//     _                _      _  ____   _                           _____
//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
// 
//  Copyright 2015-2018 Łukasz "JustArchi" Domeradzki
//  Contact: JustArchi@JustArchi.net
// 
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
// 
//  http://www.apache.org/licenses/LICENSE-2.0
//      
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

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

namespace ArchiSteamFarm {
	internal sealed class FixedSizeConcurrentQueue<T> : IEnumerable<T> {
		private readonly ConcurrentQueue<T> BackingQueue = new ConcurrentQueue<T>();

		internal byte MaxCount {
			get => _MaxCount;
			set {
				if (value == 0) {
					ASF.ArchiLogger.LogNullError(nameof(value));
					return;
				}

				_MaxCount = value;

				while ((BackingQueue.Count > MaxCount) && BackingQueue.TryDequeue(out _)) { }
			}
		}

		private byte _MaxCount;

		internal FixedSizeConcurrentQueue(byte maxCount) {
			if (maxCount == 0) {
				throw new ArgumentNullException(nameof(maxCount));
			}

			MaxCount = maxCount;
		}

		public IEnumerator<T> GetEnumerator() => BackingQueue.GetEnumerator();
		IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

		internal void Enqueue(T obj) {
			BackingQueue.Enqueue(obj);

			if (BackingQueue.Count <= MaxCount) {
				return;
			}

			BackingQueue.TryDequeue(out _);
		}
	}
}