69 lines
1.4 KiB
Go
69 lines
1.4 KiB
Go
package backendutil
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"io"
|
|
|
|
"github.com/emersion/go-imap"
|
|
"github.com/emersion/go-message"
|
|
)
|
|
|
|
var errNoSuchPart = errors.New("backendutil: no such message body part")
|
|
|
|
// FetchBodySection extracts a body section from a message.
|
|
func FetchBodySection(e *message.Entity, section *imap.BodySectionName) (imap.Literal, error) {
|
|
// First, find the requested part using the provided path
|
|
for i := len(section.Path) - 1; i >= 0; i-- {
|
|
n := section.Path[i]
|
|
|
|
mr := e.MultipartReader()
|
|
if mr == nil {
|
|
return nil, errNoSuchPart
|
|
}
|
|
|
|
for j := 1; j <= n; j++ {
|
|
p, err := mr.NextPart()
|
|
if err == io.EOF {
|
|
return nil, errNoSuchPart
|
|
} else if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if j == n {
|
|
e = p
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
// Then, write the requested data to a buffer
|
|
b := new(bytes.Buffer)
|
|
|
|
// Write the header
|
|
mw, err := message.CreateWriter(b, e.Header)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer mw.Close()
|
|
|
|
// If the header hasn't been requested, discard it
|
|
if section.Specifier == imap.TextSpecifier {
|
|
b.Reset()
|
|
}
|
|
|
|
// Write the body, if requested
|
|
switch section.Specifier {
|
|
case imap.EntireSpecifier, imap.TextSpecifier:
|
|
if _, err := io.Copy(mw, e.Body); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
var l imap.Literal = b
|
|
if section.Partial != nil {
|
|
l = bytes.NewReader(section.ExtractPartial(b.Bytes()))
|
|
}
|
|
return l, nil
|
|
}
|