refactor: replace Get/Set patterns with idiomatic Go interfaces

- rename constructors to New
- remove Get/Set-style accessors
- replace string-based enums with iota-backed types

session/lifecycle/lifecycle.go

@@ -15,115 +15,119 @@ import (
 
 type Forwarder interface {
 	Close() error
-	GetTunnelType() types.TunnelType
-	GetForwardedPort() uint16
+	TunnelType() types.TunnelType
+	ForwardedPort() uint16
 }
 
 type SessionRegistry interface {
 	Remove(key types.SessionKey)
 }
 
-type Lifecycle struct {
+type lifecycle struct {
 	status          types.Status
 	conn            ssh.Conn
 	channel         ssh.Channel
 	forwarder       Forwarder
 	sessionRegistry SessionRegistry
-	slugManager     slug.Manager
+	slug            slug.Slug
 	startedAt       time.Time
 	user            string
 }
 
-func NewLifecycle(conn ssh.Conn, forwarder Forwarder, slugManager slug.Manager, user string) *Lifecycle {
-	return &Lifecycle{
+func New(conn ssh.Conn, forwarder Forwarder, slugManager slug.Slug, user string) Lifecycle {
+	return &lifecycle{
 		status:          types.INITIALIZING,
 		conn:            conn,
 		channel:         nil,
 		forwarder:       forwarder,
-		slugManager:     slugManager,
+		slug:            slugManager,
 		sessionRegistry: nil,
 		startedAt:       time.Now(),
 		user:            user,
 	}
 }
 
-func (l *Lifecycle) SetSessionRegistry(registry SessionRegistry) {
+func (l *lifecycle) SetSessionRegistry(registry SessionRegistry) {
 	l.sessionRegistry = registry
 }
 
-type SessionLifecycle interface {
-	Close() error
-	SetStatus(status types.Status)
-	GetConnection() ssh.Conn
-	GetChannel() ssh.Channel
-	GetUser() string
+type Lifecycle interface {
+	Connection() ssh.Conn
+	Channel() ssh.Channel
+	User() string
 	SetChannel(channel ssh.Channel)
 	SetSessionRegistry(registry SessionRegistry)
+	SetStatus(status types.Status)
 	IsActive() bool
 	StartedAt() time.Time
+	Close() error
 }
 
-func (l *Lifecycle) GetUser() string {
+func (l *lifecycle) User() string {
 	return l.user
 }
 
-func (l *Lifecycle) GetChannel() ssh.Channel {
+func (l *lifecycle) Channel() ssh.Channel {
 	return l.channel
 }
 
-func (l *Lifecycle) SetChannel(channel ssh.Channel) {
+func (l *lifecycle) SetChannel(channel ssh.Channel) {
 	l.channel = channel
 }
-func (l *Lifecycle) GetConnection() ssh.Conn {
+func (l *lifecycle) Connection() ssh.Conn {
 	return l.conn
 }
-func (l *Lifecycle) SetStatus(status types.Status) {
+func (l *lifecycle) SetStatus(status types.Status) {
 	l.status = status
 	if status == types.RUNNING && l.startedAt.IsZero() {
 		l.startedAt = time.Now()
 	}
 }
 
-func (l *Lifecycle) Close() error {
-	err := l.forwarder.Close()
-	if err != nil && !errors.Is(err, net.ErrClosed) {
-		return err
+func (l *lifecycle) Close() error {
+	var firstErr error
+	tunnelType := l.forwarder.TunnelType()
+
+	if err := l.forwarder.Close(); err != nil && !errors.Is(err, net.ErrClosed) {
+		firstErr = err
 	}
 
 	if l.channel != nil {
-		err := l.channel.Close()
-		if err != nil && !errors.Is(err, io.EOF) {
-			return err
+		if err := l.channel.Close(); err != nil && !errors.Is(err, io.EOF) && !errors.Is(err, net.ErrClosed) {
+			if firstErr == nil {
+				firstErr = err
+			}
 		}
 	}
 
 	if l.conn != nil {
-		err := l.conn.Close()
-		if err != nil && !errors.Is(err, net.ErrClosed) {
-			return err
+		if err := l.conn.Close(); err != nil && !errors.Is(err, net.ErrClosed) {
+			if firstErr == nil {
+				firstErr = err
+			}
 		}
 	}
 
-	clientSlug := l.slugManager.Get()
-	if clientSlug != "" && l.sessionRegistry.Remove != nil {
-		key := types.SessionKey{Id: clientSlug, Type: l.forwarder.GetTunnelType()}
-		l.sessionRegistry.Remove(key)
+	clientSlug := l.slug.String()
+	key := types.SessionKey{
+		Id:   clientSlug,
+		Type: tunnelType,
 	}
+	l.sessionRegistry.Remove(key)
 
-	if l.forwarder.GetTunnelType() == types.TCP {
-		err = portUtil.Default.SetPortStatus(l.forwarder.GetForwardedPort(), false)
-		if err != nil {
-			return err
+	if tunnelType == types.TCP {
+		if err := portUtil.Default.SetPortStatus(l.forwarder.ForwardedPort(), false); err != nil && firstErr == nil {
+			firstErr = err
 		}
 	}
 
-	return nil
+	return firstErr
 }
 
-func (l *Lifecycle) IsActive() bool {
+func (l *lifecycle) IsActive() bool {
 	return l.status == types.RUNNING
 }
 
-func (l *Lifecycle) StartedAt() time.Time {
+func (l *lifecycle) StartedAt() time.Time {
 	return l.startedAt
 }