package mailer

import (
	"errors"
	"net/mail"

	"gitserver.in/patialtech/rano/config"
)

type (
	transporter interface {
		send(*message) error
	}

	Recipients struct {
		To  []mail.Address `json:"to"`
		Cc  []mail.Address `json:"cc"`
		Bcc []mail.Address `json:"bcc"`
	}

	message struct {
		From       string        `json:"from" validate:"required"`
		Recipients Recipients    `json:"recipients" validate:"required"`
		Subject    string        `json:"subject" validate:"required"`
		HtmlBody   string        `json:"htmlBody" validate:"required"`
		ReplyTo    *mail.Address `json:"replyTo"`
	}

	Template interface {
		Subject() string
		HtmlBody() (string, error)
	}
)

func Send(to []mail.Address, tpl Template) error {
	return send(Recipients{To: to}, tpl)
}

func SendCC(subject string, to, cc []mail.Address, tpl Template) error {
	return send(Recipients{To: to, Cc: cc}, tpl)
}

func send(recipients Recipients, tpl Template) error {
	if tpl == nil {
		return errors.New("mailer: email template is nil")
	}

	if len(recipients.To) == 0 {
		return errors.New("mailer: no recipient found")
	}

	// TODO remove recepient with bounce hiostory

	body, err := tpl.HtmlBody()
	if err != nil {
		return err
	}
	// get ENV based transporter and send mail
	return getTransporter().send(&message{
		From:       config.Read().MailerFrom,
		Recipients: recipients,
		Subject:    tpl.Subject(),
		HtmlBody:   body,
	})
}

func getTransporter() transporter {
	switch config.AppEnv {
	default:
		return transportDev{}
	}
}