// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Net.Sockets;
 
namespace System.Net
{
    /// <summary>
    /// Provides an IP address.
    /// </summary>
    public class IPEndPoint : EndPoint
    {
        /// <summary>
        /// Specifies the minimum acceptable value for the <see cref='System.Net.IPEndPoint.Port'/> property.
        /// </summary>
        public const int MinPort = 0x00000000;
 
        /// <summary>
        /// Specifies the maximum acceptable value for the <see cref='System.Net.IPEndPoint.Port'/> property.
        /// </summary>
        public const int MaxPort = 0x0000FFFF;
 
        private IPAddress _address;
        private int _port;
 
        public override AddressFamily AddressFamily => _address.AddressFamily;
 
        /// <summary>
        /// Creates a new instance of the IPEndPoint class with the specified address and port.
        /// </summary>
        public IPEndPoint(long address, int port)
        {
            if (!TcpValidationHelpers.ValidatePortNumber(port))
            {
                throw new ArgumentOutOfRangeException(nameof(port));
            }
 
            _port = port;
            _address = new IPAddress(address);
        }
 
        /// <summary>
        /// Creates a new instance of the IPEndPoint class with the specified address and port.
        /// </summary>
        public IPEndPoint(IPAddress address, int port)
        {
            ArgumentNullException.ThrowIfNull(address);
 
            if (!TcpValidationHelpers.ValidatePortNumber(port))
            {
                throw new ArgumentOutOfRangeException(nameof(port));
            }
 
            _port = port;
            _address = address;
        }
 
        /// <summary>
        /// Gets or sets the IP address.
        /// </summary>
        public IPAddress Address
        {
            get => _address;
            set
            {
                ArgumentNullException.ThrowIfNull(value);
                _address = value;
            }
        }
 
        /// <summary>
        /// Gets or sets the port.
        /// </summary>
        public int Port
        {
            get => _port;
            set
            {
                if (!TcpValidationHelpers.ValidatePortNumber(value))
                {
                    throw new ArgumentOutOfRangeException(nameof(value));
                }
 
                _port = value;
            }
        }
 
        public static bool TryParse(string s, [NotNullWhen(true)] out IPEndPoint? result)
        {
            return TryParse(s.AsSpan(), out result);
        }
 
        public static bool TryParse(ReadOnlySpan<char> s, [NotNullWhen(true)] out IPEndPoint? result)
        {
            int addressLength = s.Length;  // If there's no port then send the entire string to the address parser
            int lastColonPos = s.LastIndexOf(':');
 
            // Look to see if this is an IPv6 address with a port.
            if (lastColonPos > 0)
            {
                if (s[lastColonPos - 1] == ']')
                {
                    addressLength = lastColonPos;
                }
                // Look to see if this is IPv4 with a port (IPv6 will have another colon)
                else if (s.Slice(0, lastColonPos).LastIndexOf(':') == -1)
                {
                    addressLength = lastColonPos;
                }
            }
 
            if (IPAddress.TryParse(s.Slice(0, addressLength), out IPAddress? address))
            {
                uint port = 0;
                if (addressLength == s.Length ||
                    (uint.TryParse(s.Slice(addressLength + 1), NumberStyles.None, CultureInfo.InvariantCulture, out port) && port <= MaxPort))
 
                {
                    result = new IPEndPoint(address, (int)port);
                    return true;
                }
            }
 
            result = null;
            return false;
        }
 
        public static IPEndPoint Parse(string s)
        {
            ArgumentNullException.ThrowIfNull(s);
 
            return Parse(s.AsSpan());
        }
 
        public static IPEndPoint Parse(ReadOnlySpan<char> s)
        {
            if (TryParse(s, out IPEndPoint? result))
            {
                return result;
            }
 
            throw new FormatException(SR.bad_endpoint_string);
        }
 
        public override string ToString() =>
            _address.AddressFamily == AddressFamily.InterNetworkV6 ?
                string.Create(NumberFormatInfo.InvariantInfo, $"[{_address}]:{_port}") :
                string.Create(NumberFormatInfo.InvariantInfo, $"{_address}:{_port}");
 
        public override SocketAddress Serialize() => new SocketAddress(Address, Port);
 
        public override EndPoint Create(SocketAddress socketAddress)
        {
            ArgumentNullException.ThrowIfNull(socketAddress);
 
            if (socketAddress.Family is not (AddressFamily.InterNetwork or AddressFamily.InterNetworkV6))
            {
                throw new ArgumentException(SR.Format(SR.net_InvalidAddressFamily, socketAddress.Family.ToString(), GetType().FullName), nameof(socketAddress));
            }
 
            int minSize = AddressFamily == AddressFamily.InterNetworkV6 ? SocketAddress.IPv6AddressSize : SocketAddress.IPv4AddressSize;
            if (socketAddress.Size < minSize)
            {
                throw new ArgumentException(SR.Format(SR.net_InvalidSocketAddressSize, socketAddress.GetType().FullName, GetType().FullName), nameof(socketAddress));
            }
 
            return socketAddress.GetIPEndPoint();
        }
 
        public override bool Equals([NotNullWhen(true)] object? comparand)
        {
            return comparand is IPEndPoint other && other._address.Equals(_address) && other._port == _port;
        }
 
        public override int GetHashCode()
        {
            return _address.GetHashCode() ^ _port;
        }
    }
}