private void CompareOne(Func<IComparableObject, object> getElement, string pathToContainer, IComparableObject before, IComparableObject after, List<Difference> differences, List<AttributeChange> attributeChanges,
string name)
{
var valueBefore = getElement.Invoke(before);
var valueAfter = getElement.Invoke(after);
if (valueBefore is IEnumerable<IComparableObject>)
{
differences.AddRange(CheckArray(getElement, pathToContainer, before, after));
return;
}
if (valueBefore is IComparableObject)
{
differences.AddRange(Compare(AddToPath(pathToContainer, before.IdentifyingText), valueBefore as IComparableObject, valueAfter as IComparableObject));
return;
}
foreach (var comparer in AttributeComparers.Union(new[] { new DefaultAttributeComparer() }))
if (comparer.CanHandle(valueBefore))
{
var result = comparer.Compare(name, valueBefore, valueAfter);
if (result != null)
attributeChanges.Add(result);
return;
}
throw new Exception("Not handled: " + valueBefore.GetType());
}
private IEnumerable<Difference> CheckArray(Func<IComparableObject, object> getElement, string pathToContainer, IComparableObject before, IComparableObject after)
{
var valueBefore = (IEnumerable<IComparableObject>) getElement.Invoke(before);
var arrayBefore = valueBefore.ToList();
var valueAfter = getElement.Invoke(after) as IEnumerable<IComparableObject>;
if (valueAfter == null)
throw new ArgumentException("after object signature does not match with before object: missing " + valueBefore);
var arrayAfter = valueAfter.ToList();
var deletedElements = arrayBefore.Where(x => !arrayAfter.Exists(y => x.Id == y.Id));
var addedElements = arrayAfter.Where(x => !arrayBefore.Exists(y => x.Id == y.Id));
var differences = new List<Difference>();
differences.AddRange(deletedElements.Select(x => new DeletedObject(pathToContainer, before, x)));
differences.AddRange(addedElements.Select(x => new AddedObject(pathToContainer, after, x)));
foreach (var elementBefore in arrayBefore)
{
var elementAfter = arrayAfter.FirstOrDefault(x => x.Id == elementBefore.Id);
if (elementAfter != null)
differences.AddRange(Compare(AddToPath(pathToContainer, before.IdentifyingText), elementBefore, elementAfter));
}
return differences;
}
public IEnumerable<Difference> Compare(string pathToContainer, IComparableObject before, IComparableObject after)
{
var differences = new List<Difference>();
var attributeChanges = new List<AttributeChange>();
LoopThroughFields(pathToContainer, before, after, differences, attributeChanges);
LoopThroughProperties(pathToContainer, before, after, differences, attributeChanges);
if (attributeChanges.Count > 0)
differences.Add(new ChangedObject(pathToContainer, before, attributeChanges));
return differences;
}
public Difference(IComparableObject container)
{
Container = container;
}
public AddedObject(string pathToContainer, IComparableObject container, IComparableObject addedObject)
: base(container)
{
PathToContainer = pathToContainer;
Object = addedObject;
}
public ChangedObject(string pathToContainer, IComparableObject container, IEnumerable<AttributeChange> attributeChanges)
: this(container)
{
PathToContainer = pathToContainer;
Changes = attributeChanges;
}
public ChangedObject(IComparableObject container)
: base(container)
{
}
public DeletedObject(string pathToContainer, IComparableObject container, IComparableObject deletedObject)
: base(container)
{
PathToContainer = pathToContainer;
Object = deletedObject;
}
private void LoopThroughProperties(string pathToContainer, IComparableObject before, IComparableObject after, List<Difference> differences, List<AttributeChange> attributeChanges)
{
var propertyInfos = before.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
foreach (var propertyInfo in propertyInfos)
{
PropertyInfo info = propertyInfo;
CompareOne(x => info.GetValue(x, null), pathToContainer, before, after, differences, attributeChanges, propertyInfo.Name);
}
}
private void LoopThroughFields(string pathToContainer, IComparableObject before, IComparableObject after, List<Difference> differences,
List<AttributeChange> attributeChanges)
{
var fieldInfos = before.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public);
foreach (var fieldInfo in fieldInfos)
{
FieldInfo info = fieldInfo;
CompareOne(x => info.GetValue(x), pathToContainer, before, after, differences, attributeChanges, fieldInfo.Name);
}
}
