GenericEqualityComparer

namespace EqualityComparer
{
    using System.Collections;
    using System.Collections.Generic;

    public class GenericEqualityComparer<T> : IEqualityComparer<T>
    {

        public static GenericEqualityComparer<T> Create()
        {
            return new GenericEqualityComparer<T>();
        }

        /// <summary>Determines whether the specified objects are equal.</summary>
        /// <returns>true if the specified objects are equal; otherwise, false.</returns>
        /// <param name="x">The first object of type <paramref name="T" /> to compare.</param>
        /// <param name="y">The second object of type <paramref name="T" /> to compare.</param>
        public bool Equals(T x, T y)
        {
            var comparer = GenericEqualityComparer.Create();

            return comparer.Equals(x,y);
           
        }

        /// <summary>Returns a hash code for the specified object.</summary>
        /// <returns>A hash code for the specified object.</returns>
        /// <param name="obj">The <see cref="T:System.Object" /> for which a hash code is to be returned.</param>
        /// <exception cref="T:System.ArgumentNullException">The type of <paramref name="obj" /> is a reference type and <paramref name="obj" /> is null.</exception>
        public int GetHashCode(T obj)
        {
            return 0;
        }

    }

    public class GenericEqualityComparer : IEqualityComparer
    {

        public static GenericEqualityComparer Create()
        {
            return new GenericEqualityComparer();
        }

        /// <summary>Determines whether the specified objects are equal.</summary>
        /// <returns>true if the specified objects are equal; otherwise, false.</returns>
        /// <param name="x">The first object to compare.</param>
        /// <param name="y">The second object to compare.</param>
        /// <exception cref="T:System.ArgumentException">
        /// <paramref name="x" /> and <paramref name="y" /> are of different types and neither one can handle comparisons with the other.</exception>
        public bool Equals(object x, object y)
        {
            var xProperties = x.GetType().GetProperties();

            foreach (var xProperty in xProperties)
            {
                var yProperty = y.GetType().GetProperty(xProperty.Name);

                if (yProperty == null)
                {
                    return false;
                }

                var xPropertyValue = xProperty.GetValue(x, null);

                var yPropertyValue = yProperty.GetValue(y, null);

                if (xPropertyValue == null && yPropertyValue == null)
                {
                    continue;
                }

                if (xPropertyValue == null || yPropertyValue == null)
                {
                    return false;
                }

                if (!xPropertyValue.Equals(yPropertyValue))
                {
                    return false;
                }

            }


            var xFields = x.GetType().GetFields();

            foreach (var xfield in xFields)
            {
                var yField = y.GetType().GetField(xfield.Name);

                if (yField == null)
                {
                    return false;
                }

                var xFieldValue = xfield.GetValue(x);

                var yFieldValue = yField.GetValue(y);

                if (xFieldValue == null && yFieldValue == null)
                {
                    continue;
                }

                if (xFieldValue == null || yFieldValue == null)
                {
                    return false;
                }

                if (!xFieldValue.Equals(yFieldValue))
                {
                    return false;
                }           
            }

            return true;
        }

        /// <summary>Returns a hash code for the specified object.</summary>
        /// <returns>A hash code for the specified object.</returns>
        /// <param name="obj">The <see cref="T:System.Object" /> for which a hash code is to be returned.</param>
        /// <exception cref="T:System.ArgumentNullException">The type of <paramref name="obj" /> is a reference type and <paramref name="obj" /> is null.</exception>
        public int GetHashCode(object obj)
        {
            return 0;
        }

     
    }
}