From c829408095faf8d9dc9f9025282627585d7b74f8 Mon Sep 17 00:00:00 2001
From: "Felipe M." <me@fmartingr.com>
Date: Sun, 24 Nov 2024 12:08:35 +0100
Subject: [PATCH] refactor: configuration into separate file

---
 cmd/smtp2shoutrrr/main.go | 46 ++++++++++-----------------------------
 config.go                 | 46 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 35 deletions(-)
 create mode 100644 config.go

diff --git a/cmd/smtp2shoutrrr/main.go b/cmd/smtp2shoutrrr/main.go
index 41bc0d2..ef2c937 100644
--- a/cmd/smtp2shoutrrr/main.go
+++ b/cmd/smtp2shoutrrr/main.go
@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -23,6 +22,8 @@ import (
 	"github.com/containrrr/shoutrrr"
 	"github.com/emersion/go-sasl"
 	"github.com/emersion/go-smtp"
+
+	"git.nakama.town/fmartingr/smtp2shoutrrr"
 )
 
 type ReceivedEmail struct {
@@ -82,39 +83,11 @@ func (re *ReceivedEmail) Body() (string, error) {
 	return re.body, nil
 }
 
-type Config struct {
-	Port       int
-	Recipients []ConfigRecipient
-}
-
-func (c *Config) SetDefaults() {
-	if c.Port == 0 {
-		c.Port = 11125
-	}
-}
-
-type ConfigRecipient struct {
-	Addresses []string // email addresses
-	Target    string   // shoutrrr address
-	targetURL *url.URL
-}
-
-func (cr ConfigRecipient) GetTargetURL() *url.URL {
-	if cr.targetURL == nil {
-		var err error
-		cr.targetURL, err = url.Parse(cr.Target)
-		if err != nil {
-			slog.Error("failed to parse shoutrrr target URL", slog.String("target", cr.Target), slog.String("err", err.Error()))
-		}
-	}
-	return cr.targetURL
-}
-
 var _ model.Server = (*smtpServer)(nil)
 
 type smtpServer struct {
 	backend *smtp.Server
-	config  Config
+	config  smtp2shoutrrr.Config
 }
 
 func (s *smtpServer) IsEnabled() bool {
@@ -131,7 +104,7 @@ func (s *smtpServer) Stop(ctx context.Context) error {
 	return s.backend.Shutdown(ctx)
 }
 
-func NewSMTPServer(config *Config) model.Server {
+func NewSMTPServer(config *smtp2shoutrrr.Config) model.Server {
 	be := &Backend{
 		config: config,
 	}
@@ -152,13 +125,14 @@ func NewSMTPServer(config *Config) model.Server {
 
 // The Backend implements SMTP server methods.
 type Backend struct {
-	config *Config
+	config *smtp2shoutrrr.Config
 }
 
 // NewSession is called after client greeting (EHLO, HELO).
 func (bkd *Backend) NewSession(c *smtp.Conn) (smtp.Session, error) {
 	return &Session{
 		forwarderFunc: bkd.forwardEmail,
+		config:        bkd.config,
 	}, nil
 }
 
@@ -200,6 +174,8 @@ type Session struct {
 	addresses []string
 	body      string
 
+	config *smtp2shoutrrr.Config
+
 	forwarderFunc func(ReceivedEmail) error
 }
 
@@ -212,8 +188,8 @@ func (s *Session) AuthMechanisms() []string {
 // Auth is the handler for supported authenticators.
 func (s *Session) Auth(mech string) (sasl.Server, error) {
 	return sasl.NewPlainServer(func(identity, username, password string) error {
-		if username != "username" || password != "password" {
-			return errors.New("Invalid username or password")
+		if username != s.config.Username && password != s.config.Password {
+			return fmt.Errorf("invalid credentials")
 		}
 		return nil
 	}), nil
@@ -256,7 +232,7 @@ func (s *Session) Logout() error {
 }
 
 func main() {
-	var config *Config
+	var config *smtp2shoutrrr.Config
 	configPath := "config.toml"
 
 	f, err := os.Open(configPath)
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..9a64e9f
--- /dev/null
+++ b/config.go
@@ -0,0 +1,46 @@
+package smtp2shoutrrr
+
+import (
+	"log/slog"
+	"net/url"
+)
+
+type Config struct {
+	Port       int
+	Username   string
+	Password   string
+	Recipients []ConfigRecipient
+}
+
+func (c *Config) SetDefaults() {
+	if c.Port == 0 {
+		c.Port = 11125
+	}
+
+	if c.Username == "" {
+		slog.Warn("no username provided, using default: username")
+		c.Username = "username"
+	}
+
+	if c.Password == "" {
+		slog.Warn("no password provided, using default: password")
+		c.Password = "password"
+	}
+}
+
+type ConfigRecipient struct {
+	Addresses []string // email addresses
+	Target    string   // shoutrrr address
+	targetURL *url.URL
+}
+
+func (cr ConfigRecipient) GetTargetURL() *url.URL {
+	if cr.targetURL == nil {
+		var err error
+		cr.targetURL, err = url.Parse(cr.Target)
+		if err != nil {
+			slog.Error("failed to parse shoutrrr target URL", slog.String("target", cr.Target), slog.String("err", err.Error()))
+		}
+	}
+	return cr.targetURL
+}