public ISubtractableTag SubtractTag(ISubtractableTag tag)
{
if (tag == null)
{
throw new ArgumentNullException(nameof(tag));
}
IntValueTag that = tag as IntValueTag;
if (that == null)
{
throw new InvalidRulesException($"Tried to subtract tags of different types '{RenderForLog()}' and '{tag.RenderForLog()}'.");
}
return(new IntValueTag(Key, Value - that.Value, Duration));
}
public override void AddTag(TagBase tag)
{
if (!(tag is ISubtractableTag))
{
throw new InvalidRulesException($"Tried to sum non-subtractable tag '{tag.RenderForLog()}' on '{Owner.RenderForLog()}'.");
}
ISubtractableTag newTag = null;
foreach (ISubtractableTag that in Tags.Append(tag).Where(x => x.Key == tag.Key).OfType <ISubtractableTag>())
{
newTag = newTag == null ? that : newTag.SubtractTag(that);
}
Tags.RemoveAll(x => x.Key == tag.Key);
Tags.Add((TagBase)newTag);
}
