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

namespace sharpcomparer
{
    public class PropertyComparison : Comparison<Property>
    {
        public string Name
        {
            get
            {
                return LeftItem != null ? LeftItem.Name : RightItem.Name;
            }
        }

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

        public PropertyComparison(Property leftItem, Property rightItem, PropertyComparison.ComparisonDifference difference)
            : base(leftItem, rightItem, difference)
        {
        }

        public static List<PropertyComparison> Compare<T>(T left, T right)
        {
            List<PropertyComparison> comparison = new List<PropertyComparison>();

            PropertyInfo[] infos = typeof(T).GetProperties();

            foreach (PropertyInfo info in infos)
            {
                object[] attributes = info.GetCustomAttributes(typeof(Hide), true);
                if (attributes.Length == 0)
                {
                    string name = info.Name;
                    string leftValue = left != null ? info.GetValue(left, null).ToString() : null;
                    string rightValue = right != null ? info.GetValue(right, null).ToString() : null;

                    Property leftProperty = left == null ? null : new Property(name, leftValue);
                    Property rightProperty = right == null ? null : new Property(name, rightValue);

                    Comparison<Property>.ComparisonDifference difference = PropertyComparison.ComparisonDifference.None;
                    if (left == null) difference = PropertyComparison.ComparisonDifference.RightOnly;
                    else if (right == null) difference = PropertyComparison.ComparisonDifference.LeftOnly;
                    else if (leftValue != rightValue) difference = PropertyComparison.ComparisonDifference.Different;

                    comparison.Add(new PropertyComparison(leftProperty, rightProperty, difference));
                }
            }

            return comparison;
        }
    }
}