add osc bundle encoding with proper timetag

pkg/osc/bundle.go

@@ -1,12 +1,14 @@
 package osc
 
-import "encoding/binary"
+import (
+	"errors"
+)
 
 func (b *OSCBundle) ToBytes() []byte {
 
 	bytes := stringToOSCBytes("#bundle")
 
-	bytes = binary.BigEndian.AppendUint64(bytes, b.TimeTag)
+	bytes = append(bytes, timeTagToOSCBytes(b.TimeTag)...)
 
 	for _, packet := range b.Contents {
 		packetBytes := packet.ToBytes()
@@ -18,3 +20,76 @@ func (b *OSCBundle) ToBytes() []byte {
 
 	return bytes
 }
+
+func BundleFromBytes(bytes []byte) (OSCBundle, []byte, error) {
+	if len(bytes) < 20 {
+		return OSCBundle{}, bytes, errors.New("bundle has to be at least 20 bytes")
+	}
+
+	if bytes[0] != 35 {
+		return OSCBundle{}, bytes, errors.New("bundle must start with a #")
+	}
+
+	bundleHeader, bytesAfterBundleHeader := readOSCString(bytes)
+
+	if bundleHeader != "#bundle" {
+		return OSCBundle{}, bytesAfterBundleHeader, errors.New("bundle must start with #bundle string")
+	}
+
+	timeTag, bytesAfterTimeTag, err := readOSCTimeTag(bytesAfterBundleHeader)
+
+	if err != nil {
+		return OSCBundle{}, bytesAfterBundleHeader, err
+	}
+
+	bundleContents := []OSCPacket{}
+
+	endOfBundle := false
+
+	remainingBytes := bytesAfterTimeTag
+
+	for !endOfBundle {
+		contentSize, bytesAfterContentSize, err := readOSCInt32(remainingBytes)
+
+		if err != nil {
+			return OSCBundle{}, remainingBytes, err
+		}
+
+		remainingBytes = bytesAfterContentSize
+
+		if len(remainingBytes) < int(contentSize) {
+			return OSCBundle{}, remainingBytes, errors.New("bundle doesn't have enough bytes for the content size it specifies")
+		}
+
+		bundleContentBytes := remainingBytes[0:contentSize]
+
+		if bundleContentBytes[0] == 35 {
+			content, _, err := BundleFromBytes(bundleContentBytes)
+			if err != nil {
+				return OSCBundle{}, remainingBytes, err
+			}
+			bundleContents = append(bundleContents, &content)
+		} else if bundleContentBytes[0] == 47 {
+			content, err := MessageFromBytes(bundleContentBytes)
+			if err != nil {
+				return OSCBundle{}, remainingBytes, err
+			}
+			bundleContents = append(bundleContents, &content)
+		} else {
+			return OSCBundle{}, remainingBytes, errors.New("bundle contents does not look a bundle or message")
+		}
+		remainingBytes = bytesAfterContentSize[contentSize:]
+		if len(remainingBytes) == 0 {
+			endOfBundle = true
+		}
+
+	}
+
+	return OSCBundle{
+			TimeTag:  timeTag,
+			Contents: bundleContents,
+		},
+		remainingBytes,
+		nil
+
+}