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package lib
import (
"bufio"
"bytes"
"io"
"mime"
"net/http"
"os"
"path/filepath"
"strings"
"git.sr.ht/~rjarry/aerc/log"
"github.com/emersion/go-message/mail"
"github.com/pkg/errors"
)
type Part struct {
MimeType string
Params map[string]string
Data []byte
}
func NewPart(mimetype string, params map[string]string, body io.Reader,
) (*Part, error) {
d, err := io.ReadAll(body)
if err != nil {
return nil, err
}
return &Part{
MimeType: mimetype,
Params: params,
Data: d,
}, nil
}
func (p *Part) NewReader() io.Reader {
return bytes.NewReader(p.Data)
}
type Attachment interface {
Name() string
WriteTo(w *mail.Writer) error
}
type FileAttachment struct {
path string
}
func NewFileAttachment(path string) *FileAttachment {
return &FileAttachment{
path,
}
}
func (fa *FileAttachment) Name() string {
return fa.path
}
func (fa *FileAttachment) WriteTo(w *mail.Writer) error {
f, err := os.Open(fa.path)
if err != nil {
return errors.Wrap(err, "os.Open")
}
defer f.Close()
reader := bufio.NewReader(f)
mimeType, params, err := FindMimeType(fa.path, reader)
if err != nil {
return errors.Wrap(err, "ParseMediaType")
}
filename := filepath.Base(fa.path)
params["name"] = filename
// set header fields
ah := mail.AttachmentHeader{}
ah.SetContentType(mimeType, params)
// setting the filename auto sets the content disposition
ah.SetFilename(filename)
aw, err := w.CreateAttachment(ah)
if err != nil {
return errors.Wrap(err, "CreateAttachment")
}
defer aw.Close()
if _, err := reader.WriteTo(aw); err != nil {
return errors.Wrap(err, "reader.WriteTo")
}
return nil
}
type PartAttachment struct {
part *Part
name string
}
func NewPartAttachment(part *Part, name string) *PartAttachment {
return &PartAttachment{
part,
name,
}
}
func (pa *PartAttachment) Name() string {
return pa.name
}
func (pa *PartAttachment) WriteTo(w *mail.Writer) error {
// set header fields
ah := mail.AttachmentHeader{}
ah.SetContentType(pa.part.MimeType, pa.part.Params)
// setting the filename auto sets the content disposition
ah.SetFilename(pa.Name())
aw, err := w.CreateAttachment(ah)
if err != nil {
return errors.Wrap(err, "CreateAttachment")
}
defer aw.Close()
if _, err := io.Copy(aw, pa.part.NewReader()); err != nil {
return errors.Wrap(err, "io.Copy")
}
return nil
}
// SetUtf8Charset sets the charset in a params map to UTF-8.
func SetUtf8Charset(origParams map[string]string) map[string]string {
params := make(map[string]string)
for k, v := range origParams {
switch strings.ToLower(k) {
case "charset":
log.Debugf("substitute charset %s with utf-8", v)
params[k] = "utf-8"
default:
params[k] = v
}
}
return params
}
func FindMimeType(filename string, reader *bufio.Reader) (string, map[string]string, error) {
// if we have an extension, prefer that instead of trying to sniff the header.
// That's generally more accurate than sniffing as lots of things are zip files
// under the hood, e.g. most office file types
ext := filepath.Ext(filename)
var mimeString string
if mimeString = mime.TypeByExtension(ext); mimeString == "" {
// Sniff the mime type since it's not in the database
// http.DetectContentType only cares about the first 512 bytes
head, err := reader.Peek(512)
if err != nil && err != io.EOF {
return "", map[string]string{}, errors.Wrap(err, "Peek")
}
mimeString = http.DetectContentType(head)
}
// mimeString can contain type and params (like text encoding),
// so we need to break them apart before passing them to the headers
return mime.ParseMediaType(mimeString)
}
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