package koushinbase import ( "bufio" "bytes" "fmt" "sort" "strconv" "strings" "time" "github.com/emersion/go-imap" imapspecialuse "github.com/emersion/go-imap-specialuse" imapclient "github.com/emersion/go-imap/client" "github.com/emersion/go-message" "github.com/emersion/go-message/textproto" ) 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 } type mailboxType int const ( mailboxSent mailboxType = iota mailboxDrafts ) func getMailboxByType(conn *imapclient.Client, mboxType mailboxType) (*imap.MailboxInfo, error) { ch := make(chan *imap.MailboxInfo, 10) done := make(chan error, 1) go func() { done <- conn.List("", "%", ch) }() // TODO: configurable fallback names? var attr string var fallbackNames []string switch mboxType { case mailboxSent: attr = imapspecialuse.Sent fallbackNames = []string{"Sent"} case mailboxDrafts: attr = imapspecialuse.Drafts fallbackNames = []string{"Draft", "Drafts"} } var attrMatched bool var best *imap.MailboxInfo for mbox := range ch { for _, a := range mbox.Attributes { if attr == a { best = mbox attrMatched = true break } } if attrMatched { break } for _, fallback := range fallbackNames { if strings.EqualFold(fallback, mbox.Name) { best = mbox break } } } if err := <-done; err != nil { return nil, fmt.Errorf("failed to get mailbox with attribute %q: %v", attr, err) } return best, 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 (msg *IMAPMessage) TextPartName() string { if msg.BodyStructure == nil { return "" } var best []int isTextPlain := false msg.BodyStructure.Walk(func(path []int, part *imap.BodyStructure) bool { if !strings.EqualFold(part.MIMEType, "text") { return true } if part.Disposition != "" && !strings.EqualFold(part.Disposition, "inline") { return true } switch strings.ToLower(part.MIMESubType) { case "plain": isTextPlain = true best = path case "html": if !isTextPlain { best = path } } return true }) if best == nil { return "" } l := make([]string, len(best)) for i, partNum := range best { l[i] = strconv.Itoa(partNum) } return strings.Join(l, ".") } func (msg *IMAPMessage) Attachments() []IMAPPartNode { if msg.BodyStructure == nil { return nil } var attachments []IMAPPartNode msg.BodyStructure.Walk(func(path []int, part *imap.BodyStructure) bool { if !strings.EqualFold(part.Disposition, "attachment") { return true } filename, _ := part.Filename() attachments = append(attachments, IMAPPartNode{ Path: path, MIMEType: strings.ToLower(part.MIMEType + "/" + part.MIMESubType), Filename: filename, }) return true }) return attachments } 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} } filename, _ := bs.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 (msg *IMAPMessage) HasFlag(flag string) bool { for _, f := range msg.Flags { if imap.CanonicalFlag(f) == flag { return true } } return false } func listMessages(conn *imapclient.Client, mboxName string, page, messagesPerPage 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 } var seqSet imap.SeqSet seqSet.AddRange(uint32(from), uint32(to)) fetch := []imap.FetchItem{imap.FetchFlags, 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 searchCriteriaHeader(k, v string) *imap.SearchCriteria { return &imap.SearchCriteria{ Header: map[string][]string{ k: []string{v}, }, } } func searchCriteriaOr(criteria ...*imap.SearchCriteria) *imap.SearchCriteria { or := criteria[0] for _, c := range criteria[1:] { or = &imap.SearchCriteria{ Or: [][2]*imap.SearchCriteria{{or, c}}, } } return or } func searchMessages(conn *imapclient.Client, mboxName, query string, page, messagesPerPage int) (msgs []IMAPMessage, total int, err error) { if err := ensureMailboxSelected(conn, mboxName); err != nil { return nil, 0, err } // TODO: full-text search on demand (can be slow) //criteria := &imap.SearchCriteria{Text: []string{query}} criteria := searchCriteriaOr( searchCriteriaHeader("From", query), searchCriteriaHeader("To", query), searchCriteriaHeader("Cc", query), searchCriteriaHeader("Subject", query), ) nums, err := conn.Search(criteria) if err != nil { return nil, 0, fmt.Errorf("UID SEARCH failed: %v", err) } total = len(nums) from := page * messagesPerPage to := from + messagesPerPage if from >= len(nums) { return nil, total, nil } if to > len(nums) { to = len(nums) } nums = nums[from:to] indexes := make(map[uint32]int) for i, num := range nums { indexes[num] = i } var seqSet imap.SeqSet seqSet.AddNum(nums...) 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, len(nums)) for msg := range ch { i, ok := indexes[msg.SeqNum] if !ok { continue } msgs[i] = IMAPMessage{msg} } if err := <-done; err != nil { return nil, 0, fmt.Errorf("failed to fetch message list: %v", err) } return msgs, total, 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, imap.FetchFlags, 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 } func markMessageAnswered(conn *imapclient.Client, mboxName string, uid uint32) error { if err := ensureMailboxSelected(conn, mboxName); err != nil { return err } seqSet := new(imap.SeqSet) seqSet.AddNum(uid) item := imap.FormatFlagsOp(imap.AddFlags, true) flags := []interface{}{imap.AnsweredFlag} return conn.UidStore(seqSet, item, flags, nil) } func appendMessage(c *imapclient.Client, msg *OutgoingMessage, mboxType mailboxType) (saved bool, err error) { mbox, err := getMailboxByType(c, mboxType) if err != nil { return false, err } if mbox == nil { return false, nil } // IMAP needs to know in advance the final size of the message, so // there's no way around storing it in a buffer here. var buf bytes.Buffer if err := msg.WriteTo(&buf); err != nil { return false, err } flags := []string{imap.SeenFlag} if mboxType == mailboxDrafts { flags = append(flags, imap.DraftFlag) } if err := c.Append(mbox.Name, flags, time.Now(), &buf); err != nil { return false, err } return true, nil } func deleteMessage(c *imapclient.Client, mboxName string, uid uint32) error { if err := ensureMailboxSelected(c, mboxName); err != nil { return err } seqSet := new(imap.SeqSet) seqSet.AddNum(uid) item := imap.FormatFlagsOp(imap.AddFlags, true) flags := []interface{}{imap.DeletedFlag} if err := c.UidStore(seqSet, item, flags, nil); err != nil { return err } return c.Expunge(nil) }