From a91b2654d961c99e927318f91703dffe4efd22f3 Mon Sep 17 00:00:00 2001
From: Nick Thomas <me@ur.gs>
Date: Mon, 5 Mar 2018 23:46:21 +0000
Subject: [PATCH] Add the beginnings of IMAP session management

---
 internal/imap/server.go  | 22 +++++++++++++++---
 internal/imap/session.go | 49 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 3 deletions(-)
 create mode 100644 internal/imap/session.go

diff --git a/internal/imap/server.go b/internal/imap/server.go
index 3834db5..1da9b1c 100644
--- a/internal/imap/server.go
+++ b/internal/imap/server.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"log"
+	"sync/atomic"
 
 	imapbackend "github.com/emersion/go-imap/backend"
 	imapserver "github.com/emersion/go-imap/server"
@@ -28,8 +29,10 @@ func NewServer(cancel context.CancelFunc, datastore store.Interface, starttls bo
 	out.server.TLSConfig = out.store.TLSConfig()
 
 	if starttls {
+		out.name = "imap-starttls"
 		out.server.Addr = ":143"
 	} else {
+		out.name = "imap-tls"
 		out.server.Addr = ":993"
 	}
 
@@ -37,10 +40,14 @@ func NewServer(cancel context.CancelFunc, datastore store.Interface, starttls bo
 }
 
 type concrete struct {
+	name     string
 	cancel   context.CancelFunc
 	store    store.Interface
 	server   *imapserver.Server
 	starttls bool
+
+	// Session IDs
+	sid uint64
 }
 
 func (c *concrete) Run() {
@@ -61,9 +68,18 @@ func (c *concrete) Run() {
 	c.cancel()
 }
 
-// backend implementation for go-smtp
-func (c *concrete) Login(string, string) (imapbackend.User, error) {
-	return nil, nil
+// backend implementation for go-imap
+func (c *concrete) Login(user, pass string) (imapbackend.User, error) {
+	// FIXME: TODO: Check for account existence and correct password(!)
+	session := &Session{
+		ID:          atomic.AddUint64(&c.sid, uint64(1)),
+		AccountName: user,
+		ServiceName: c.name,
+	}
+
+	log.Printf("Beginning %s session %d for %s", c.name, session.ID, user)
+
+	return session, nil
 }
 
 func (c *concrete) Close() error {
diff --git a/internal/imap/session.go b/internal/imap/session.go
new file mode 100644
index 0000000..55c9245
--- /dev/null
+++ b/internal/imap/session.go
@@ -0,0 +1,49 @@
+package imap
+
+import (
+	"fmt"
+	"log"
+
+	imapbackend "github.com/emersion/go-imap/backend"
+)
+
+var (
+	notImplemented = fmt.Errorf("Not yet implemented")
+)
+
+// type Session implements the User interface for emersion/go-imap
+type Session struct {
+	ID          uint64
+	AccountName string
+	ServiceName string
+}
+
+func (s *Session) Username() string {
+	return s.AccountName
+}
+
+func (s *Session) ListMailboxes(subscribed bool) ([]imapbackend.Mailbox, error) {
+	return nil, notImplemented
+}
+
+func (s *Session) GetMailbox(name string) (imapbackend.Mailbox, error) {
+	return nil, notImplemented
+}
+
+func (s *Session) CreateMailbox(name string) error {
+	return notImplemented
+}
+
+func (s *Session) DeleteMailbox(name string) error {
+	return notImplemented
+}
+
+func (s *Session) RenameMailbox(existingName, newName string) error {
+	return notImplemented
+}
+
+func (s *Session) Logout() error {
+	log.Printf("Ending %s session %d for %s", s.ServiceName, s.ID, s.AccountName)
+
+	return nil
+}