maildir: move common maildir code out of worker

This change moves code that could be common to both notmuch and maildir
workers in worker/lib.

Signed-off-by: Julian Pidancet <julian.pidancet@oracle.com>
Acked-by: Robin Jarry <robin@jarry.cc>
Acked-by: Tim Culverhouse <tim@timculverhouse.com>

4 files changed, 172 insertions, 143 deletions

diff --git a/worker/lib/maildir.go b/worker/lib/maildir.go
new file mode 100644
index 00000000..f6199f9c
--- /dev/null
+++ b/worker/lib/maildir.go
@@ -0,0 +1,153 @@
+package lib
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"git.sr.ht/~rjarry/aerc/models"
+	"github.com/emersion/go-maildir"
+)
+
+type MaildirStore struct {
+	root      string
+	maildirpp bool // whether to use Maildir++ directory layout
+}
+
+func NewMaildirStore(root string, maildirpp bool) (*MaildirStore, error) {
+	f, err := os.Open(root)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	s, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
+	if !s.IsDir() {
+		return nil, fmt.Errorf("Given maildir '%s' not a directory", root)
+	}
+	return &MaildirStore{
+		root: root, maildirpp: maildirpp,
+	}, nil
+}
+
+// ListFolders returns a list of maildir folders in the container
+func (s *MaildirStore) ListFolders() ([]string, error) {
+	folders := []string{}
+	if s.maildirpp {
+		// In Maildir++ layout, INBOX is the root folder
+		folders = append(folders, "INBOX")
+	}
+	err := filepath.Walk(s.root, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return fmt.Errorf("Invalid path '%s': error: %w", path, err)
+		}
+		if !info.IsDir() {
+			return nil
+		}
+
+		// Skip maildir's default directories
+		n := info.Name()
+		if n == "new" || n == "tmp" || n == "cur" {
+			return filepath.SkipDir
+		}
+
+		// Get the relative path from the parent directory
+		dirPath, err := filepath.Rel(s.root, path)
+		if err != nil {
+			return err
+		}
+
+		// Skip the parent directory
+		if dirPath == "." {
+			return nil
+		}
+
+		// Drop dirs that lack {new,tmp,cur} subdirs
+		for _, sub := range []string{"new", "tmp", "cur"} {
+			if _, err := os.Stat(filepath.Join(path, sub)); os.IsNotExist(err) {
+				return nil
+			}
+		}
+
+		if s.maildirpp {
+			// In Maildir++ layout, mailboxes are stored in a single directory
+			// and prefixed with a dot, and subfolders are separated by dots.
+			if !strings.HasPrefix(dirPath, ".") {
+				return filepath.SkipDir
+			}
+			dirPath = strings.TrimPrefix(dirPath, ".")
+			dirPath = strings.ReplaceAll(dirPath, ".", "/")
+			folders = append(folders, dirPath)
+
+			// Since all mailboxes are stored in a single directory, don't
+			// recurse into subdirectories
+			return filepath.SkipDir
+		}
+
+		folders = append(folders, dirPath)
+		return nil
+	})
+	return folders, err
+}
+
+// Folder returns a maildir.Dir with the specified name inside the Store
+func (s *MaildirStore) Dir(name string) maildir.Dir {
+	if s.maildirpp {
+		// Use Maildir++ layout
+		if name == "INBOX" {
+			return maildir.Dir(s.root)
+		}
+		return maildir.Dir(filepath.Join(s.root, "."+strings.ReplaceAll(name, "/", ".")))
+	}
+	return maildir.Dir(filepath.Join(s.root, name))
+}
+
+// uidReg matches filename encoded UIDs in maildirs synched with mbsync or
+// OfflineIMAP
+var uidReg = regexp.MustCompile(`,U=\d+`)
+
+func StripUIDFromMessageFilename(basename string) string {
+	return uidReg.ReplaceAllString(basename, "")
+}
+
+var MaildirToFlag = map[maildir.Flag]models.Flag{
+	maildir.FlagReplied: models.AnsweredFlag,
+	maildir.FlagSeen:    models.SeenFlag,
+	maildir.FlagTrashed: models.DeletedFlag,
+	maildir.FlagFlagged: models.FlaggedFlag,
+	// maildir.FlagDraft Flag = 'D'
+	// maildir.FlagPassed Flag = 'P'
+}
+
+var FlagToMaildir = map[models.Flag]maildir.Flag{
+	models.AnsweredFlag: maildir.FlagReplied,
+	models.SeenFlag:     maildir.FlagSeen,
+	models.DeletedFlag:  maildir.FlagTrashed,
+	models.FlaggedFlag:  maildir.FlagFlagged,
+	// maildir.FlagDraft Flag = 'D'
+	// maildir.FlagPassed Flag = 'P'
+}
+
+func FromMaildirFlags(maildirFlags []maildir.Flag) []models.Flag {
+	var flags []models.Flag
+	for _, maildirFlag := range maildirFlags {
+		if flag, ok := MaildirToFlag[maildirFlag]; ok {
+			flags = append(flags, flag)
+		}
+	}
+	return flags
+}
+
+func ToMaildirFlags(flags []models.Flag) []maildir.Flag {
+	var maildirFlags []maildir.Flag
+	for _, flag := range flags {
+		if maildirFlag, ok := FlagToMaildir[flag]; ok {
+			maildirFlags = append(maildirFlags, maildirFlag)
+		}
+	}
+	return maildirFlags
+}
diff --git a/worker/maildir/container.go b/worker/maildir/container.go
index 4181648b..f9fb507b 100644
--- a/worker/maildir/container.go
+++ b/worker/maildir/container.go
@@ -4,108 +4,34 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"regexp"
 	"sort"
-	"strings"
 
 	"github.com/emersion/go-maildir"
 
 	"git.sr.ht/~rjarry/aerc/lib/uidstore"
+	"git.sr.ht/~rjarry/aerc/worker/lib"
 )
 
-// uidReg matches filename encoded UIDs in maildirs synched with mbsync or
-// OfflineIMAP
-var uidReg = regexp.MustCompile(`,U=\d+`)
-
 // A Container is a directory which contains other directories which adhere to
 // the Maildir spec
 type Container struct {
-	dir        string
+	Store      *lib.MaildirStore
 	uids       *uidstore.Store
 	recentUIDS map[uint32]struct{} // used to set the recent flag
-	maildirpp  bool                // whether to use Maildir++ directory layout
 }
 
 // NewContainer creates a new container at the specified directory
 func NewContainer(dir string, maildirpp bool) (*Container, error) {
-	f, err := os.Open(dir)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	s, err := f.Stat()
+	store, err := lib.NewMaildirStore(dir, maildirpp)
 	if err != nil {
 		return nil, err
 	}
-	if !s.IsDir() {
-		return nil, fmt.Errorf("Given maildir '%s' not a directory", dir)
-	}
 	return &Container{
-		dir: dir, uids: uidstore.NewStore(),
-		recentUIDS: make(map[uint32]struct{}), maildirpp: maildirpp,
+		Store: store, uids: uidstore.NewStore(),
+		recentUIDS: make(map[uint32]struct{}),
 	}, nil
 }
 
-// ListFolders returns a list of maildir folders in the container
-func (c *Container) ListFolders() ([]string, error) {
-	folders := []string{}
-	if c.maildirpp {
-		// In Maildir++ layout, INBOX is the root folder
-		folders = append(folders, "INBOX")
-	}
-	err := filepath.Walk(c.dir, func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return fmt.Errorf("Invalid path '%s': error: %w", path, err)
-		}
-		if !info.IsDir() {
-			return nil
-		}
-
-		// Skip maildir's default directories
-		n := info.Name()
-		if n == "new" || n == "tmp" || n == "cur" {
-			return filepath.SkipDir
-		}
-
-		// Get the relative path from the parent directory
-		dirPath, err := filepath.Rel(c.dir, path)
-		if err != nil {
-			return err
-		}
-
-		// Skip the parent directory
-		if dirPath == "." {
-			return nil
-		}
-
-		// Drop dirs that lack {new,tmp,cur} subdirs
-		for _, sub := range []string{"new", "tmp", "cur"} {
-			if _, err := os.Stat(filepath.Join(path, sub)); os.IsNotExist(err) {
-				return nil
-			}
-		}
-
-		if c.maildirpp {
-			// In Maildir++ layout, mailboxes are stored in a single directory
-			// and prefixed with a dot, and subfolders are separated by dots.
-			if !strings.HasPrefix(dirPath, ".") {
-				return filepath.SkipDir
-			}
-			dirPath = strings.TrimPrefix(dirPath, ".")
-			dirPath = strings.ReplaceAll(dirPath, ".", "/")
-			folders = append(folders, dirPath)
-
-			// Since all mailboxes are stored in a single directory, don't
-			// recurse into subdirectories
-			return filepath.SkipDir
-		}
-
-		folders = append(folders, dirPath)
-		return nil
-	})
-	return folders, err
-}
-
 // SyncNewMail adds emails from new to cur, tracking them
 func (c *Container) SyncNewMail(dir maildir.Dir) error {
 	keys, err := dir.Unseen()
@@ -122,25 +48,13 @@ func (c *Container) SyncNewMail(dir maildir.Dir) error {
 // OpenDirectory opens an existing maildir in the container by name, moves new
 // messages into cur, and registers the new keys in the UIDStore.
 func (c *Container) OpenDirectory(name string) (maildir.Dir, error) {
-	dir := c.Dir(name)
+	dir := c.Store.Dir(name)
 	if err := c.SyncNewMail(dir); err != nil {
 		return dir, err
 	}
 	return dir, nil
 }
 
-// Dir returns a maildir.Dir with the specified name inside the container
-func (c *Container) Dir(name string) maildir.Dir {
-	if c.maildirpp {
-		// Use Maildir++ layout
-		if name == "INBOX" {
-			return maildir.Dir(c.dir)
-		}
-		return maildir.Dir(filepath.Join(c.dir, "."+strings.ReplaceAll(name, "/", ".")))
-	}
-	return maildir.Dir(filepath.Join(c.dir, name))
-}
-
 // IsRecent returns if a uid has the Recent flag set
 func (c *Container) IsRecent(uid uint32) bool {
 	_, ok := c.recentUIDS[uid]
@@ -239,7 +153,7 @@ func (c *Container) moveMessage(dest maildir.Dir, src maildir.Dir, uid uint32) e
 		return fmt.Errorf("could not find path for message id %d", uid)
 	}
 	// Remove encoded UID information from the key to prevent sync issues
-	name := uidReg.ReplaceAllString(filepath.Base(path), "")
+	name := lib.StripUIDFromMessageFilename(filepath.Base(path))
 	destPath := filepath.Join(string(dest), "cur", name)
 	return os.Rename(path, destPath)
 }
diff --git a/worker/maildir/message.go b/worker/maildir/message.go
index 9cd13319..3c8ce9ef 100644
--- a/worker/maildir/message.go
+++ b/worker/maildir/message.go
@@ -33,7 +33,7 @@ func (m Message) ModelFlags() ([]models.Flag, error) {
 	if err != nil {
 		return nil, err
 	}
-	return translateMaildirFlags(flags), nil
+	return lib.FromMaildirFlags(flags), nil
 }
 
 // SetFlags replaces the message's flags with a new set.
@@ -91,44 +91,6 @@ func (m Message) NewBodyPartReader(requestedParts []int) (io.Reader, error) {
 	return lib.FetchEntityPartReader(msg, requestedParts)
 }
 
-var maildirToFlag = map[maildir.Flag]models.Flag{
-	maildir.FlagReplied: models.AnsweredFlag,
-	maildir.FlagSeen:    models.SeenFlag,
-	maildir.FlagTrashed: models.DeletedFlag,
-	maildir.FlagFlagged: models.FlaggedFlag,
-	// maildir.FlagDraft Flag = 'D'
-	// maildir.FlagPassed Flag = 'P'
-}
-
-var flagToMaildir = map[models.Flag]maildir.Flag{
-	models.AnsweredFlag: maildir.FlagReplied,
-	models.SeenFlag:     maildir.FlagSeen,
-	models.DeletedFlag:  maildir.FlagTrashed,
-	models.FlaggedFlag:  maildir.FlagFlagged,
-	// maildir.FlagDraft Flag = 'D'
-	// maildir.FlagPassed Flag = 'P'
-}
-
-func translateMaildirFlags(maildirFlags []maildir.Flag) []models.Flag {
-	var flags []models.Flag
-	for _, maildirFlag := range maildirFlags {
-		if flag, ok := maildirToFlag[maildirFlag]; ok {
-			flags = append(flags, flag)
-		}
-	}
-	return flags
-}
-
-func translateFlags(flags []models.Flag) []maildir.Flag {
-	var maildirFlags []maildir.Flag
-	for _, flag := range flags {
-		if maildirFlag, ok := flagToMaildir[flag]; ok {
-			maildirFlags = append(maildirFlags, maildirFlag)
-		}
-	}
-	return maildirFlags
-}
-
 func (m Message) UID() uint32 {
 	return m.uid
 }
diff --git a/worker/maildir/worker.go b/worker/maildir/worker.go
index ddb1bf68..d2bb6464 100644
--- a/worker/maildir/worker.go
+++ b/worker/maildir/worker.go
@@ -182,7 +182,7 @@ func (w *Worker) getDirectoryInfo(name string) *models.DirectoryInfo {
 		},
 	}
 
-	dir := w.c.Dir(name)
+	dir := w.c.Store.Dir(name)
 	var keyFlags map[string][]maildir.Flag
 	files, err := dirFiles(string(dir))
 	if err == nil {
@@ -329,7 +329,7 @@ func (w *Worker) handleListDirectories(msg *types.ListDirectories) error {
 	if w.c == nil {
 		return errors.New("Incorrect maildir directory")
 	}
-	dirs, err := w.c.ListFolders()
+	dirs, err := w.c.Store.ListFolders()
 	if err != nil {
 		logging.Errorf("failed listing directories: %v", err)
 		return err
@@ -453,7 +453,7 @@ func (w *Worker) sort(uids []uint32, criteria []*types.SortCriterion) ([]uint32,
 }
 
 func (w *Worker) handleCreateDirectory(msg *types.CreateDirectory) error {
-	dir := w.c.Dir(msg.Directory)
+	dir := w.c.Store.Dir(msg.Directory)
 	if err := dir.Init(); err != nil {
 		logging.Errorf("could not create directory %s: %v",
 			msg.Directory, err)
@@ -463,7 +463,7 @@ func (w *Worker) handleCreateDirectory(msg *types.CreateDirectory) error {
 }
 
 func (w *Worker) handleRemoveDirectory(msg *types.RemoveDirectory) error {
-	dir := w.c.Dir(msg.Directory)
+	dir := w.c.Store.Dir(msg.Directory)
 	if err := os.RemoveAll(string(dir)); err != nil {
 		logging.Errorf("could not remove directory %s: %v",
 			msg.Directory, err)
@@ -604,7 +604,7 @@ func (w *Worker) handleFlagMessages(msg *types.FlagMessages) error {
 			w.err(msg, err)
 			continue
 		}
-		flag := flagToMaildir[msg.Flag]
+		flag := lib.FlagToMaildir[msg.Flag]
 		if err := m.SetOneFlag(flag, msg.Enable); err != nil {
 			logging.Errorf("could change flag %v to %v on message: %v", flag, msg.Enable, err)
 			w.err(msg, err)
@@ -631,7 +631,7 @@ func (w *Worker) handleFlagMessages(msg *types.FlagMessages) error {
 }
 
 func (w *Worker) handleCopyMessages(msg *types.CopyMessages) error {
-	dest := w.c.Dir(msg.Destination)
+	dest := w.c.Store.Dir(msg.Destination)
 	err := w.c.CopyAll(dest, *w.selected, msg.Uids)
 	if err != nil {
 		return err
@@ -645,7 +645,7 @@ func (w *Worker) handleCopyMessages(msg *types.CopyMessages) error {
 }
 
 func (w *Worker) handleMoveMessages(msg *types.MoveMessages) error {
-	dest := w.c.Dir(msg.Destination)
+	dest := w.c.Store.Dir(msg.Destination)
 	moved, err := w.c.MoveAll(dest, *w.selected, msg.Uids)
 	destInfo := w.getDirectoryInfo(msg.Destination)
 	w.worker.PostMessage(&types.DirectoryInfo{
@@ -660,8 +660,8 @@ func (w *Worker) handleMoveMessages(msg *types.MoveMessages) error {
 
 func (w *Worker) handleAppendMessage(msg *types.AppendMessage) error {
 	// since we are the "master" maildir process, we can modify the maildir directly
-	dest := w.c.Dir(msg.Destination)
-	_, writer, err := dest.Create(translateFlags(msg.Flags))
+	dest := w.c.Store.Dir(msg.Destination)
+	_, writer, err := dest.Create(lib.ToMaildirFlags(msg.Flags))
 	if err != nil {
 		logging.Errorf("could not create message at %s: %v", msg.Destination, err)
 		return err
@@ -733,12 +733,12 @@ func (w *Worker) handleCheckMail(msg *types.CheckMail) {
 		if err != nil {
 			w.err(msg, fmt.Errorf("checkmail: error running command: %w", err))
 		} else {
-			dirs, err := w.c.ListFolders()
+			dirs, err := w.c.Store.ListFolders()
 			if err != nil {
 				w.err(msg, fmt.Errorf("failed listing directories: %w", err))
 			}
 			for _, name := range dirs {
-				err := w.c.SyncNewMail(w.c.Dir(name))
+				err := w.c.SyncNewMail(w.c.Store.Dir(name))
 				if err != nil {
 					w.err(msg, fmt.Errorf("could not sync new mail: %w", err))
 				}