/// <summary>Updates the part's resource.</summary>
/// <param name="partNode">
/// The part's config or a persistent state. It can be a top-level node or the <c>PART</c> node.
/// </param>
/// <param name="name">The name of the resource.</param>
/// <param name="amount">The new amount or the delta.</param>
/// <param name="isAmountRelative">
/// Tells if the amount must be added to the current item's amount instead of simply replacing it.
/// </param>
/// <returns>The new amount or <c>null</c> if the resource was not found.</returns>
public double?UpdateResource(ConfigNode partNode, string name, double amount,
bool isAmountRelative = false)
{
if (partNode.HasNode("PART"))
{
partNode = partNode.GetNode("PART");
}
var node = partNode.GetNodes("RESOURCE")
.FirstOrDefault(r => r.GetValue("name") == name);
double?setAmount = null;
if (node != null)
{
setAmount = amount;
if (isAmountRelative)
{
setAmount += ConfigAccessor.GetValueByPath <double>(node, "amount") ?? 0.0;
}
ConfigAccessor.SetValueByPath(node, "amount", setAmount.Value);
}
else
{
DebugEx.Error("Cannot find resource '{0}' in config:\n{1}", name, partNode);
}
return(setAmount);
}
