public static Changes <TEntity, TModel> GetChanges <TEntity, TModel>(
this ICollection <TEntity> entities,
ICollection <TModel> models,
Func <TEntity, TModel, bool> compare)
{
var result = new Changes <TEntity, TModel>();
if (entities == null)
{
return(result);
}
if (models?.Any() != true)
{
result.Deleted = entities.ToList();
return(result);
}
result.Deleted = entities
.Where(entity => models.All(model => !compare(entity, model)))
.ToList();
var updated = new Dictionary <TEntity, TModel>();
foreach (var model in models)
{
var entity = entities.SingleOrDefault(e => compare(e, model));
if (entity != null)
{
updated.Add(entity, model);
}
}
result.Updated = updated;
result.Added = models
.Where(model => entities.All(entity => !compare(entity, model)))
.ToList();
return(result);
}