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

// ReSharper disable AssignNullToNotNullAttribute

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

namespace SpaceWizards.HttpListener
{
    internal sealed class ListenerPrefixEnumerator : IEnumerator<string>
    {
        private readonly IEnumerator _enumerator;

        internal ListenerPrefixEnumerator(IEnumerator enumerator)
        {
            _enumerator = enumerator;
        }

        public string Current => (string)_enumerator.Current;

        public bool MoveNext() => _enumerator.MoveNext();

        public void Dispose() { }

        void IEnumerator.Reset() => _enumerator.Reset();

        object IEnumerator.Current => _enumerator.Current;
    }

    public class HttpListenerPrefixCollection : ICollection<string>
    {
        private readonly HttpListener _httpListener;

        internal HttpListenerPrefixCollection(HttpListener listener)
        {
            _httpListener = listener;
        }

        public void CopyTo(Array array, int offset)
        {
            _httpListener.CheckDisposed();
            if (array == null)
            {
                throw new ArgumentNullException(nameof(array));
            }
            if (Count > array.Length)
            {
                throw new ArgumentOutOfRangeException(nameof(array), SR.net_array_too_small);
            }
            if (offset + Count > array.Length)
            {
                throw new ArgumentOutOfRangeException(nameof(offset));
            }
            int index = 0;
            foreach (string uriPrefix in _httpListener.PrefixCollection)
            {
                array.SetValue(uriPrefix, offset + index++);
            }
        }

        public void CopyTo(string[] array, int offset)
        {
            _httpListener.CheckDisposed();
            if (array == null)
            {
                throw new ArgumentNullException(nameof(array));
            }
            if (Count > array.Length)
            {
                throw new ArgumentOutOfRangeException(nameof(array), SR.net_array_too_small);
            }
            if (offset + Count > array.Length)
            {
                throw new ArgumentOutOfRangeException(nameof(offset));
            }
            int index = 0;
            foreach (string uriPrefix in _httpListener.PrefixCollection)
            {
                array[offset + index++] = uriPrefix;
            }
        }

        public int Count => _httpListener.PrefixCollection.Count;

        public bool IsSynchronized => false;

        public bool IsReadOnly => false;

        public void Add(string uriPrefix) => _httpListener.AddPrefix(uriPrefix);

        public bool Contains(string uriPrefix) => _httpListener.ContainsPrefix(uriPrefix);

        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

        public IEnumerator<string> GetEnumerator()
        {
            return new ListenerPrefixEnumerator(_httpListener.PrefixCollection.GetEnumerator());
        }

        public bool Remove(string uriPrefix) => _httpListener.RemovePrefix(uriPrefix);

        public void Clear() => _httpListener.RemoveAll(true);
    }
}