/// <summary>Invokes a command on an object by matching the command to a method using reflection.</summary>
/// <typeparam name="TObject">The object type on which to search the method. This can be used to pass an interface or a base type.</typeparam>
/// <param name="executor">The object on which to invoke the method.</param>
/// <param name="argumentCollection">The command argument list.</param>
/// <returns>The value returned by the invoked method.</returns>
/// <exception cref="OvermindException">Thrown if the command could not be matched to an executor method.</exception>
public object Invoke <TObject>(TObject executor, IList <string> argumentCollection)
{
const int argumentOffset = 2; // To ignore the executor and method names from the arguments
if (argumentCollection.Count < 2)
{
throw new OvermindException("[CommandInterpreter] Invalid arguments: missing executor method name");
}
int methodArgumentCount = argumentCollection.Count - argumentOffset;
MethodInfo methodInfo = GetExecutorMethods(typeof(TObject))
.SingleOrDefault(method => method.Name.Equals(argumentCollection[1], StringComparison.InvariantCultureIgnoreCase) &&
methodArgumentCount <= method.GetParameters().Length &&
methodArgumentCount >= method.GetParameters().Count(p => p.IsOptional == false));
if (methodInfo == null)
{
throw new OvermindException("[CommandInterpreter] Invalid arguments: executor method not found");
}
IList <ParameterInfo> parameters = methodInfo.GetParameters();
object[] parameterValues = new object[parameters.Count];
for (int parameterIndex = 0; parameterIndex < methodArgumentCount; parameterIndex++)
{
object value = null;
Type parameterType = parameters[parameterIndex].ParameterType;
string argument = argumentCollection[parameterIndex + argumentOffset];
if (parameterType == typeof(byte[]))
{
value = ByteExtensions.FromHexString(argument);
}
else if (parameterType.IsEnum)
{
value = Enum.Parse(parameterType, argument, true);
}
else
{
value = Convert.ChangeType(argument, parameterType);
}
parameterValues[parameterIndex] = value;
}
for (int parameterIndex = methodArgumentCount; parameterIndex < parameters.Count; parameterIndex++)
{
parameterValues[parameterIndex] = parameters[parameterIndex].DefaultValue;
}
return(methodInfo.Invoke(executor, parameterValues));
}
