move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/fileid/file_id.go

@@ -0,0 +1,131 @@
+package fileid
+
+import (
+	"io"
+
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+)
+
+// FileID represents parsed Telegram Bot API file_id.
+type FileID struct {
+	Type            Type
+	DC              int
+	ID              int64
+	AccessHash      int64
+	FileReference   []byte
+	URL             string
+	PhotoSizeSource PhotoSizeSource
+}
+
+const (
+	webLocationFlag   = 1 << 24
+	fileReferenceFlag = 1 << 25
+)
+
+func (f *FileID) decodeLatestFileID(b *bin.Buffer) error {
+	if len(b.Buf) < 1 {
+		return io.ErrUnexpectedEOF
+	}
+	var subVersion = b.Buf[len(b.Buf)-1]
+
+	typeID, err := b.Uint32()
+	if err != nil {
+		return errors.Wrap(err, "read type_id")
+	}
+
+	hasWebLocation := typeID&webLocationFlag != 0
+	hasReference := typeID&fileReferenceFlag != 0
+
+	typeID &^= webLocationFlag
+	typeID &^= fileReferenceFlag
+	if typeID >= uint32(lastType) {
+		return errors.Errorf("unknown type %d", typeID)
+	}
+	f.Type = Type(typeID)
+
+	{
+		dcID, err := b.Uint32()
+		if err != nil {
+			return errors.Wrap(err, "read dc_id")
+		}
+		f.DC = int(dcID)
+	}
+
+	if hasReference {
+		reference, err := b.Bytes()
+		if err != nil {
+			return errors.Wrap(err, "read file_reference")
+		}
+		f.FileReference = reference
+	}
+	if hasWebLocation {
+		url, err := b.String()
+		if err != nil {
+			return errors.Wrap(err, "read url")
+		}
+		f.URL = url
+		return nil
+	}
+
+	{
+		id, err := b.Long()
+		if err != nil {
+			return errors.Wrap(err, "read id")
+		}
+		f.ID = id
+	}
+
+	{
+		accessHash, err := b.Long()
+		if err != nil {
+			return errors.Wrap(err, "read access_hash")
+		}
+		f.AccessHash = accessHash
+	}
+
+	switch Type(typeID) {
+	case Thumbnail, Photo, ProfilePhoto:
+	default:
+		return nil
+	}
+
+	if err := f.PhotoSizeSource.decode(b, subVersion); err != nil {
+		return errors.Wrap(err, "decode photo_size")
+	}
+	return nil
+}
+
+func (f *FileID) encodeLatestFileID(b *bin.Buffer) {
+	hasWebLocation := f.URL != ""
+	hasReference := len(f.FileReference) != 0
+
+	{
+		typeID := f.Type
+		if hasWebLocation {
+			typeID |= webLocationFlag
+		}
+		if hasReference {
+			typeID |= fileReferenceFlag
+		}
+		b.PutUint32(uint32(typeID))
+	}
+	b.PutUint32(uint32(f.DC))
+	if hasReference {
+		b.PutBytes(f.FileReference)
+	}
+	if hasWebLocation {
+		b.PutString(f.URL)
+		return
+	}
+	b.PutLong(f.ID)
+	b.PutLong(f.AccessHash)
+
+	switch f.Type {
+	case Thumbnail, Photo, ProfilePhoto:
+		f.PhotoSizeSource.encode(b)
+	}
+
+	b.Buf = append(b.Buf, latestSubVersion)
+}