using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;

namespace sharpcomparer
{
    public class UserComparison : Comparison<User>
    {
        public short Uid
        {
            get
            {
                return LeftItem != null ? LeftItem.Uid : RightItem.Uid;
            }
        }

        public string UserName
        {
            get
            {
                return LeftItem != null ? LeftItem.UserName : RightItem.UserName;
            }
        }

        public UserComparison(User leftItem, User rightItem, Comparison<User>.ComparisonDifference difference)
            : base(leftItem, rightItem, difference)
        {
        }

        public static List<UserComparison> Compare(List<User> left, List<User> right)
        {
            List<UserComparison> comparison = new List<UserComparison>();
            foreach (User item in left)
            {
                User result = right.Find(
                    delegate(User find)
                    {
                        return find.Uid == item.Uid;
                    }
                );
                if (result != null)
                {
                    if (item != result)
                    {
                        comparison.Add(new UserComparison(item, result, ComparisonDifference.Different));
                    }
                    else
                    {
                        comparison.Add(new UserComparison(item, result, ComparisonDifference.None));
                    }
                }
                else
                {
                    comparison.Add(new UserComparison(item, null, ComparisonDifference.LeftOnly));
                }
            }
            foreach (User item in right)
            {
                User result = left.Find(
                    delegate(User find)
                    {
                        return find.Uid == item.Uid;
                    }
                );
                if (result == null)
                {
                    comparison.Add(new UserComparison(null, item, ComparisonDifference.RightOnly));
                }
            }
            return comparison;
        }
    }
}