try to receive attachments

utils/file.go

@@ -0,0 +1,35 @@
+package utils
+
+import (
+	"bytes"
+
+	"maunium.net/go/mautrix"
+)
+
+type File struct {
+	Name    string
+	Type    string
+	Length  int
+	Content []byte
+}
+
+func NewFile(name, contentType string, content []byte) *File {
+	file := &File{
+		Name:    name,
+		Type:    contentType,
+		Content: content,
+	}
+	file.Length = len(content)
+
+	return file
+}
+
+func (f *File) Convert() mautrix.ReqUploadMedia {
+	return mautrix.ReqUploadMedia{
+		ContentBytes:  f.Content,
+		Content:       bytes.NewReader(f.Content),
+		ContentLength: int64(f.Length),
+		ContentType:   f.Type,
+		FileName:      f.Name,
+	}
+}