using System;
using System.Diagnostics;

namespace CS4
{
    public class Throw
    {
        #region IfTrue Methods

        public static void IfTrue(bool condition, string errorMessage)
        {
            Throw.IfTrue(condition, new Exception(errorMessage));
        }

        public static void IfTrue(bool condition,
            string fmtSpec,
            params object[] args)
        {
            Debug.Assert(fmtSpec != null);
            
            string errorText = string.Format(args == null ? fmtSpec : string.Format(fmtSpec, args));
            Throw.IfTrue(condition, new Exception(errorText);
        }

        public static void IfTrue(bool condition, Exception ex)
        {
            Debug.Assert(ex != null);

            if (condition)
            {
                throw ex;
            }
        }

        #endregion

        #region IfFalse Methods

        public static void IfFalse(bool condition, string errorMessage)
        {
            Throw.IfTrue(!condition, errorMessage);
        }

        public static void IfFalse(bool condition, Exception ex)
        {
            Throw.IfTrue(!condition, ex);
        }

        public static void IfFalse(bool condition,
            string fmtSpec,
            params object[] args)
        {
            Throw.IfTrue(!condition, fmtSpec, args);
        }

        #endregion

        #region IfNull Methods

        public static void IfNull(T objRef, string errorMessage)
        {
            Throw.IfTrue(objRef == null, errorMessage);
        }

        private static void IfNull(T objRef,
        string fmtSpec,
        object[] args)
        {
            Throw.IfTrue(objRef == null, fmtSpec, args);
        }
        public static void IfNull(T objRef, Exception ex)
        {
            Throw.IfTrue(objRef == null, ex);
        }

        #endregion

        #region IfNotNull Methods

        public static void IfNotNull(T objRef, string errorMessage)
        {
            Throw.IfTrue(objRef != null, errorMessage);
        }

        public static void IfNotNull(T objRef,
              string fmtSpec,
              params object[] args)
        {
            Throw.IfTrue(objRef != null, fmtSpec, args);
        }

        public static void IfNotNull(T objRef, Exception ex)
        {
            Throw.IfTrue(objRef != null, ex);
        }

        #endregion
    }
}