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

namespace QiHe.CodeLib
{
    /// <summary>
    /// Pair
    /// </summary>
    /// <typeparam name="TLeft">The type of the left.</typeparam>
    /// <typeparam name="TRight">The type of the right.</typeparam>
    public class Pair<TLeft, TRight> : IEquatable<Pair<TLeft, TRight>>
    {
        /// <summary>
        /// 
        /// </summary>
        public TLeft Left;
        /// <summary>
        /// 
        /// </summary>
        public TRight Right;

        /// <summary>
        /// Initializes a new instance of the <see cref="Pair&lt;TLeft, TRight&gt;"/> class.
        /// </summary>
        /// <param name="left">The left.</param>
        /// <param name="right">The right.</param>
        public Pair(TLeft left, TRight right)
        {
            Left = left;
            Right = right;
        }

        /// <summary>
        /// Returns a <see cref="T:System.String"></see> that represents the current <see cref="T:System.Object"></see>.
        /// </summary>
        /// <returns>
        /// A <see cref="T:System.String"></see> that represents the current <see cref="T:System.Object"></see>.
        /// </returns>
        public override string ToString()
        {
            return string.Format("({0},{1})", Left, Right);
        }

        /// <summary>
        /// Serves as a hash function for a particular type. <see cref="M:System.Object.GetHashCode"></see> is suitable for use in hashing algorithms and data structures like a hash table.
        /// </summary>
        /// <returns>
        /// A hash code for the current <see cref="T:System.Object"></see>.
        /// </returns>
        public override int GetHashCode()
        {
            return Left.GetHashCode() + Right.GetHashCode();
        }

        /// <summary>
        /// Determines whether the specified <see cref="T:System.Object"></see> is equal to the current <see cref="T:System.Object"></see>.
        /// </summary>
        /// <param name="obj">The <see cref="T:System.Object"></see> to compare with the current <see cref="T:System.Object"></see>.</param>
        /// <returns>
        /// true if the specified <see cref="T:System.Object"></see> is equal to the current <see cref="T:System.Object"></see>; otherwise, false.
        /// </returns>
        public override bool Equals(object obj)
        {
            if (obj is Pair<TLeft, TRight>)
            {
                return this.Equals((Pair<TLeft, TRight>)obj);
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// Indicates whether the current object is equal to another object of the same type.
        /// </summary>
        /// <param name="other">An object to compare with this object.</param>
        /// <returns>
        /// true if the current object is equal to the other parameter; otherwise, false.
        /// </returns>
        public bool Equals(Pair<TLeft, TRight> other)
        {
            return this.Left.Equals(other.Left) && this.Right.Equals(other.Right);
        }

        /// <summary>
        /// Implements the operator ==.
        /// </summary>
        /// <param name="one">The one.</param>
        /// <param name="other">The other.</param>
        /// <returns>The result of the operator.</returns>
        public static bool operator ==(Pair<TLeft, TRight> one, Pair<TLeft, TRight> other)
        {
            return one.Equals(other);
        }

        /// <summary>
        /// Implements the operator !=.
        /// </summary>
        /// <param name="one">The one.</param>
        /// <param name="other">The other.</param>
        /// <returns>The result of the operator.</returns>
        public static bool operator !=(Pair<TLeft, TRight> one, Pair<TLeft, TRight> other)
        {
            return !(one == other);
        }
    }
}