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-rw-r--r--worker/lib/parse.go240
1 files changed, 240 insertions, 0 deletions
diff --git a/worker/lib/parse.go b/worker/lib/parse.go
new file mode 100644
index 0000000..9f9fa62
--- /dev/null
+++ b/worker/lib/parse.go
@@ -0,0 +1,240 @@
+package lib
+
+import (
+ "bytes"
+ "encoding/base64"
+ "fmt"
+ "io"
+ "mime/quotedprintable"
+ "strings"
+
+ "git.sr.ht/~sircmpwn/aerc/models"
+ "github.com/emersion/go-message"
+ _ "github.com/emersion/go-message/charset"
+ "github.com/emersion/go-message/mail"
+)
+
+func FetchEntityPartReader(e *message.Entity, index []int) (io.Reader, error) {
+ if len(index) < 1 {
+ return nil, fmt.Errorf("no part to read")
+ }
+ if mpr := e.MultipartReader(); mpr != nil {
+ idx := 0
+ for {
+ idx++
+ part, err := mpr.NextPart()
+ if err != nil {
+ return nil, err
+ }
+ if idx == index[0] {
+ rest := index[1:]
+ if len(rest) < 1 {
+ return fetchEntityReader(part)
+ }
+ return FetchEntityPartReader(part, index[1:])
+ }
+ }
+ }
+ if index[0] != 1 {
+ return nil, fmt.Errorf("cannont return non-first part of non-multipart")
+ }
+ return fetchEntityReader(e)
+}
+
+// fetchEntityReader makes an io.Reader for the given entity. Since the
+// go-message package decodes the body for us, and the UI expects to deal with
+// a reader whose bytes are encoded with the part's encoding, we are in the
+// interesting position of needing to re-encode the reader before sending it
+// off to the UI layer.
+//
+// TODO: probably change the UI to expect an already-decoded reader and decode
+// in the IMAP worker.
+func fetchEntityReader(e *message.Entity) (io.Reader, error) {
+ enc := e.Header.Get("content-transfer-encoding")
+ var buf bytes.Buffer
+
+ // base64
+ if strings.EqualFold(enc, "base64") {
+ wc := base64.NewEncoder(base64.StdEncoding, &buf)
+ defer wc.Close()
+ if _, err := io.Copy(wc, e.Body); err != nil {
+ return nil, fmt.Errorf("could not base64 encode: %v", err)
+ }
+ return &buf, nil
+ }
+
+ // quoted-printable
+ if strings.EqualFold(enc, "quoted-printable") {
+ wc := quotedprintable.NewWriter(&buf)
+ defer wc.Close()
+ if _, err := io.Copy(wc, e.Body); err != nil {
+ return nil, fmt.Errorf("could not quoted-printable encode: %v", err)
+ }
+ return &buf, nil
+ }
+
+ // other general encoding
+ if _, err := io.Copy(&buf, e.Body); err != nil {
+ return nil, err
+ }
+
+ return &buf, nil
+}
+
+// split a MIME type into its major and minor parts
+func splitMIME(m string) (string, string) {
+ parts := strings.Split(m, "/")
+ if len(parts) != 2 {
+ return parts[0], ""
+ }
+ return parts[0], parts[1]
+}
+
+func parseEntityStructure(e *message.Entity) (*models.BodyStructure, error) {
+ var body models.BodyStructure
+ contentType, ctParams, err := e.Header.ContentType()
+ if err != nil {
+ return nil, fmt.Errorf("could not parse content type: %v", err)
+ }
+ mimeType, mimeSubType := splitMIME(contentType)
+ body.MIMEType = mimeType
+ body.MIMESubType = mimeSubType
+ body.Params = ctParams
+ body.Description = e.Header.Get("content-description")
+ body.Encoding = e.Header.Get("content-transfer-encoding")
+ if cd := e.Header.Get("content-disposition"); cd != "" {
+ contentDisposition, cdParams, err := e.Header.ContentDisposition()
+ if err != nil {
+ return nil, fmt.Errorf("could not parse content disposition: %v", err)
+ }
+ body.Disposition = contentDisposition
+ body.DispositionParams = cdParams
+ }
+ body.Parts = []*models.BodyStructure{}
+ if mpr := e.MultipartReader(); mpr != nil {
+ for {
+ part, err := mpr.NextPart()
+ if err == io.EOF {
+ return &body, nil
+ } else if err != nil {
+ return nil, err
+ }
+ ps, err := parseEntityStructure(part)
+ if err != nil {
+ return nil, fmt.Errorf("could not parse child entity structure: %v", err)
+ }
+ body.Parts = append(body.Parts, ps)
+ }
+ }
+ return &body, nil
+}
+
+func parseEnvelope(h *mail.Header) (*models.Envelope, error) {
+ date, err := h.Date()
+ if err != nil {
+ return nil, fmt.Errorf("could not parse date header: %v", err)
+ }
+ from, err := parseAddressList(h, "from")
+ if err != nil {
+ return nil, fmt.Errorf("could not read from address: %v", err)
+ }
+ to, err := parseAddressList(h, "to")
+ if err != nil {
+ return nil, fmt.Errorf("could not read to address: %v", err)
+ }
+ cc, err := parseAddressList(h, "cc")
+ if err != nil {
+ return nil, fmt.Errorf("could not read cc address: %v", err)
+ }
+ bcc, err := parseAddressList(h, "bcc")
+ if err != nil {
+ return nil, fmt.Errorf("could not read bcc address: %v", err)
+ }
+ subj, err := h.Subject()
+ if err != nil {
+ return nil, fmt.Errorf("could not read subject: %v", err)
+ }
+ msgID, err := h.Text("message-id")
+ if err != nil {
+ return nil, fmt.Errorf("could not read message id: %v", err)
+ }
+ return &models.Envelope{
+ Date: date,
+ Subject: subj,
+ MessageId: msgID,
+ From: from,
+ To: to,
+ Cc: cc,
+ Bcc: bcc,
+ }, nil
+}
+
+func parseAddressList(h *mail.Header, key string) ([]*models.Address, error) {
+ var converted []*models.Address
+ addrs, err := h.AddressList(key)
+ if err != nil {
+ if hdr, err := h.Text(key); err != nil && strings.Index(hdr, "@") < 0 {
+ return []*models.Address{&models.Address{
+ Name: hdr,
+ }}, nil
+ }
+ return nil, err
+ }
+ for _, addr := range addrs {
+ parts := strings.Split(addr.Address, "@")
+ var mbox, host string
+ if len(parts) > 1 {
+ mbox = strings.Join(parts[0:len(parts)-1], "@")
+ host = parts[len(parts)-1]
+ } else {
+ mbox = addr.Address
+ }
+ converted = append(converted, &models.Address{
+ Name: addr.Name,
+ Mailbox: mbox,
+ Host: host,
+ })
+ }
+ return converted, nil
+}
+
+// RawMessage is an interface that describes a raw message
+type RawMessage interface {
+ NewReader() (io.Reader, error)
+ ModelFlags() ([]models.Flag, error)
+ UID() uint32
+}
+
+// MessageInfo populates a models.MessageInfo struct for the message.
+// based on the reader returned by NewReader
+func MessageInfo(raw RawMessage) (*models.MessageInfo, error) {
+ r, err := raw.NewReader()
+ if err != nil {
+ return nil, err
+ }
+ msg, err := message.Read(r)
+ if err != nil {
+ return nil, fmt.Errorf("could not read message: %v", err)
+ }
+ bs, err := parseEntityStructure(msg)
+ if err != nil {
+ return nil, fmt.Errorf("could not get structure: %v", err)
+ }
+ env, err := parseEnvelope(&mail.Header{msg.Header})
+ if err != nil {
+ return nil, fmt.Errorf("could not get envelope: %v", err)
+ }
+ flags, err := raw.ModelFlags()
+ if err != nil {
+ return nil, err
+ }
+ return &models.MessageInfo{
+ BodyStructure: bs,
+ Envelope: env,
+ Flags: flags,
+ InternalDate: env.Date,
+ RFC822Headers: &mail.Header{msg.Header},
+ Size: 0,
+ Uid: raw.UID(),
+ }, nil
+}