/// <summary>
/// Executes a given constructor (identified by <paramref name="constructorSelector"/>) by reading values out of the picker
/// (or prompting the user if <paramref name="pickerArgsIfAny"/> is null)
/// </summary>
/// <param name="toConstruct">The Type you want to construct</param>
/// <param name="constructorSelector">Selects which constructor on <paramref name="toConstruct"/> you want to invoke</param>
/// <param name="pickerArgsIfAny"></param>
/// <returns></returns>
protected object Construct(Type toConstruct, Func <ObjectConstructor, ConstructorInfo> constructorSelector,
IEnumerable <CommandLineObjectPickerArgumentValue> pickerArgsIfAny = null)
{
var objectConstructor = new ObjectConstructor();
var invoker = new CommandInvoker(BasicActivator);
var constructor = constructorSelector(objectConstructor);
List <object> constructorValues = new List <object>();
var pickerEnumerator = pickerArgsIfAny?.GetEnumerator();
foreach (var parameterInfo in constructor.GetParameters())
{
var required = new RequiredArgument(parameterInfo);
var parameterDelegate = invoker.GetDelegate(required);
if (parameterDelegate.IsAuto)
{
constructorValues.Add(parameterDelegate.Run(required));
}
else
{
//it's not auto
if (pickerEnumerator != null)
{
pickerEnumerator.MoveNext();
if (pickerEnumerator.Current == null)
{
throw new ArgumentException($"Value needed for parameter '{required.Name}' (of type '{required.Type}')");
}
//construct with the picker arguments
if (!pickerEnumerator.Current.HasValueOfType(required.Type))
{
throw new NotSupportedException($"Argument '{pickerEnumerator.Current.RawValue}' could not be converted to required Type '{required.Type}' for argument {required.Name}");
}
//it is a valid object yay!
constructorValues.Add(pickerEnumerator.Current.GetValueForParameterOfType(required.Type));
}
else
{
//construct by prompting user for the values
constructorValues.Add(invoker.GetValueForParameterOfType(parameterInfo));
}
}
}
pickerEnumerator?.Dispose();
return(constructor.Invoke(constructorValues.ToArray()));
}
public CommandInvokerDelegate GetDelegate(RequiredArgument required)
{
var match = _argumentDelegates.FirstOrDefault(k => k.CanHandle(required.Type));
if (match != null)
{
return(match);
}
if (required.HasDefaultValue && required.DefaultValue != null)
{
return(new CommandInvokerFixedValueDelegate(required.DefaultValue));
}
return(null);
}
private object GetValueFor(RequiredArgument a)
{
return(GetDelegate(a)?.Run(a));
}
private T SelectOne <T>(RequiredArgument parameterInfo)
{
return((T)_basicActivator.SelectOne(parameterInfo.Name, _basicActivator.GetAll <T>().Cast <IMapsDirectlyToDatabaseTable>().ToArray()));
}
private void ExecuteCommand(ConstructorInfo constructorInfo, CommandLineObjectPicker picker)
{
List <object> parameterValues = new List <object>();
bool complainAboutExtraParameters = true;
int idx = 0;
//for each parameter on the constructor we want to invoke
foreach (var parameterInfo in constructorInfo.GetParameters())
{
var required = new RequiredArgument(parameterInfo);
var argDelegate = GetDelegate(required);
//if it is an easy one to automatically fill e.g. IBasicActivateItems
if (argDelegate != null && argDelegate.IsAuto)
{
parameterValues.Add(argDelegate.Run(required));
}
else
//if the constructor argument is a picker, use the one passed in
if (parameterInfo.ParameterType == typeof(CommandLineObjectPicker))
{
if (picker == null)
{
throw new ArgumentException($"Type {constructorInfo.DeclaringType} contained a constructor which took an {parameterInfo.ParameterType} but no picker was passed");
}
parameterValues.Add(picker);
//the parameters are expected to be consumed by the target constructors so it's not really a problem if there are extra
complainAboutExtraParameters = false;
continue;
}
else
//if we have argument values specified
if (picker != null)
{
//and the specified value matches the expected parameter type
if (picker.HasArgumentOfType(idx, parameterInfo.ParameterType))
{
//consume a value
parameterValues.Add(picker[idx].GetValueForParameterOfType(parameterInfo.ParameterType));
idx++;
continue;
}
throw new Exception($"Expected parameter at index {idx} to be a {parameterInfo.ParameterType} (for parameter '{parameterInfo.Name}') but it was {(idx >= picker.Length ? "Missing":picker[idx].RawValue)}");
}
else
{
parameterValues.Add(GetValueForParameterOfType(parameterInfo));
}
}
if (picker != null && idx < picker.Length && complainAboutExtraParameters)
{
throw new Exception("Unrecognised extra parameter " + picker[idx].RawValue);
}
var instance = (IAtomicCommand)constructorInfo.Invoke(parameterValues.ToArray());
if (instance.IsImpossible)
{
CommandImpossible?.Invoke(this, new CommandEventArgs(instance));
return;
}
instance.Execute();
CommandCompleted?.Invoke(this, new CommandEventArgs(instance));
}
private T[] SelectMany <T>(RequiredArgument parameterInfo)
{
return
(_basicActivator.SelectMany(parameterInfo.Name, typeof(T), _basicActivator.GetAll <T>().Cast <IMapsDirectlyToDatabaseTable>().ToArray())
.Cast <T>().ToArray());
}
public object GetValueForParameterOfType(RequiredArgument a)
{
return(GetDelegate(a)?.Run(a));
}
private string GetPromptFor(RequiredArgument p)
{
return($"Value needed for {p.Name} ({p.Type.Name})");
}
private IPipeline SelectPipeline(RequiredArgument arg)
{
return((IPipeline)_basicActivator.SelectOne(GetPromptFor(arg), _basicActivator.RepositoryLocator.CatalogueRepository.GetAllObjects <Pipeline>().ToArray()));
}