add email rotation regarding a limit

internal/command/rotate_email.go

@@ -0,0 +1,44 @@
+package command
+
+import (
+	"context"
+
+	"forge.cadoles.com/Cadoles/fake-smtp/internal/model"
+	"forge.cadoles.com/Cadoles/fake-smtp/internal/storm"
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/cqrs"
+	"gitlab.com/wpetit/goweb/middleware/container"
+)
+
+type RotateEmailRequest struct {
+	MaxEmail int
+}
+
+func HandleRotateEmail(ctx context.Context, cmd cqrs.Command) error {
+	req, ok := cmd.Request().(*RotateEmailRequest)
+	if !ok {
+		return cqrs.ErrUnexpectedRequest
+	}
+
+	ctn, err := container.From(ctx)
+	if err != nil {
+		return errors.Wrap(err, "could not retrieve service container")
+	}
+
+	db, err := storm.From(ctn)
+	if err != nil {
+		return errors.Wrap(err, "could not retrieve storm service")
+	}
+
+	emailCount, err := db.Select().Count(&model.Email{})
+	if err != nil {
+		return errors.Wrap(err, "could not count emails")
+	}
+
+	if emailCount >= req.MaxEmail {
+		var diff = emailCount - (req.MaxEmail - 1)
+		db.Select().OrderBy("ID").Limit(diff).Delete(&model.Email{})
+	}
+
+	return nil
+}