using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace SipComponent
{
    class VoiceBuffer2
    {
        ByteQueue _byteQueue;
        int _maxSize;
        object _lockerOnTake = new object();
        object _lockerOnAdd = new object();
        bool _addingWasStopped;
        volatile bool _fireEventHalfFull = true;

        public VoiceBuffer2(int maxSize)
        {
            _maxSize = maxSize;
            _byteQueue = new ByteQueue();
        }

        /*
        public int TakeBytes(byte[] b)
        {
            int nbObBytesTaken = 0;
            int length = b.Length;
            lock (_lockerOnTake)
            {
                while (_byteQueue.Length < length && !_addingWasStopped)
                {
                    OnEmpty(new EventArgs());
                    Monitor.Wait(_lockerOnTake);
                }
                if (_addingWasStopped)
                    return nbObBytesTaken;
            }
            nbObBytesTaken = _byteQueue.Dequeue(b, 0, length);
            // Notify that adding can unblock
            lock (_lockerOnAdd)
                Monitor.Pulse(_lockerOnAdd);
#if DEBUG
            //Console.WriteLine(_byteQueue.Length);
#endif
            return nbObBytesTaken;
        }
        */

        public int TakeBytes(byte[] b)
        {
            int nbObBytesTaken = 0;
            int length = b.Length;
            lock (_lockerOnTake)
            {
                while (_byteQueue.Length < length && !_addingWasStopped)
                {
                    OnEmpty(new EventArgs());
                    Monitor.Wait(_lockerOnTake);
                }
                //if (_addingWasStopped)
                //    return nbObBytesTaken;
            }
            nbObBytesTaken = _byteQueue.Dequeue(b, 0, length);
            // Notify that adding can unblock
            lock (_lockerOnAdd)
                Monitor.Pulse(_lockerOnAdd);
//#if DEBUG
//            Console.WriteLine(_byteQueue.Length);
//#endif
            return nbObBytesTaken;
        }

        public void AddBytes(byte[] b)
        {
            int length = b.Length;
            lock (_lockerOnAdd)
            {
                if (_addingWasStopped)
                    throw new SipClassException("Cannot add bytes to VoiceBuffer after calling StopAdding() method!");
                while (_byteQueue.Length + length > _maxSize)
                {
                    OnFull(new EventArgs());
                    Monitor.Wait(_lockerOnAdd);
                }
            }
            _byteQueue.Enqueue(b, 0, b.Length);
            // Notify that taking thread can unblock
            lock (_lockerOnTake)
            {
                Monitor.Pulse(_lockerOnTake);
            }
            if (_fireEventHalfFull)
            {
                if (_byteQueue.Length >= _maxSize / 2)
                {
                    OnHalfFull(new EventArgs());
                    _fireEventHalfFull = false;

                }
            }
//#if DEBUG
//            Console.WriteLine(_byteQueue.Length);
//#endif
        }

        /// <summary>
        /// Notifies the taking thread that adding was stopped and must continue
        /// </summary>
        public void StopAdding()
        {
            lock (_lockerOnTake)
            {
                _addingWasStopped = true;
                Monitor.PulseAll(_lockerOnTake);
            }
        }

        #region Events

        public event EventHandler HalfFull;
        public event EventHandler Full;
        public event EventHandler Empty;
        
        
        public void OnHalfFull(EventArgs e)
        {
            EventHandler handler = HalfFull;
            if (handler != null)
                handler(this, e);
        }
        public void OnFull(EventArgs e)
        {
            EventHandler handler = Full;
            if (handler != null)
                handler(this, e);
        }
        public void OnEmpty(EventArgs e)
        {
            EventHandler handler = Empty;
            if (handler != null)
                handler(this, e);
        }

        #endregion
    }
}