using System;

namespace ChadSoft.Data
{
    ///<summary>
    /// Compares all properties of a class.
    ///</summary>
    public class PropertyComparisonCriteria : ICriteria
    {
        protected readonly object instance;

        public PropertyComparisonCriteria(object instance)
        {
            this.instance = instance;
        }

        ///<summary>
        /// Does obj meet the criteria?
        ///</summary>
        ///<param name="x">Object to evaluate</param>
        ///<returns>Whether or not obj meets the criteria.</returns>
        public bool IsMatch(object x)
        {
            return IsMatch(instance, x);
        }

        ///<summary>
        /// Does obj meet the criteria?
        ///</summary>
        ///<param name="x">Object to evaluate</param>
        ///<returns>Whether or not obj meets the criteria.</returns>
        public static bool IsMatch(object x, object y)
        {
            if(x == null || y == null) return false;

            var properties = x.GetType().GetProperties();
            foreach (var prop in properties)
            {
                var iVal = prop.GetValue(x, null);
                
                // Only compare properties that have a value set
                if(iVal == null) continue;
                else if(iVal is int && (int)iVal == default(int)) continue;
                else if (iVal is decimal && (decimal)iVal == default(decimal)) continue;
                else if (iVal is DateTime && (DateTime)iVal == default(DateTime)) continue;

                if (iVal != prop.GetValue(y, null))
                    return false;
            }

            return true;
        }

    }
}