flesh out the email sender interface

internal/email/email.go

@@ -16,5 +16,62 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-// Package email provides a service for interacting with an SMTP server
 package email
+
+import (
+	"fmt"
+	"html/template"
+	"net/smtp"
+	"os"
+	"path/filepath"
+
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+)
+
+// Sender contains functions for sending emails to instance users/new signups.
+type Sender interface {
+	// SendConfirmEmail sends a 'please confirm your email' style email to the given toAddress, with the given data.
+	SendConfirmEmail(toAddress string, data ConfirmData) error
+
+	// SendResetEmail sends a 'reset your password' style email to the given toAddress, with the given data.
+	SendResetEmail(toAddress string, data ResetData) error
+
+	// ExecuteTemplate returns templated HTML using the given templateName and data. Mostly you won't need to call this,
+	// and can just call one of the 'Send' functions instead (which calls this under the hood anyway).
+	ExecuteTemplate(templateName string, data interface{}) (string, error)
+}
+
+func NewSender(cfg *config.Config) (Sender, error) {
+	t, err := loadTemplates(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	auth := smtp.PlainAuth("", cfg.SMTPConfig.Username, cfg.SMTPConfig.Password, cfg.SMTPConfig.Host)
+
+	return &sender{
+		hostAddress: fmt.Sprintf("%s:%d", cfg.SMTPConfig.Host, cfg.SMTPConfig.Port),
+		from:        cfg.SMTPConfig.From,
+		auth:        auth,
+		template:    t,
+	}, nil
+}
+
+type sender struct {
+	hostAddress string
+	from        string
+	auth        smtp.Auth
+	template    *template.Template
+}
+
+// loadTemplates loads html templates for use in emails
+func loadTemplates(cfg *config.Config) (*template.Template, error) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return nil, fmt.Errorf("error getting current working directory: %s", err)
+	}
+
+	// look for all templates that start with 'email_'
+	tmPath := filepath.Join(cwd, fmt.Sprintf("%semail_*", cfg.TemplateConfig.BaseDir))
+	return template.ParseGlob(tmPath)
+}