Correctly handle LISTMESSAGES and STATUS commands using SeqNum instead of UID

internal/imap/mailbox.go

@@ -45,15 +45,9 @@ func (m *Mailbox) Info() (*imap.MailboxInfo, error) {
 // This function does not affect the state of any messages in the mailbox. See
 // RFC 3501 section 6.3.10 for a list of items that can be requested.
 func (m *Mailbox) Status(items []string) (*imap.MailboxStatus, error) {
-	log.Printf("Mailbox(%v).Status(%#v)", m.stored.Rel(), items)
+	status, err := m.buildStatus(items...)
-
+	log.Printf("Mailbox(%v).Status(%#v): %#v %#v", m.stored.Rel(), items, status, err)
-	return &imap.MailboxStatus{
+	return status, err
-		Name:           m.Name(),
-		Flags:          []string{}, // FIXME: what do we need here?
-		PermanentFlags: []string{}, // FIXME: what do we need here?
-		//UnseenSeqNum: 0, // FIXME: what do we need here? What even is a seqnum?
-		Messages: 1, // FIXME: hardcoded
-	}, nil
 }
 
 // SetSubscribed adds or removes the mailbox to the server's set of "active"
@@ -85,7 +79,7 @@ func (m *Mailbox) ListMessages(uid bool, seqset *imap.SeqSet, items []string, ch
 
 	var messages []store.Message
 	for _, set := range seqset.Set {
-		msgs, err := m.session.store.FindMessagesInRange(
+		msgs, err := m.session.store.FindMessagesInRangeBySeqNum(
 			m.stored, uint64(set.Start), uint64(set.Stop),
 		)
 
@@ -119,14 +113,13 @@ func (m *Mailbox) ListMessages(uid bool, seqset *imap.SeqSet, items []string, ch
 
 		body := map[*imap.BodySectionName]imap.Literal{}
 
-		imapMsg := imap.NewMessage(uint32(message.UID), items)
+		imapMsg := imap.NewMessage(uint32(message.SeqNum), items)
-		if err := fillItems(imapMsg, message); err != nil {
+		if err := m.fillMessageItems(imapMsg, message); err != nil {
 			return err
 		}
 
 		imapMsg.Envelope = envelope
 		imapMsg.Body = body
-		imapMsg.Uid = uint32(message.UID)
 		imapMsg.Size = uint32(message.Len())
 
 		log.Printf("	Sending message %#v", imapMsg)
@@ -137,14 +130,50 @@ func (m *Mailbox) ListMessages(uid bool, seqset *imap.SeqSet, items []string, ch
 	return nil
 }
 
-func fillItems(imapMsg *imap.Message, msg store.Message) error {
+func (m *Mailbox) buildStatus(items ...string) (*imap.MailboxStatus, error) {
+	out := &imap.MailboxStatus{
+		Name: m.Name(),
+	}
+
+	for _, item := range items {
+		switch item {
+		case "FLAGS": // TODO: ???
+			out.Flags = []string{}
+		case "PERMANENTFLAGS": // TODO: ???
+			out.PermanentFlags = []string{}
+		// The number of messages in the mailbox.
+		case "MESSAGES":
+			out.Messages = uint32(m.session.store.CountMessages(m.stored))
+		// The number of messages with the \Recent flag set. TODO
+		case "RECENT":
+		// The next unique identifier value of the mailbox.
+		case "UIDNEXT":
+			out.UidNext = uint32(m.stored.NextUID())
+		// The unique identifier validity value of the mailbox
+		case "UIDVALIDITY":
+			out.UidValidity = uint32(m.stored.UIDValidity())
+		// The number of messages which do not have the \Seen flag set. TODO
+		case "UNSEEN":
+		default:
+			return nil, fmt.Errorf("Unknown status item: %v", item)
+		}
+	}
+
+	return out, nil
+}
+
+func (m *Mailbox) fillMessageItems(imapMsg *imap.Message, msg store.Message) error {
+	// FIXME: do I have to fill Items as well as the individual fields? Unclear
 	for k, _ := range imapMsg.Items {
 		switch k {
 		case "UID":
-			imapMsg.Items[k] = msg.UID
+			imapMsg.Uid = uint32(msg.UID)
+			imapMsg.Items[k] = uint32(msg.UID)
 		case "FLAGS":
+			imapMsg.Flags = []string{}
 			imapMsg.Items[k] = []string{}
 		case "RFC822.SIZE":
+			imapMsg.Size = uint32(msg.Len())
 			imapMsg.Items[k] = uint32(msg.Len())
 		case "RFC822.HEADER":
 			str, err := msg.HeaderString()
@@ -154,7 +183,7 @@ func fillItems(imapMsg *imap.Message, msg store.Message) error {
 
 			imapMsg.Items[k] = str
 		default:
-			return fmt.Errorf("Unknown item: %v", k)
+			return fmt.Errorf("Unknown message item: %v", k)
 		}
 	}
 

internal/imap/uidlist/entry.go

@@ -7,8 +7,10 @@ import (
 )
 
 type Entry struct {
-	UID               uint64
+	UID    uint64
-	Extra             map[string][]string
+	SeqNum uint64
+	Extra  map[string][]string
+
 	LastKnownFilename string
 }
 

internal/imap/uidlist/uidlist.go

@@ -83,6 +83,12 @@ func handleFile(filename string, flags int) (*List, error) {
 	}, nil
 }
 
+func (l *List) NextUID() uint64 {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+
+	return l.header.NextUID
+}
 func (l *List) UIDValidity() uint64 {
 	return l.header.UIDValidity
 }
@@ -95,11 +101,35 @@ func (l *List) Entries() []Entry {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
 
-	// FIXME: use copy() ?
 	return l.entries
 }
 
-func (l *List) EntriesInRange(start, end uint64) []Entry {
+func (l *List) EntriesInRangeBySeqNum(start, end uint64) []Entry {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+
+	// IMAP SeqNums are indexed from 1. So 0 should be invalid, right?
+	if start == 0 {
+		return nil
+	}
+
+	start--
+	if int(start) > len(l.entries) {
+		return nil
+	}
+
+	if end == 0 {
+		return l.entries[start:]
+	}
+
+	if int(end) > len(l.entries) {
+		end = uint64(len(l.entries))
+	}
+
+	return l.entries[start:end]
+}
+
+func (l *List) EntriesInRangeByUID(start, end uint64) []Entry {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
 
@@ -124,6 +154,13 @@ func (l *List) Entry(key string) *Entry {
 	return nil
 }
 
+func (l *List) Count() uint64 {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+
+	return uint64(len(l.entries))
+}
+
 func (l *List) Append(filenames ...string) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()

internal/store/maildir.go

@@ -16,7 +16,8 @@ type MaildirInterface interface {
 	CreateMaildir(*Maildir) error
 	FindMaildir(account Account, name string) (Maildir, error)
 	FindMaildirs(account Account) ([]Maildir, error)
-	FindMessagesInRange(m Maildir, start, end uint64) ([]Message, error)
+	FindMessagesInRangeBySeqNum(m Maildir, start, end uint64) ([]Message, error)
+	CountMessages(m Maildir) uint64
 }
 
 type Maildir struct {
@@ -41,6 +42,14 @@ func (m *Maildir) Header(key string) (mail.Header, error) {
 	return m.filesystem.Header(key)
 }
 
+func (m *Maildir) UIDValidity() uint64 {
+	return m.uids.UIDValidity()
+}
+
+func (m *Maildir) NextUID() uint64 {
+	return m.uids.NextUID()
+}
+
 func (c *concrete) CreateMaildir(m *Maildir) error {
 	if m.directory == "" {
 		m.directory = c.buildMaildirPath(m.Account, m.Name)
@@ -130,13 +139,14 @@ func (c *concrete) buildMaildirPath(account Account, parts ...string) string {
 	return filepath.Join(bits...)
 }
 
-func (c *concrete) FindMessagesInRange(m Maildir, start, end uint64) ([]Message, error) {
+func (c *concrete) FindMessagesInRangeBySeqNum(m Maildir, start, end uint64) ([]Message, error) {
 	var out []Message
-	entries := m.uids.EntriesInRange(start, end)
+	entries := m.uids.EntriesInRangeBySeqNum(start, end)
 
 	for _, entry := range entries {
 		msg := Message{
 			UID:     entry.UID,
+			SeqNum:  entry.SeqNum,
 			Maildir: m,
 			Key:     entry.Key(),
 		}
@@ -146,3 +156,7 @@ func (c *concrete) FindMessagesInRange(m Maildir, start, end uint64) ([]Message,
 
 	return out, nil
 }
+
+func (c *concrete) CountMessages(m Maildir) uint64 {
+	return m.uids.Count()
+}

internal/store/message.go

@@ -13,6 +13,7 @@ type Message struct {
 	Maildir Maildir // maildir.name
 
 	UID      uint64
+	SeqNum   uint64
 	Key      string
 	Data     io.ReadCloser
 	hdrCache mail.Header