(Feat): Initial Commit

internal/mailer/mailer.go

@@ -0,0 +1,162 @@
+package mailer
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"html/template"
+	"os"
+	"path/filepath"
+
+	"allaboutapps.dev/aw/go-starter/internal/config"
+	"allaboutapps.dev/aw/go-starter/internal/data/dto"
+	"allaboutapps.dev/aw/go-starter/internal/mailer/transport"
+	"allaboutapps.dev/aw/go-starter/internal/util"
+	"github.com/jordan-wright/email"
+	"github.com/rs/zerolog/log"
+)
+
+var (
+	ErrEmailTemplateNotFound         = errors.New("email template not found")
+	emailTemplatePasswordReset       = "password_reset"       // /app/templates/email/password_reset/**.
+	emailTemplateAccountConfirmation = "account_confirmation" // /app/templates/email/account_confirmation/**
+)
+
+type Mailer struct {
+	Config    config.Mailer
+	Transport transport.MailTransporter
+	Templates map[string]*template.Template
+}
+
+func New(config config.Mailer, transport transport.MailTransporter) *Mailer {
+	return &Mailer{
+		Config:    config,
+		Transport: transport,
+		Templates: map[string]*template.Template{},
+	}
+}
+
+func NewWithConfig(cfg config.Mailer, smtpConfig transport.SMTPMailTransportConfig) (*Mailer, error) {
+	var mailer *Mailer
+
+	switch config.MailerTransporter(cfg.Transporter) {
+	case config.MailerTransporterMock:
+		log.Warn().Msg("Initializing mock mailer")
+		mailer = New(cfg, transport.NewMock())
+	case config.MailerTransporterSMTP:
+		mailer = New(cfg, transport.NewSMTP(smtpConfig))
+	default:
+		return nil, fmt.Errorf("unsupported mail transporter: %s", cfg.Transporter)
+	}
+
+	if err := mailer.ParseTemplates(); err != nil {
+		return nil, fmt.Errorf("failed to parse mailer templates: %w", err)
+	}
+
+	return mailer, nil
+}
+
+func (m *Mailer) ParseTemplates() error {
+	files, err := os.ReadDir(m.Config.WebTemplatesEmailBaseDirAbs)
+	if err != nil {
+		log.Error().Str("dir", m.Config.WebTemplatesEmailBaseDirAbs).Err(err).Msg("Failed to read email templates directory while parsing templates")
+		return fmt.Errorf("failed to read email templates directory while parsing templates: %w", err)
+	}
+
+	for _, file := range files {
+		if !file.IsDir() {
+			continue
+		}
+
+		tmpl, err := template.ParseGlob(filepath.Join(m.Config.WebTemplatesEmailBaseDirAbs, file.Name(), "**"))
+		if err != nil {
+			log.Error().Str("template", file.Name()).Err(err).Msg("Failed to parse email template files as glob")
+			return fmt.Errorf("failed to parse email template files as glob: %w", err)
+		}
+
+		m.Templates[file.Name()] = tmpl
+	}
+
+	return nil
+}
+
+func (m *Mailer) SendPasswordReset(ctx context.Context, to string, passwordResetLink string) error {
+	log := util.LogFromContext(ctx).With().Str("component", "mailer").Str("email_template", emailTemplatePasswordReset).Logger()
+
+	tmpl, ok := m.Templates[emailTemplatePasswordReset]
+	if !ok {
+		log.Error().Msg("Password reset email template not found")
+		return ErrEmailTemplateNotFound
+	}
+
+	data := map[string]interface{}{
+		"passwordResetLink": passwordResetLink,
+	}
+
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, data); err != nil {
+		log.Error().Err(err).Msg("Failed to execute password reset email template")
+		return fmt.Errorf("failed to execute password reset email template: %w", err)
+	}
+
+	mail := email.NewEmail()
+
+	mail.From = m.Config.DefaultSender
+	mail.To = []string{to}
+	mail.Subject = "Password reset"
+	mail.HTML = buf.Bytes()
+
+	if !m.Config.Send {
+		log.Warn().Str("to", to).Str("passwordResetLink", passwordResetLink).Msg("Sending has been disabled in mailer config, skipping password reset email")
+		return nil
+	}
+
+	if err := m.Transport.Send(mail); err != nil {
+		log.Debug().Err(err).Msg("Failed to send password reset email")
+		return fmt.Errorf("failed to send password reset email: %w", err)
+	}
+
+	log.Debug().Msg("Successfully sent password reset email")
+
+	return nil
+}
+
+func (m *Mailer) SendAccountConfirmation(ctx context.Context, to string, payload dto.ConfirmatioNotificationPayload) error {
+	log := util.LogFromContext(ctx)
+
+	tmpl, ok := m.Templates[emailTemplateAccountConfirmation]
+	if !ok {
+		log.Error().Msg("Account confirmation email template not found")
+		return ErrEmailTemplateNotFound
+	}
+
+	data := map[string]interface{}{
+		"confirmationLink": payload.ConfirmationLink,
+	}
+
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, data); err != nil {
+		log.Error().Err(err).Msg("Failed to execute account confirmation email template")
+		return fmt.Errorf("failed to execute account confirmation email template: %w", err)
+	}
+
+	mail := email.NewEmail()
+
+	mail.From = m.Config.DefaultSender
+	mail.To = []string{to}
+	mail.Subject = "Account confirmation"
+	mail.HTML = buf.Bytes()
+
+	if !m.Config.Send {
+		log.Warn().Str("to", to).Msg("Sending has been disabled in mailer config, skipping account confirmation email")
+		return nil
+	}
+
+	if err := m.Transport.Send(mail); err != nil {
+		log.Debug().Err(err).Msg("Failed to send account confirmation email")
+		return fmt.Errorf("failed to send account confirmation email: %w", err)
+	}
+
+	return nil
+}