/src/FluentNHibernate/Testing/Values/List.cs

using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using FluentNHibernate.Utils;



namespace FluentNHibernate.Testing.Values

{

    public class List<T, TListElement> : Property<T, IEnumerable<TListElement>>

    {

        private readonly IEnumerable<TListElement> _expected;

        private Action<T, Accessor, IEnumerable<TListElement>> _valueSetter;



        public List(Accessor property, IEnumerable<TListElement> value)

            : base(property, value)

        {

            _expected = value;

        }



        public override Action<T, Accessor, IEnumerable<TListElement>> ValueSetter

        {

            get

            {

                if (_valueSetter != null)

                {

                    return _valueSetter;

                }



                return (target, propertyAccessor, value) =>

                {

                    object collection;



                    // sorry guys - create an instance of the collection type because we can't rely

                    // on the user to pass in the correct collection type (especially if they're using

                    // an interface). I've tried to create the common ones, but I'm sure this won't be

                    // infallible.

                    if (propertyAccessor.PropertyType.IsAssignableFrom(typeof(ISet<TListElement>)))

                    {

                        collection = new HashSet<TListElement>(Expected.ToList());

                    }

                    else if (propertyAccessor.PropertyType.IsArray)

                    {

                        collection = Array.CreateInstance(typeof(TListElement), Expected.Count());

                        Array.Copy((Array)Expected, (Array)collection, Expected.Count());

                    }

                    else

                    {

                        collection = new List<TListElement>(Expected);

                    }



                    propertyAccessor.SetValue(target, collection);

                };

            }

            set { _valueSetter = value; }

        }



        protected IEnumerable<TListElement> Expected

        {

            get { return _expected; }

        }



        public override void CheckValue(object target)

        {

            var actual = PropertyAccessor.GetValue(target) as IEnumerable;

            AssertGenericListMatches(actual, Expected);

        }



        private void AssertGenericListMatches(IEnumerable actualEnumerable, IEnumerable<TListElement> expectedEnumerable)

        {

            if (actualEnumerable == null)

            {

                throw new ArgumentNullException("actualEnumerable",

                    "Actual and expected are not equal (actual was null).");

            }

            if (expectedEnumerable == null)

            {

                throw new ArgumentNullException("expectedEnumerable",

                    "Actual and expected are not equal (expected was null).");

            }



            List<object> actualList = new List<object>();

            foreach (var item in actualEnumerable)

            {

                actualList.Add(item);

            }



            var expectedList = expectedEnumerable.ToList();



            if (actualList.Count != expectedList.Count)

            {

                throw new ApplicationException(String.Format("Actual count ({0}) does not equal expected count ({1})", actualList.Count, expectedList.Count));

            }



            var equalsFunc = (EntityEqualityComparer != null) ? ((a, b) => EntityEqualityComparer.Equals(a, b)): new Func<object, object, bool>(Equals);



            for (var i = 0; i < actualList.Count; i++)

            {

                if (equalsFunc(actualList[i], expectedList[i]))

                {

                    continue;

                }



                var message = String.Format("Expected '{0}' but got '{1}' at position {2}",

                    expectedList[i],

                    actualList[i],

                    i);



                throw new ApplicationException(message);

            }

        }

    }

}