To)
  if err != nil { return err }

  email_msg.Subject(msg.Subject)
  email_msg.SetBodyString(mail.TypeTextPlain, msg.Text)
  email_msg.SetBodyString(mail.TypeTextHTML, msg.HTML)

  if err != nil { return err }

  err = router.smtp_client.DialAndSendWithContext(router.ctx, email_msg)
  if err != nil { return err }

  return nil
}

func (router *Router) ReceiveEmail() (EmailMessage, error) {
  var msg EmailMessage

  result, err := router.redis_client.BRPop(router.ctx, 0, "queue").Result()
  if err != nil { return msg, err }

  // NOTE: 0=queue name, 1=message
  err = json.Unmarshal([]byte(result[1]), &msg)
  if err != nil { return msg, err }

  return msg, nil
}

func (router *Router) HandleEmailRequest() error {
  msg, err := router.ReceiveEmail()
  if err != nil { return err }

  err = router.DeliverEmail(msg)
  if err != nil { return err }

  return nil
}

func (sender *Sender) QueueEmail(msg EmailMessage) error {
  msg_json, err := json.Marshal(msg)
  if err != nil { return err }

  _, err = sender.redis_client.LPush(sender.ctx, "queue", string(msg_json)).Result()
  if err != nil { return err }

  return nil
}