From 442ca833ea5c3d29730b05dea62f7158b816695a Mon Sep 17 00:00:00 2001
From: Nick Thomas <me@ur.gs>
Date: Thu, 8 Mar 2018 00:17:44 +0000
Subject: [PATCH] Gut the Session interface

---
 internal/smtp/msa.go      |  8 ++++----
 internal/smtp/mta.go      | 16 ++++++++++++----
 internal/smtp/receiver.go | 20 --------------------
 internal/smtp/sender.go   | 18 ++++++++----------
 internal/smtp/session.go  | 17 ++++++-----------
 5 files changed, 30 insertions(+), 49 deletions(-)
 delete mode 100644 internal/smtp/receiver.go

diff --git a/internal/smtp/msa.go b/internal/smtp/msa.go
index 8afd8e2..2ae0ae5 100644
--- a/internal/smtp/msa.go
+++ b/internal/smtp/msa.go
@@ -60,13 +60,13 @@ func (m *msa) Login(user, pass string) (smtp.User, error) {
 		return nil, fmt.Errorf("Login failed")
 	}
 
+	sid := atomic.AddUint64(&m.sid, uint64(1))
 	session := &Session{
-		ID:      atomic.AddUint64(&m.sid, uint64(1)),
-		Account: account,
-		Handler: &Sender{},
+		ID:      fmt.Sprintf("submission:%d", sid),
+		Handler: &sender{msa: m, account: account},
 	}
 
-	log.Printf("Beginning submission session %d for %s", session.ID, user)
+	log.Printf("Beginning session %d for username=%s", session.ID, account.Username)
 	// FIXME: TODO: Track ongoing sessions for termination or notifications
 
 	return session, nil
diff --git a/internal/smtp/mta.go b/internal/smtp/mta.go
index 451b468..87e86f5 100644
--- a/internal/smtp/mta.go
+++ b/internal/smtp/mta.go
@@ -3,6 +3,7 @@ package smtp
 import (
 	"context"
 	"fmt"
+	"io"
 	"log"
 	"sync/atomic"
 
@@ -58,14 +59,21 @@ func (m *mta) Login(user, pass string) (smtp.User, error) {
 }
 
 func (m *mta) AnonymousLogin() (smtp.User, error) {
+	sid := atomic.AddUint64(&m.sid, uint64(1))
 	session := &Session{
-		ID:      atomic.AddUint64(&m.sid, uint64(1)),
-		Account: nil,
-		Handler: &Receiver{},
+		ID:      fmt.Sprintf("smtp:%d", sid),
+		Handler: m,
 	}
 
-	log.Printf("Beginning SMTP session %d", session.ID)
+	log.Printf("Beginning session %d", session.ID)
 	// FIXME: TODO: Track ongoing sessions for termination or notifications
 
 	return session, nil
 }
+
+// User implementation for go-smtp after this point
+// Since only anonymous login is permitted, there's no need to introduce an
+// intermediary to track the logged-in user.
+func (m *mta) ServeSMTP(from string, to []string, r io.Reader) error {
+	return fmt.Errorf("Not yet implemented")
+}
diff --git a/internal/smtp/receiver.go b/internal/smtp/receiver.go
deleted file mode 100644
index 429ca48..0000000
--- a/internal/smtp/receiver.go
+++ /dev/null
@@ -1,20 +0,0 @@
-package smtp
-
-import (
-	"fmt"
-	"io"
-)
-
-type Receiver struct{}
-
-func (r *Receiver) Name() string {
-	return "smtp-starttls"
-}
-
-// It seems odd to have a Receiver called Send, but what we're looking for is an
-// attempt from an arbitrary source to send an email to known accounts.
-//
-// We might want to clean this interface
-func (r *Receiver) Send(from string, to []string, reader io.Reader) error {
-	return fmt.Errorf("Not yet implemented")
-}
diff --git a/internal/smtp/sender.go b/internal/smtp/sender.go
index c22a5e3..7646eb3 100644
--- a/internal/smtp/sender.go
+++ b/internal/smtp/sender.go
@@ -3,19 +3,17 @@ package smtp
 import (
 	"fmt"
 	"io"
+
+	"ur.gs/crockery/internal/store"
 )
 
-type Sender struct{}
-
-func (s *Sender) Name() string {
-	return "submission-starttls"
+// Submission requires the sender to be logged in, so this struct tracks the
+// logged-in account per-session
+type sender struct {
+	msa     *msa
+	account *store.Account
 }
 
-// We're looking for the email to be from a logged-in account, to anywhere
-// on the internet - including locally!
-//
-// Should we handle local delivery differently to remote delivery, or connect
-// to ourselves, i.e., from submission, to smtp?
-func (s *Sender) Send(from string, to []string, reader io.Reader) error {
+func (s *sender) ServeSMTP(from string, to []string, r io.Reader) error {
 	return fmt.Errorf("Not yet implemented")
 }
diff --git a/internal/smtp/session.go b/internal/smtp/session.go
index 0b3da11..bd1477e 100644
--- a/internal/smtp/session.go
+++ b/internal/smtp/session.go
@@ -5,19 +5,14 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
-
-	"ur.gs/crockery/internal/store"
 )
 
 type Handler interface {
-	Name() string
-	Send(from string, to []string, r io.Reader) error
+	ServeSMTP(from string, to []string, r io.Reader) error
 }
 
-// type Session implements the User interface for emersion/go-smtp
 type Session struct {
-	ID      uint64
-	Account *store.Account
+	ID      string
 	Handler Handler
 }
 
@@ -28,14 +23,14 @@ func (s *Session) Send(from string, to []string, r io.Reader) error {
 		return err
 	}
 
-	log.Printf("%s session %d for %s: from=%s, to=%s, r=<<EOF\n%s\nEOF", s.Handler.Name(), s.ID, s.Account.Username, from, to, string(data))
+	log.Printf("session=%d from=%s to=%s r=<<EOF\n%s\nEOF", s.ID, from, to, string(data))
 
-	memR := bytes.NewReader(data)
-	return s.Handler.Send(from, to, memR)
+	// TODO: a chain of middlewares here
+	return s.Handler.ServeSMTP(from, to, bytes.NewReader(data))
 }
 
 func (s *Session) Logout() error {
-	log.Printf("Ending %s session %d for %s", s.Handler.Name(), s.ID, s.Account.Username)
+	log.Printf("Ending session %d", s.ID)
 
 	return nil
 }