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/*
GoToSocial
Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package media
import (
"bytes"
"errors"
"fmt"
"github.com/h2non/filetype"
)
// parseContentType parses the MIME content type from a file, returning it as a string in the form (eg., "image/jpeg").
// Returns an error if the content type is not something we can process.
func parseContentType(content []byte) (string, error) {
// read in the first bytes of the file
fileHeader := make([]byte, maxFileHeaderBytes)
if _, err := bytes.NewReader(content).Read(fileHeader); err != nil {
return "", fmt.Errorf("could not read first magic bytes of file: %s", err)
}
kind, err := filetype.Match(fileHeader)
if err != nil {
return "", err
}
if kind == filetype.Unknown {
return "", errors.New("filetype unknown")
}
return kind.MIME.Value, nil
}
// supportedImage checks mime type of an image against a slice of accepted types,
// and returns True if the mime type is accepted.
func supportedImage(mimeType string) bool {
acceptedImageTypes := []string{
mimeImageJpeg,
mimeImageGif,
mimeImagePng,
}
for _, accepted := range acceptedImageTypes {
if mimeType == accepted {
return true
}
}
return false
}
// supportedEmoji checks that the content type is image/png or image/gif -- the only types supported for emoji.
func supportedEmoji(mimeType string) bool {
acceptedEmojiTypes := []string{
mimeImageGif,
mimeImagePng,
}
for _, accepted := range acceptedEmojiTypes {
if mimeType == accepted {
return true
}
}
return false
}
// ParseMediaType converts s to a recognized MediaType, or returns an error if unrecognized
func ParseMediaType(s string) (Type, error) {
switch s {
case string(TypeAttachment):
return TypeAttachment, nil
case string(TypeHeader):
return TypeHeader, nil
case string(TypeAvatar):
return TypeAvatar, nil
case string(TypeEmoji):
return TypeEmoji, nil
}
return "", fmt.Errorf("%s not a recognized MediaType", s)
}
// ParseMediaSize converts s to a recognized MediaSize, or returns an error if unrecognized
func ParseMediaSize(s string) (Size, error) {
switch s {
case string(SizeSmall):
return SizeSmall, nil
case string(SizeOriginal):
return SizeOriginal, nil
case string(SizeStatic):
return SizeStatic, nil
}
return "", fmt.Errorf("%s not a recognized MediaSize", s)
}
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