Files
proton-bridge/pkg/message/parser/part.go
2020-09-11 11:41:02 +02:00

83 lines
2.0 KiB
Go

// Copyright (c) 2020 Proton Technologies AG
//
// This file is part of ProtonMail Bridge.
//
// ProtonMail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ProtonMail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with ProtonMail Bridge. If not, see <https://www.gnu.org/licenses/>.
package parser
import (
"errors"
"unicode/utf8"
pmmime "github.com/ProtonMail/proton-bridge/pkg/mime"
"github.com/emersion/go-message"
"golang.org/x/net/html/charset"
"golang.org/x/text/encoding"
)
type Parts []*Part
type Part struct {
Header message.Header
Body []byte
children Parts
}
func (p *Part) Child(n int) (part *Part, err error) {
if len(p.children) < n {
return nil, errors.New("no such part")
}
return p.children[n-1], nil
}
func (p *Part) Children() Parts {
return p.children
}
func (p *Part) AddChild(child *Part) {
p.children = append(p.children, child)
}
func (p *Part) ConvertToUTF8() error {
if utf8.Valid(p.Body) {
return nil
}
t, params, err := p.Header.ContentType()
if err != nil {
return err
}
var decoder *encoding.Decoder
if knownCharset, ok := params["charset"]; !ok {
encoding, _, _ := charset.DetermineEncoding(p.Body, t)
decoder = encoding.NewDecoder()
} else if decoder, err = pmmime.SelectDecoder(knownCharset); err != nil {
return err
}
if p.Body, err = decoder.Bytes(p.Body); err != nil {
return err
}
// HELP: Is this okay? What about when the charset is embedded in structured text type eg html/xml?
params["charset"] = "utf-8"
p.Header.SetContentType(t, params)
return nil
}