static string Update(this ReportDescriptorData descriptor, byte header, int data)
{
var type = descriptor.GetType();
var field = type.GetFields().Single(p => p.GetCustomAttribute <TagAttribute>().Match(header));
field.SetValue(descriptor, data);
return(field.Name);
}
public static IEnumerable <ReportCollection> Parse(byte[] bytes)
{
using (var reader = new BinaryReader(new MemoryStream(bytes))) {
var descriptor = new ReportDescriptorData();
var descriptorStack = new Stack <ReportDescriptorData>();
ReportCollection collection = null;
while (reader.BaseStream.Position < bytes.Length)
{
var header = reader.ReadByte();
var size = 1 << (header & 0b11) >> 1;
var data = 0;
for (int i = 0; i < size; i++)
{
var d = reader.ReadByte();
data |= d << (i * 8);
}
var type = (ItemType)(header >> 2 & 0b11);
// TODO: do we need to handle long items?
switch (type)
{
case ItemType.Main:
var itemType = (MainItems)(header >> 4);
switch (itemType)
{
case MainItems.Input:
collection.Add(new InputReport(data, descriptor));
break;
case MainItems.Output:
collection.Add(new OutputReport(data, descriptor));
break;
case MainItems.Feature:
collection.Add(new FeatureReport(data, descriptor));
break;
case MainItems.Collection:
collection = new ReportCollection(data, descriptor.UsagePage ?? 0, descriptor.Usage ?? 0, collection);
break;
case MainItems.EndCollection:
if (collection.Parent == null)
{
// we have reached the end of a top-level collection
if (collection.Type != CollectionType.Application)
{
throw new InvalidDataException("Top-level collection must be Application");
}
yield return(collection);
}
collection = collection.Parent;
break;
}
descriptor.ClearLocals();
break;
case ItemType.Global:
case ItemType.Local:
switch (descriptor.Update(header, data))
{
// TODO: need to accumulate Usage as array
case nameof(ReportDescriptorData.Push):
descriptorStack.Push(descriptor.Copy());
break;
case nameof(ReportDescriptorData.Pop):
descriptor = descriptorStack.Pop();
break;
}
break;
default:
throw new NotSupportedException();
}
}
}
}
internal Report(ReportDescriptorData descriptor)
{
this.descriptor = descriptor?.Copy() ?? throw new ArgumentNullException(nameof(descriptor));
}
