using System;

namespace Be.Timvw.Framework.Domain
{
    public class Range<T> : IRange<T> where T : IComparable<T>
    {
        #region Private Fields

        private T begin;
        private T end;

        #endregion

        #region Public Constructors

        public Range(T begin, T end)
        {
            if (begin.CompareTo(end) > 0)
            {
                throw new ArgumentOutOfRangeException("Invalid Range");
            }

            this.begin = begin;
            this.end = end;
        }

        #endregion

        #region IRange<T> Members

        public T Begin
        {
            get { return this.begin; }
            set
            {
                if (value.CompareTo(this.end) > 0)
                {
                    throw new ArgumentOutOfRangeException("Invalid Range");
                }
                this.begin = value;
            }
        }

        public T End
        {
            get { return this.end; }
            set
            {
                if (value.CompareTo(this.begin) < 0)
                {
                    throw new ArgumentOutOfRangeException("Invalid Range");
                }
                this.end = value;
            }
        }

        public bool Includes(T t)
        {
            if (begin.CompareTo(t) > 0)
            {
                return false;
            }

            if (end.CompareTo(t) < 0)
            {
                return false;
            }

            return true;
        }

        public bool Includes(IRange<T> range)
        {
            return this.Includes(range.Begin) && this.Includes(range.End);
        }

        public bool Overlaps(IRange<T> range)
        {
            return range.Includes(this.begin) || range.Includes(this.end) || this.Includes(range);
        }

        #endregion

        #region IComparable<IRange<T>> Members

        public int CompareTo(IRange<T> other)
        {
            int compareResult = this.begin.CompareTo(other.Begin);
            if (compareResult != 0)
            {
                return compareResult;
            }
            else
            {
                return this.end.CompareTo(other.End);
            }
        }

        #endregion

        #region Overriden Methods

        public override string ToString()
        {
            return string.Format("{0} - {1}", this.begin, this.end);
        }

        public override bool Equals(object obj)
        {
            if (obj == null)
            {
                return false;
            }

            if (obj.GetType() != typeof(Range<T>))
            {
                return false;
            }

            Range<T> other = (Range<T>)obj;

            if (this.begin.CompareTo(other.begin) != 0)
            {
                return false;
            }

            if (this.end.CompareTo(other.end) != 0)
            {
                return false;
            }

            return true;
        }

        public override int GetHashCode()
        {
            return string.Format("{0} - {1}", this.begin, this.end).GetHashCode();
        }

        #endregion
    }
}