make maildir package more complete and fix some encoding bugs

mail.go

@@ -72,7 +72,7 @@ func readParts(reader io.Reader, boundary string, parts []Part) ([]Part, error)
 			if err != nil {
 				return nil, err
 			}
-			if strings.HasPrefix(mediaType, "text/") {
+			if strings.HasPrefix(mediaType, "text/plain") {
 				slurp = convertToUtf8(slurp)
 			}
 
@@ -390,6 +390,25 @@ func (m *Mail) Encode() (string, error) {
 	return buffer.String(), err
 }
 
+func addToMaildir(maildirPath string, content []byte) (filename string, err error) {
+	md, err := maildir.Open(maildirPath, true)
+	if err != nil {
+		return
+	}
+
+	msg, err := md.NewMessage(content)
+	if err != nil {
+		return
+	}
+	err = msg.SetFlags("S")
+	if err != nil {
+		return
+	}
+
+	filename, err = msg.Filename()
+	return
+}
+
 func sendMail(m *Mail) error {
 	addrl, err := m.Header.AddressList("From")
 	if len(addrl) != 1 {
@@ -426,7 +445,7 @@ func sendMail(m *Mail) error {
 		return err
 	}
 
-	filename, err := maildir.Store(expandEnvHome(account.Sent_Dir), []byte(mailcont), "S")
+	filename, err := addToMaildir(expandEnvHome(account.Sent_Dir), []byte(mailcont))
 	if err != nil {
 		return err
 	}

mailbuffer.go

@@ -12,6 +12,8 @@ import (
 	"os/exec"
 	"strings"
 
+	"github.com/paulrosania/go-charset/charset"
+	_ "github.com/paulrosania/go-charset/data"
 	"github.com/mattn/go-runewidth"
 	termbox "github.com/nsf/termbox-go"
 )
@@ -101,7 +103,7 @@ func formatPlain(buf []termbox.Cell, y, w int, text string) ([]termbox.Cell, int
 		if runeWidth == 0 || (runeWidth == 2 && runewidth.IsAmbiguousWidth(ch)) {
 			runeWidth = 1
 		}
-		x+=runeWidth
+		x += runeWidth
 	}
 
 	for ; x < w; x++ {
@@ -180,8 +182,8 @@ func (b *MailBuffer) refreshBuf() {
 
 func (b *MailBuffer) drawHeader() {
 	getHeader := func(key string) string {
-		dec := new(mime.WordDecoder)
-		str, err := dec.DecodeHeader(b.mail.Header.Get(key)) // ignore charset for now
+		dec := &mime.WordDecoder{charset.NewReader}
+		str, err := dec.DecodeHeader(b.mail.Header.Get(key))
 		if err != nil {
 			str = err.Error()
 		}

maildir/maildir.go

@@ -2,18 +2,24 @@
 // Use of this source code is governed by the MIT-styled
 // license that can be found in the LICENSE file.
 
-// Package maildir provides simple routines to add messages to a Maildir.
+// Package maildir provides methods for interacting with the Maildir format as specified at http://cr.yp.to/proto/maildir.html
 package maildir
 
 import (
 	"crypto/rand"
+	"errors"
 	"fmt"
 	"io"
 	"os"
 	"path/filepath"
+	"sort"
+	"strings"
 	"time"
 )
 
+var ErrorUnknownKey = errors.New("Key does not exist in Maildir.")
+var ErrorDuplicateKey = errors.New("Key exists more than once.")
+
 func key() (string, error) {
 	hostname, err := os.Hostname()
 	if err != nil {
@@ -30,47 +36,184 @@ func key() (string, error) {
 	return fmt.Sprintf("%v.M%vP%vR%x.%v", t.Unix(), t.Nanosecond()/1000, os.Getpid(), string(buf[:]), hostname), nil
 }
 
-// Store stores a message an a given maildir.
-// flags must be given as a sorted string of valid Maildir flags, e.g. "FRS".
-//
-// If flags is empty, the mail is stored in maidir/new. If not, it’s stored to maildir/cur.
-func Store(maildir string, mail []byte, flags string) (filename string, err error) {
-	_, err = os.Stat(maildir)
-	if err != nil {
-		return "", err
+func splitKeyFlags(filename string) (key, flags string, err error) {
+	splits := strings.Split(filepath.Base(filename), ":2,")
+	if len(splits) != 2 {
+		return "", "", errors.New("Mail filename format violation.")
+	}
+
+	return splits[0], splits[1], nil
+}
+
+func joinKeyFlags(key, flags string) string {
+	return key + ":2," + flags
+}
+
+// Dir represents a single Maildir folder.
+type Dir struct {
+	path string
+}
+
+// Open opens a maildir. Given create, if the "cur", "tmp", or "new" directories do not exist, they are created.
+func Open(path string, create bool) (md *Dir, err error) {
+	md = &Dir{path}
+	if !create {
+		return md, nil
+	}
+
+	err = os.Mkdir(path, os.ModeDir|0700)
+	if err != nil && !os.IsExist(err) {
+		return nil, fmt.Errorf("creating Maildir failed: %s", err)
+	}
+
+	err = os.Mkdir(filepath.Join(path, "new"), os.ModeDir|0700)
+	if err != nil && !os.IsExist(err) {
+		return nil, fmt.Errorf("creating Maildir failed: %s", err)
+	}
+
+	err = os.Mkdir(filepath.Join(path, "cur"), os.ModeDir|0700)
+	if err != nil && !os.IsExist(err) {
+		return nil, fmt.Errorf("creating Maildir failed: %s", err)
 	}
 
-	basename, err := key()
+	err = os.Mkdir(filepath.Join(path, "tmp"), os.ModeDir|0700)
+	if err != nil && !os.IsExist(err) {
+		return nil, fmt.Errorf("creating Maildir failed: %s", err)
+	}
+
+	return md, nil
+}
+
+// NewMessage writes a raw mail into the Maildir. After writing is complete, the corresponding file is moved to the "new" directory.
+func (md *Dir) NewMessage(mail []byte) (msg *Message, err error) {
+	msg = new(Message)
+
+	msg.md = md
+	msg.Key, err = key()
 	if err != nil {
-		return "", err
+		return nil, err
 	}
-	tmpname := filepath.Join(maildir, "tmp", basename)
+
+	tmpname := filepath.Join(md.path, "tmp", msg.Key)
 	file, err := os.Create(tmpname)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	size, err := file.Write(mail)
 	file.Close()
 	if err != nil {
 		os.Remove(tmpname)
-		return "", err
+		return nil, err
 	}
 
-	name := fmt.Sprintf("%s,S=%d", basename, size)
+	name := fmt.Sprintf("%s,S=%d", msg.Key, size)
 
 	target := "new"
-	if len(flags) != 0 {
-		target = "cur"
-		name += ":2," + flags
-	}
 
-	filename = filepath.Join(maildir, target, name)
-	err = os.Rename(tmpname, filename)
+	msg.filename = filepath.Join(md.path, target, name)
+	err = os.Rename(tmpname, msg.filename)
 	if err != nil {
 		os.Remove(tmpname)
+		return nil, err
+	}
+
+	return msg, nil
+}
+
+func (md *Dir) keyToFilename(key string) (filename string, err error) {
+	matches, err := filepath.Glob(filepath.Join(md.path, "[new,cur]", key+"*"))
+	if err != nil {
+		return "", err
+	}
+	if len(matches) == 0 {
+		return "", ErrorUnknownKey
+	}
+	if len(matches) > 1 {
+		return "", ErrorDuplicateKey
+	}
+
+	filename = matches[0]
+	return
+}
+
+// Get finds a message in the Maildir by its unique Key.
+func (md *Dir) Get(key string) (msg *Message, err error) {
+	fn, err := md.keyToFilename(key)
+	msg = &Message{key, fn, md}
+	return
+}
+
+// List returns a list of all messages in the Maildir
+func (md *Dir) List() (msgs []Message, err error) {
+	filenames, err := filepath.Glob(filepath.Join(md.path, "[new,cur]", "*"))
+	if err != nil {
+		return nil, err
+	}
+
+	msgs = make([]Message, len(filenames))
+
+	for i, f := range filenames {
+		msgs[i].Key, _, err = splitKeyFlags(f)
+		if err != nil {
+			return nil, err
+		}
+
+		msgs[i].filename = f
+		msgs[i].md = md
+	}
+
+	return msgs, nil
+}
+
+// Message represents a file in a Maildir.
+type Message struct {
+	// Key is a unique string identifying the message in the Maildir
+	Key string
+
+	// last known filename. May be invalid.
+	filename string
+
+	// Maildir the mail belongs to
+	md *Dir
+}
+
+// Flags returns the current flags stored in the message filename.
+func (msg *Message) Flags() (flags string, err error) {
+	fn, err := msg.Filename()
+	if err != nil {
 		return "", err
 	}
 
-	return filename, nil
+	_, flags, err = splitKeyFlags(fn)
+	return
+}
+
+// Filename returns the current path of the file containing Message.
+// Treat with caution as it may become invalid after flags are changed by another MUA for example.
+func (msg *Message) Filename() (string, error) {
+	_, err := os.Stat(msg.filename)
+	if err == nil {
+		return msg.filename, nil
+	}
+
+	return msg.md.keyToFilename(msg.Key)
+}
+
+// SetFlags sets the flags on a message and moves it into the "cur" directory (if not already).
+// newFlags is a string containing at most one letter of the flags defined by the specification: PRSTDF.
+func (msg *Message) SetFlags(newFlags string) error {
+	sortedFlags := []byte(newFlags)
+	sort.Slice(sortedFlags, func(i, j int) bool { return sortedFlags[i] < sortedFlags[j] })
+
+	filename, err := msg.Filename()
+	if err != nil {
+		return err
+	}
+
+	newFilename := filepath.Join(msg.md.path, "cur", joinKeyFlags(msg.Key, string(sortedFlags)))
+	err = os.Rename(filename, newFilename)
+	msg.filename = newFilename
+
+	return err
 }