// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

/*============================================================
**
**
**
** Purpose: A representation of a 32 bit 2's complement 
**          integer.
**
** 
===========================================================*/

using System;
using System.Globalization;
using System.Runtime;
using System.Runtime.InteropServices;
using System.Diagnostics.Contracts;

namespace System
{
    [Serializable]
    [System.Runtime.InteropServices.StructLayout(LayoutKind.Sequential)]
    [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
    public struct Int32 : IComparable, IFormattable, IConvertible
            , IComparable<Int32>, IEquatable<Int32>
    {
        private int m_value; // Do not rename (binary serialization)

        public const int MaxValue = 0x7fffffff;
        public const int MinValue = unchecked((int)0x80000000);

        // Compares this object to another object, returning an integer that
        // indicates the relationship. 
        // Returns a value less than zero if this  object
        // null is considered to be less than any instance.
        // If object is not of type Int32, this method throws an ArgumentException.
        // 
        public int CompareTo(Object value)
        {
            if (value == null)
            {
                return 1;
            }
            if (value is Int32)
            {
                // Need to use compare because subtraction will wrap
                // to positive for very large neg numbers, etc.
                int i = (int)value;
                if (m_value < i) return -1;
                if (m_value > i) return 1;
                return 0;
            }
            throw new ArgumentException(SR.Arg_MustBeInt32);
        }

        public int CompareTo(int value)
        {
            // Need to use compare because subtraction will wrap
            // to positive for very large neg numbers, etc.
            if (m_value < value) return -1;
            if (m_value > value) return 1;
            return 0;
        }

        public override bool Equals(Object obj)
        {
            if (!(obj is Int32))
            {
                return false;
            }
            return m_value == ((Int32)obj).m_value;
        }

        [System.Runtime.Versioning.NonVersionable]
        public bool Equals(Int32 obj)
        {
            return m_value == obj;
        }

        // The absolute value of the int contained.
        public override int GetHashCode()
        {
            return m_value;
        }

        [Pure]
        public override String ToString()
        {
            Contract.Ensures(Contract.Result<String>() != null);
            return Number.FormatInt32(m_value, null, NumberFormatInfo.CurrentInfo);
        }

        [Pure]
        public String ToString(String format)
        {
            Contract.Ensures(Contract.Result<String>() != null);
            return Number.FormatInt32(m_value, format, NumberFormatInfo.CurrentInfo);
        }

        [Pure]
        public String ToString(IFormatProvider provider)
        {
            Contract.Ensures(Contract.Result<String>() != null);
            return Number.FormatInt32(m_value, null, NumberFormatInfo.GetInstance(provider));
        }

        [Pure]
        public String ToString(String format, IFormatProvider provider)
        {
            Contract.Ensures(Contract.Result<String>() != null);
            return Number.FormatInt32(m_value, format, NumberFormatInfo.GetInstance(provider));
        }

        [Pure]
        public static int Parse(String s)
        {
            return Number.ParseInt32(s, NumberStyles.Integer, NumberFormatInfo.CurrentInfo);
        }

        [Pure]
        public static int Parse(String s, NumberStyles style)
        {
            NumberFormatInfo.ValidateParseStyleInteger(style);
            return Number.ParseInt32(s, style, NumberFormatInfo.CurrentInfo);
        }

        // Parses an integer from a String in the given style.  If
        // a NumberFormatInfo isn't specified, the current culture's 
        // NumberFormatInfo is assumed.
        // 
        [Pure]
        public static int Parse(String s, IFormatProvider provider)
        {
            return Number.ParseInt32(s, NumberStyles.Integer, NumberFormatInfo.GetInstance(provider));
        }

        // Parses an integer from a String in the given style.  If
        // a NumberFormatInfo isn't specified, the current culture's 
        // NumberFormatInfo is assumed.
        // 
        [Pure]
        public static int Parse(String s, NumberStyles style, IFormatProvider provider)
        {
            NumberFormatInfo.ValidateParseStyleInteger(style);
            return Number.ParseInt32(s, style, NumberFormatInfo.GetInstance(provider));
        }

        // Parses an integer from a String. Returns false rather
        // than throwing exceptin if input is invalid
        // 
        [Pure]
        public static bool TryParse(String s, out Int32 result)
        {
            return Number.TryParseInt32(s, NumberStyles.Integer, NumberFormatInfo.CurrentInfo, out result);
        }

        // Parses an integer from a String in the given style. Returns false rather
        // than throwing exceptin if input is invalid
        // 
        [Pure]
        public static bool TryParse(String s, NumberStyles style, IFormatProvider provider, out Int32 result)
        {
            NumberFormatInfo.ValidateParseStyleInteger(style);
            return Number.TryParseInt32(s, style, NumberFormatInfo.GetInstance(provider), out result);
        }

        //
        // IConvertible implementation
        // 

        [Pure]
        public TypeCode GetTypeCode()
        {
            return TypeCode.Int32;
        }

        bool IConvertible.ToBoolean(IFormatProvider provider)
        {
            return Convert.ToBoolean(m_value);
        }

        char IConvertible.ToChar(IFormatProvider provider)
        {
            return Convert.ToChar(m_value);
        }

        sbyte IConvertible.ToSByte(IFormatProvider provider)
        {
            return Convert.ToSByte(m_value);
        }

        byte IConvertible.ToByte(IFormatProvider provider)
        {
            return Convert.ToByte(m_value);
        }

        short IConvertible.ToInt16(IFormatProvider provider)
        {
            return Convert.ToInt16(m_value);
        }

        ushort IConvertible.ToUInt16(IFormatProvider provider)
        {
            return Convert.ToUInt16(m_value);
        }

        int IConvertible.ToInt32(IFormatProvider provider)
        {
            return m_value;
        }

        uint IConvertible.ToUInt32(IFormatProvider provider)
        {
            return Convert.ToUInt32(m_value);
        }

        long IConvertible.ToInt64(IFormatProvider provider)
        {
            return Convert.ToInt64(m_value);
        }

        ulong IConvertible.ToUInt64(IFormatProvider provider)
        {
            return Convert.ToUInt64(m_value);
        }

        float IConvertible.ToSingle(IFormatProvider provider)
        {
            return Convert.ToSingle(m_value);
        }

        double IConvertible.ToDouble(IFormatProvider provider)
        {
            return Convert.ToDouble(m_value);
        }

        Decimal IConvertible.ToDecimal(IFormatProvider provider)
        {
            return Convert.ToDecimal(m_value);
        }

        DateTime IConvertible.ToDateTime(IFormatProvider provider)
        {
            throw new InvalidCastException(SR.Format(SR.InvalidCast_FromTo, "Int32", "DateTime"));
        }

        Object IConvertible.ToType(Type type, IFormatProvider provider)
        {
            return Convert.DefaultToType((IConvertible)this, type, provider);
        }
    }
}