using System;
using PokerTournamentManager.Framework.Exceptions;

namespace PokerTournamentManager.Framework
{
    /// <summary>
    /// Immutable class that holds currency info
    /// </summary>
    public class Money
    {

        #region Properties
        private readonly string _CurrencyCode;
        /// <summary>
        /// Gets the currency code.
        /// </summary>
        /// <value>The currency code.</value>
        public string CurrencyCode
        {
            get { return _CurrencyCode.ToUpper(); }
        }

        private readonly double _Amount;
        /// <summary>
        /// Gets the amount.
        /// </summary>
        /// <value>The amount.</value>
        public double Amount
        {
            get { return _Amount; }
        }
        #endregion

        #region Constructors
        public Money(double amount) : this(amount, CurrencyCodes.US_DOLLAR) { }
        public Money(double amount, string currencyCode)
        {
            if (String.IsNullOrEmpty(currencyCode)) throw new ArgumentNullException("currencyCode");
            if (amount < 0) throw new ArgumentOutOfRangeException("amount");

            this._Amount = amount;
            this._CurrencyCode = currencyCode;
        }
        #endregion

        #region Overrides
        /// <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)
        {
            bool equals = false;
            if (obj != null && obj is Money)
            {
                Money tmp = (obj as Money);
                equals = tmp.Amount == this.Amount && tmp.CurrencyCode == this.CurrencyCode;
            }
            
            return equals;
        }
        #endregion

        #region Operators
        /// <summary>
        /// Implements the operator +.
        /// </summary>
        /// <param name="money1">The money1.</param>
        /// <param name="money2">The money2.</param>
        /// <returns>The result of the operator.</returns>
        public static Money operator +(Money money1, Money money2)
        {
            if (money1 == null) throw new ArgumentNullException("money1");
            if (money2 == null) throw new ArgumentNullException("money2");
            if (money1.CurrencyCode != money2.CurrencyCode)
                throw new IncorrectCurrencyException();

            return new Money(money1.Amount + money2.Amount);
        }
        #endregion

        #region Inner Classes
        /// <summary>
        /// Static class serving as a Container for 
        /// supported Currency Code constants
        /// </summary>
        public static class CurrencyCodes
        {
            /// <summary>
            /// United States Dollar
            /// </summary>
            public const string US_DOLLAR   = "USD";
            public const string GB_POUND    = "GBP";
        }
        #endregion

    }
}