package koushin import ( "bufio" "fmt" "sort" "strconv" "strings" "github.com/emersion/go-imap" imapclient "github.com/emersion/go-imap/client" "github.com/emersion/go-message" "github.com/emersion/go-message/charset" "github.com/emersion/go-message/textproto" ) func init() { imap.CharsetReader = charset.Reader } func (s *Server) connectIMAP() (*imapclient.Client, error) { var c *imapclient.Client var err error if s.imap.tls { c, err = imapclient.DialTLS(s.imap.host, nil) if err != nil { return nil, fmt.Errorf("failed to connect to IMAPS server: %v", err) } } else { c, err = imapclient.Dial(s.imap.host) if err != nil { return nil, fmt.Errorf("failed to connect to IMAP server: %v", err) } if !s.imap.insecure { if err := c.StartTLS(nil); err != nil { c.Close() return nil, fmt.Errorf("STARTTLS failed: %v", err) } } } return c, err } func listMailboxes(conn *imapclient.Client) ([]*imap.MailboxInfo, error) { ch := make(chan *imap.MailboxInfo, 10) done := make(chan error, 1) go func() { done <- conn.List("", "*", ch) }() var mailboxes []*imap.MailboxInfo for mbox := range ch { mailboxes = append(mailboxes, mbox) } if err := <-done; err != nil { return nil, fmt.Errorf("failed to list mailboxes: %v", err) } sort.Slice(mailboxes, func(i, j int) bool { return mailboxes[i].Name < mailboxes[j].Name }) return mailboxes, nil } func ensureMailboxSelected(conn *imapclient.Client, mboxName string) error { mbox := conn.Mailbox() if mbox == nil || mbox.Name != mboxName { if _, err := conn.Select(mboxName, false); err != nil { return fmt.Errorf("failed to select mailbox: %v", err) } } return nil } type imapMessage struct { *imap.Message } func textPartPath(bs *imap.BodyStructure) ([]int, bool) { if bs.Disposition != "" && !strings.EqualFold(bs.Disposition, "inline") { return nil, false } if strings.EqualFold(bs.MIMEType, "text") { return []int{1}, true } if !strings.EqualFold(bs.MIMEType, "multipart") { return nil, false } textPartNum := -1 for i, part := range bs.Parts { num := i + 1 if strings.EqualFold(part.MIMEType, "multipart") { if subpath, ok := textPartPath(part); ok { return append([]int{num}, subpath...), true } } if !strings.EqualFold(part.MIMEType, "text") { continue } var pick bool switch strings.ToLower(part.MIMESubType) { case "plain": pick = true case "html": pick = textPartNum < 0 } if pick { textPartNum = num } } if textPartNum > 0 { return []int{textPartNum}, true } return nil, false } func (msg *imapMessage) TextPartName() string { if msg.BodyStructure == nil { return "" } path, ok := textPartPath(msg.BodyStructure) if !ok { return "" } l := make([]string, len(path)) for i, partNum := range path { l[i] = strconv.Itoa(partNum) } return strings.Join(l, ".") } type IMAPPartNode struct { Path []int MIMEType string Filename string Children []IMAPPartNode } func (node IMAPPartNode) PathString() string { l := make([]string, len(node.Path)) for i, partNum := range node.Path { l[i] = strconv.Itoa(partNum) } return strings.Join(l, ".") } func (node IMAPPartNode) IsText() bool { return strings.HasPrefix(strings.ToLower(node.MIMEType), "text/") } func (node IMAPPartNode) String() string { if node.Filename != "" { return fmt.Sprintf("%s (%s)", node.Filename, node.MIMEType) } else { return node.MIMEType } } func imapPartTree(bs *imap.BodyStructure, path []int) *IMAPPartNode { if !strings.EqualFold(bs.MIMEType, "multipart") && len(path) == 0 { path = []int{1} } var filename string if strings.EqualFold(bs.Disposition, "attachment") { filename = bs.DispositionParams["filename"] } node := &IMAPPartNode{ Path: path, MIMEType: strings.ToLower(bs.MIMEType + "/" + bs.MIMESubType), Filename: filename, Children: make([]IMAPPartNode, len(bs.Parts)), } for i, part := range bs.Parts { num := i + 1 partPath := append([]int(nil), path...) partPath = append(partPath, num) node.Children[i] = *imapPartTree(part, partPath) } return node } func (msg *imapMessage) PartTree() *IMAPPartNode { if msg.BodyStructure == nil { return nil } return imapPartTree(msg.BodyStructure, nil) } func listMessages(conn *imapclient.Client, mboxName string, page int) ([]imapMessage, error) { if err := ensureMailboxSelected(conn, mboxName); err != nil { return nil, err } mbox := conn.Mailbox() to := int(mbox.Messages) - page*messagesPerPage from := to - messagesPerPage + 1 if from <= 0 { from = 1 } if to <= 0 { return nil, nil } seqSet := new(imap.SeqSet) seqSet.AddRange(uint32(from), uint32(to)) fetch := []imap.FetchItem{imap.FetchEnvelope, imap.FetchUid, imap.FetchBodyStructure} ch := make(chan *imap.Message, 10) done := make(chan error, 1) go func() { done <- conn.Fetch(seqSet, fetch, ch) }() msgs := make([]imapMessage, 0, to-from) for msg := range ch { msgs = append(msgs, imapMessage{msg}) } if err := <-done; err != nil { return nil, fmt.Errorf("failed to fetch message list: %v", err) } // Reverse list of messages for i := len(msgs)/2 - 1; i >= 0; i-- { opp := len(msgs) - 1 - i msgs[i], msgs[opp] = msgs[opp], msgs[i] } return msgs, nil } func getMessagePart(conn *imapclient.Client, mboxName string, uid uint32, partPath []int) (*imapMessage, *message.Entity, error) { if err := ensureMailboxSelected(conn, mboxName); err != nil { return nil, nil, err } seqSet := new(imap.SeqSet) seqSet.AddNum(uid) var partHeaderSection imap.BodySectionName partHeaderSection.Peek = true if len(partPath) > 0 { partHeaderSection.Specifier = imap.MIMESpecifier } else { partHeaderSection.Specifier = imap.HeaderSpecifier } partHeaderSection.Path = partPath var partBodySection imap.BodySectionName partBodySection.Peek = true if len(partPath) > 0 { partBodySection.Specifier = imap.EntireSpecifier } else { partBodySection.Specifier = imap.TextSpecifier } partBodySection.Path = partPath fetch := []imap.FetchItem{ imap.FetchEnvelope, imap.FetchUid, imap.FetchBodyStructure, partHeaderSection.FetchItem(), partBodySection.FetchItem(), } ch := make(chan *imap.Message, 1) if err := conn.UidFetch(seqSet, fetch, ch); err != nil { return nil, nil, fmt.Errorf("failed to fetch message: %v", err) } msg := <-ch if msg == nil { return nil, nil, fmt.Errorf("server didn't return message") } headerReader := bufio.NewReader(msg.GetBody(&partHeaderSection)) h, err := textproto.ReadHeader(headerReader) if err != nil { return nil, nil, fmt.Errorf("failed to read part header: %v", err) } part, err := message.New(message.Header{h}, msg.GetBody(&partBodySection)) if err != nil { return nil, nil, fmt.Errorf("failed to create message reader: %v", err) } return &imapMessage{msg}, part, nil }