source: TFP-WebServer/SpaceWizards.HttpListener/src/System/Net/Managed/ListenerPrefix.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

//
// System.Net.ListenerPrefix
//
// Author:
//  Gonzalo Paniagua Javier (gonzalo@novell.com)
//  Oleg Mihailik (mihailik gmail co_m)
//
// Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

// ReSharper disable RedundantUsingDirective
// ReSharper disable NonReadonlyMemberInGetHashCode

using System;
using System.Diagnostics.CodeAnalysis;
using System.Net;

namespace SpaceWizards.HttpListener
{
    internal sealed class ListenerPrefix
    {
        private string _original;
        private string? _host;
        private ushort _port;
        private string? _path;
        private bool _secure;
        private IPAddress[]? _addresses;
        internal HttpListener? _listener;

        public ListenerPrefix(string prefix)
        {
            _original = prefix;
            Parse(prefix);
        }

        public override string ToString()
        {
            return _original;
        }

        public IPAddress[]? Addresses
        {
            get { return _addresses; }
            set { _addresses = value; }
        }
        public bool Secure
        {
            get { return _secure; }
        }

        public string? Host
        {
            get { return _host; }
        }

        public int Port
        {
            get { return _port; }
        }

        public string? Path
        {
            get { return _path; }
        }

        // Equals and GetHashCode are required to detect duplicates in HttpListenerPrefixCollection.
#if UNITY_NETFRAMEWORK
        public override bool Equals(object? o)
#else
        public override bool Equals([NotNullWhen(true)] object? o)
#endif
        {
            ListenerPrefix? other = o as ListenerPrefix;
            if (other == null)
                return false;

            return (_original == other._original);
        }

        public override int GetHashCode()
        {
            return _original.GetHashCode();
        }

        private void Parse(string uri)
        {
            ushort default_port = 80;
            if (uri.StartsWith("https://", StringComparison.Ordinal))
            {
                default_port = 443;
                _secure = true;
            }

            int length = uri.Length;
            int start_host = uri.IndexOf(':') + 3;
            if (start_host >= length)
                throw new ArgumentException(SR.net_listener_host);

            int end_host = ServiceNameStore.FindEndOfHostname(uri, start_host);
            int root;
            if (uri[end_host] == ':')
            {
                _host = uri.Substring(start_host, end_host - start_host);
                root = uri.IndexOf('/', end_host, length - end_host);
#if UNITY_NETFRAMEWORK
                string portPart = uri.Substring (end_host + 1, root - end_host - 1);
                _port = (ushort)int.Parse (portPart);
#else
                _port = (ushort)int.Parse(uri.AsSpan(end_host + 1, root - end_host - 1));
#endif
                _path = uri.Substring(root);
            }
            else
            {
                root = uri.IndexOf('/', start_host, length - start_host);
                _host = uri.Substring(start_host, root - start_host);
                _port = default_port;
                _path = uri.Substring(root);
            }
            if (_path.Length != 1)
                _path = _path.Substring(0, _path.Length - 1);
        }
    }
}