V2 alpha - initial version (#172)

Initial alpha codebase for version 2 of WireGuard Portal.
This version is considered unstable and incomplete (for example, no public REST API)! 
Use with care!


Fixes/Implements the following issues:
 - OAuth support #154, #1 
 - New Web UI with internationalisation support #98, #107, #89, #62
 - Postgres Support #49 
 - Improved Email handling #47, #119 
 - DNS Search Domain support #46 
 - Bugfixes #94, #48 

---------

Co-authored-by: Fabian Wechselberger <wechselbergerf@hotmail.com>

internal/app/mail/manager.go

@@ -0,0 +1,127 @@
+package mail
+
+import (
+	"context"
+	"fmt"
+	"github.com/h44z/wg-portal/internal/config"
+	"github.com/h44z/wg-portal/internal/domain"
+	"github.com/sirupsen/logrus"
+	"io"
+)
+
+type Manager struct {
+	cfg        *config.Config
+	tplHandler *TemplateHandler
+
+	mailer      Mailer
+	configFiles ConfigFileManager
+	users       UserDatabaseRepo
+	wg          WireguardDatabaseRepo
+}
+
+func NewMailManager(cfg *config.Config, mailer Mailer, configFiles ConfigFileManager, users UserDatabaseRepo, wg WireguardDatabaseRepo) (*Manager, error) {
+	tplHandler, err := newTemplateHandler(cfg.Web.ExternalUrl)
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize template handler: %w", err)
+	}
+
+	m := &Manager{
+		cfg:         cfg,
+		tplHandler:  tplHandler,
+		mailer:      mailer,
+		configFiles: configFiles,
+		users:       users,
+		wg:          wg,
+	}
+
+	return m, nil
+}
+
+func (m Manager) SendPeerEmail(ctx context.Context, linkOnly bool, peers ...domain.PeerIdentifier) error {
+	for _, peerId := range peers {
+		peer, err := m.wg.GetPeer(ctx, peerId)
+		if err != nil {
+			return fmt.Errorf("failed to fetch peer %s: %w", peerId, err)
+		}
+
+		if peer.UserIdentifier == "" {
+			logrus.Debugf("skipping peer email for %s, no user linked", peerId)
+			continue
+		}
+
+		user, err := m.users.GetUser(ctx, peer.UserIdentifier)
+		if err != nil {
+			logrus.Debugf("skipping peer email for %s, unable to fetch user: %v", peerId, err)
+			continue
+		}
+
+		if user.Email == "" {
+			logrus.Debugf("skipping peer email for %s, user has no mail address", peerId)
+			continue
+		}
+
+		err = m.sendPeerEmail(ctx, linkOnly, user, peer)
+		if err != nil {
+			return fmt.Errorf("failed to send peer email for %s: %w", peerId, err)
+		}
+	}
+
+	return nil
+}
+
+func (m Manager) sendPeerEmail(ctx context.Context, linkOnly bool, user *domain.User, peer *domain.Peer) error {
+	qrName := "WireGuardQRCode.png"
+	configName := peer.GetConfigFileName()
+
+	var (
+		txtMail, htmlMail io.Reader
+		err               error
+		mailOptions       domain.MailOptions
+	)
+	if linkOnly {
+		txtMail, htmlMail, err = m.tplHandler.GetConfigMail(user, "deep link TBD")
+		if err != nil {
+			return fmt.Errorf("failed to get mail body: %w", err)
+		}
+
+	} else {
+		peerConfig, err := m.configFiles.GetPeerConfig(ctx, peer.Identifier)
+		if err != nil {
+			return fmt.Errorf("failed to fetch peer config for %s: %w", peer.Identifier, err)
+		}
+
+		peerConfigQr, err := m.configFiles.GetPeerConfigQrCode(ctx, peer.Identifier)
+		if err != nil {
+			return fmt.Errorf("failed to fetch peer config QR code for %s: %w", peer.Identifier, err)
+		}
+
+		txtMail, htmlMail, err = m.tplHandler.GetConfigMailWithAttachment(user, configName, qrName)
+		if err != nil {
+			return fmt.Errorf("failed to get full mail body: %w", err)
+		}
+
+		mailOptions.Attachments = append(mailOptions.Attachments, domain.MailAttachment{
+			Name:        configName,
+			ContentType: "text/plain",
+			Data:        peerConfig,
+			Embedded:    false,
+		})
+		mailOptions.Attachments = append(mailOptions.Attachments, domain.MailAttachment{
+			Name:        qrName,
+			ContentType: "image/png",
+			Data:        peerConfigQr,
+			Embedded:    true,
+		})
+	}
+
+	txtMailStr, _ := io.ReadAll(txtMail)
+	htmlMailStr, _ := io.ReadAll(htmlMail)
+	mailOptions.HtmlBody = string(htmlMailStr)
+
+	err = m.mailer.Send(ctx, "WireGuard VPN Configuration", string(txtMailStr), []string{user.Email}, &mailOptions)
+	if err != nil {
+		return fmt.Errorf("failed to send mail: %w", err)
+	}
+
+	return nil
+}