package lib
import (
"bytes"
"errors"
"fmt"
"io"
"regexp"
"strings"
"time"
"git.sr.ht/~sircmpwn/aerc/models"
"github.com/emersion/go-message"
_ "github.com/emersion/go-message/charset"
"github.com/emersion/go-message/mail"
)
// RFC 1123Z regexp
var dateRe = regexp.MustCompile(`(((Mon|Tue|Wed|Thu|Fri|Sat|Sun))[,]?\s[0-9]{1,2})\s` +
`(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s` +
`([0-9]{4})\s([0-9]{2}):([0-9]{2})(:([0-9]{2}))?\s([\+|\-][0-9]{4})\s?`)
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 bufReader(part)
}
return FetchEntityPartReader(part, index[1:])
}
}
}
if index[0] != 1 {
return nil, fmt.Errorf("cannont return non-first part of non-multipart")
}
return bufReader(e)
}
//TODO: the UI doesn't seem to like readers which aren't buffers
func bufReader(e *message.Entity) (io.Reader, error) {
var buf bytes.Buffer
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 := parseDate(h)
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)
}
replyTo, err := parseAddressList(h, "reply-to")
if err != nil {
return nil, fmt.Errorf("could not read reply-to 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,
ReplyTo: replyTo,
To: to,
Cc: cc,
Bcc: bcc,
}, nil
}
// parseDate extends the built-in date parser with additional layouts which are
// non-conforming but appear in the wild.
func parseDate(h *mail.Header) (time.Time, error) {
t, parseErr := h.Date()
if parseErr == nil {
return t, nil
}
text, err := h.Text("date")
if err != nil {
return time.Time{}, errors.New("no date header")
}
// sometimes, no error occurs but the date is empty. In this case, guess time from received header field
if text == "" {
guess, err := h.Text("received")
if err != nil {
return time.Time{}, errors.New("no received header")
}
t, _ := time.Parse(time.RFC1123Z, dateRe.FindString(guess))
return t, nil
}
layouts := []string{
// X-Mailer: EarthLink Zoo Mail 1.0
"Mon, _2 Jan 2006 15:04:05 -0700 (GMT-07:00)",
}
for _, layout := range layouts {
if t, err := time.Parse(layout, text); err == nil {
return t, nil
}
}
return time.Time{}, fmt.Errorf("unrecognized date format: %s", t)
}
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 {
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)
Labels() ([]string, 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
}
labels, err := raw.Labels()
if err != nil {
return nil, err
}
return &models.MessageInfo{
BodyStructure: bs,
Envelope: env,
Flags: flags,
Labels: labels,
InternalDate: env.Date,
RFC822Headers: &mail.Header{msg.Header},
Size: 0,
Uid: raw.UID(),
}, nil
}
