imapmemserver: add namespaces

imapserver/imapmemserver/namespace.go

@@ -0,0 +1,188 @@
+package imapmemserver
+
+import (
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/emersion/go-imap/v2"
+	"github.com/emersion/go-imap/v2/imapserver"
+)
+
+type Namespace struct {
+	prefix string
+
+	mutex           sync.Mutex
+	mailboxes       map[string]*Mailbox
+	prevUidValidity uint32
+}
+
+func NewNamespace(prefix string) *Namespace {
+	return &Namespace{prefix: prefix}
+}
+
+func (ns *Namespace) mailboxLocked(name string) (*Mailbox, error) {
+	mbox := ns.mailboxes[name]
+	if mbox == nil {
+		return nil, &imap.Error{
+			Type: imap.StatusResponseTypeNo,
+			Code: imap.ResponseCodeNonExistent,
+			Text: "No such mailbox",
+		}
+	}
+	return mbox, nil
+}
+
+func (ns *Namespace) mailbox(name string) (*Mailbox, error) {
+	ns.mutex.Lock()
+	defer ns.mutex.Unlock()
+	return ns.mailboxLocked(name)
+}
+
+func (ns *Namespace) Status(name string, options *imap.StatusOptions) (*imap.StatusData, error) {
+	mbox, err := ns.mailbox(name)
+	if err != nil {
+		return nil, err
+	}
+	return mbox.StatusData(options), nil
+}
+
+func (ns *Namespace) List(w *imapserver.ListWriter, ref string, patterns []string, options *imap.ListOptions) error {
+	ns.mutex.Lock()
+	defer ns.mutex.Unlock()
+
+	// TODO: fail if ref doesn't exist
+
+	if len(patterns) == 0 {
+		return w.WriteList(&imap.ListData{
+			Attrs: []imap.MailboxAttr{imap.MailboxAttrNoSelect},
+			Delim: mailboxDelim,
+		})
+	}
+
+	var l []imap.ListData
+	for name, mbox := range ns.mailboxes {
+		match := false
+		for _, pattern := range patterns {
+			match = imapserver.MatchList(name, mailboxDelim, ref, pattern)
+			if match {
+				break
+			}
+		}
+		if !match {
+			continue
+		}
+
+		data := mbox.list(options)
+		if data != nil {
+			l = append(l, *data)
+		}
+	}
+
+	sort.Slice(l, func(i, j int) bool {
+		return l[i].Mailbox < l[j].Mailbox
+	})
+
+	for _, data := range l {
+		if err := w.WriteList(&data); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (ns *Namespace) Append(mailbox string, r imap.LiteralReader, options *imap.AppendOptions) (*imap.AppendData, error) {
+	mbox, err := ns.mailbox(mailbox)
+	if err != nil {
+		return nil, &imap.Error{
+			Type: imap.StatusResponseTypeNo,
+			Code: imap.ResponseCodeTryCreate,
+			Text: "No such mailbox",
+		}
+	}
+	return mbox.appendLiteral(r, options)
+}
+
+func (ns *Namespace) Create(name string, options *imap.CreateOptions) error {
+	ns.mutex.Lock()
+	defer ns.mutex.Unlock()
+
+	name = strings.TrimRight(name, string(mailboxDelim))
+
+	if ns.mailboxes[name] != nil {
+		return &imap.Error{
+			Type: imap.StatusResponseTypeNo,
+			Code: imap.ResponseCodeAlreadyExists,
+			Text: "Mailbox already exists",
+		}
+	}
+
+	// UIDVALIDITY must change if a mailbox is deleted and re-created with the
+	// same name.
+	ns.prevUidValidity++
+	ns.mailboxes[name] = NewMailbox(name, ns.prevUidValidity)
+	return nil
+}
+
+func (ns *Namespace) Delete(name string) error {
+	ns.mutex.Lock()
+	defer ns.mutex.Unlock()
+
+	if _, err := ns.mailboxLocked(name); err != nil {
+		return err
+	}
+
+	delete(ns.mailboxes, name)
+	return nil
+}
+
+func (ns *Namespace) Rename(oldName, newName string) error {
+	ns.mutex.Lock()
+	defer ns.mutex.Unlock()
+
+	newName = strings.TrimRight(newName, string(mailboxDelim))
+
+	mbox, err := ns.mailboxLocked(oldName)
+	if err != nil {
+		return err
+	}
+
+	if ns.mailboxes[newName] != nil {
+		return &imap.Error{
+			Type: imap.StatusResponseTypeNo,
+			Code: imap.ResponseCodeAlreadyExists,
+			Text: "Mailbox already exists",
+		}
+	}
+
+	mbox.rename(newName)
+	ns.mailboxes[newName] = mbox
+	delete(ns.mailboxes, oldName)
+	return nil
+}
+
+func (ns *Namespace) Subscribe(name string) error {
+	mbox, err := ns.mailbox(name)
+	if err != nil {
+		return err
+	}
+	mbox.SetSubscribed(true)
+	return nil
+}
+
+func (ns *Namespace) Unsubscribe(name string) error {
+	mbox, err := ns.mailbox(name)
+	if err != nil {
+		return err
+	}
+	mbox.SetSubscribed(false)
+	return nil
+}
+
+func (ns *Namespace) NamespaceDescriptor() *imap.NamespaceDescriptor {
+	return &imap.NamespaceDescriptor{
+		Prefix: ns.prefix,
+		Delim:  mailboxDelim,
+	}
+}