newsbox/mill/mill.go

package mill

import (
	"database/sql"
	"encoding/json"
	"log"
	"newsbox/internal"
	"newsbox/mailers"
	"newsbox/models"
	"time"

	"github.com/btubbs/pgq"
)

type Handler interface {
	Perform(payload []byte) (err error)
}

type IncomingEmailHandler struct {
	Handler
	Worker *pgq.Worker
	Db     *sql.DB
}

type OutgoingEmailHandler struct {
	Handler
	Worker *pgq.Worker
	Db     *sql.DB
}

type WelcomeEmailHandler struct {
	Handler
	Worker *pgq.Worker
	Db     *sql.DB
}

type EmailChangedEmailHandler struct {
	Handler
	Worker *pgq.Worker
	Db     *sql.DB
}

type WelcomeEmailJob struct {
	Recipient       string
	VerificationURL string
}

type EmailAddressChangeEmailJob struct {
	Recipient       string
	VerificationURL string
}

// Process processes incoming models.Message payloads
func (h *IncomingEmailHandler) Process(payload []byte) (err error) {
	var msg models.Message
	err = json.Unmarshal(payload, &msg)
	if err != nil {
		return
	}
	var owner models.User
	err = models.DB.Eager().Find(&owner, msg.OwnerID)
	if err != nil {
		return
	}

	// Re-address the email to the user's email address
	msg.To = owner.Email.Interface().(string)

	// Determine time to deliver
	tzOffset := owner.Preferences.TimeZoneUtcOffset

	t := internal.TimeInZone(tzOffset)
	et := time.Date(t.Year(), t.Month(), t.Day(), owner.Preferences.EmailHourOfDay, 0, 0, 0, t.Location())
	diff := et.Sub(t)

	// The message should be delivered later today
	if diff > 0 {
		et = t.Add(diff)
	} else { // The message should be delivered tomorrow
		et = time.Date(t.Year(), t.Month(), t.Day()+1, owner.Preferences.EmailHourOfDay, 0, 0, 0, t.Location())
	}

	log.Println("Queueing for:", et)
	log.Println("Assumed location:", t.Location())
	job, _ := json.MarshalIndent(&msg, "", "\t")
	_, err = h.Worker.EnqueueJob("outgoing_email", job, pgq.After(et))

	return
}

// Process processes outgoing models.Message payloads
func (w *OutgoingEmailHandler) Process(payload []byte) (err error) {
	var msg models.Message
	err = json.Unmarshal(payload, &msg)
	if err != nil {
		return
	}
	var owner models.User
	err = models.DB.Find(&owner, msg.OwnerID)
	if err != nil {
		return
	}

	err = mailers.ForwardMessage(owner.Email.Interface().(string), &msg)

	return
}

// Process processes new welcome email jobs
func (h *WelcomeEmailHandler) Process(payload []byte) (err error) {
	var job WelcomeEmailJob
	err = json.Unmarshal(payload, &job)
	if err != nil {
		return
	}

	err = mailers.SendWelcomeEmail(job.Recipient, job.VerificationURL)
	return
}

// Process processes changes to user account email addresses
func (h *EmailChangedEmailHandler) Process(payload []byte) (err error) {
	var job EmailAddressChangeEmailJob
	err = json.Unmarshal(payload, &job)
	if err != nil {
		return
	}

	err = mailers.SendEmailAddressChangedEmail(job.Recipient, job.VerificationURL)
	return
}