using System;

using System.Collections.Generic;

using CSCore.DSP;

namespace Visualization

{

    /// <summary>

    ///     BasicSpectrumProvider

    /// </summary>

    public class BasicSpectrumProvider : FftProvider, ISpectrumProvider

    {

        private readonly int _sampleRate;

        private readonly List<object> _contexts = new List<object>();

        public BasicSpectrumProvider(int channels, int sampleRate, FftSize fftSize)

            : base(channels, fftSize)

        {

            if (sampleRate <= 0)

                throw new ArgumentOutOfRangeException("sampleRate");

            _sampleRate = sampleRate;

        }

        public int GetFftBandIndex(float frequency)

        {

            int fftSize = (int)FftSize;

            double f = _sampleRate / 2.0;

            // ReSharper disable once PossibleLossOfFraction

            return (int)((frequency / f) * (fftSize / 2));

        }

        public bool GetFftData(float[] fftResultBuffer, object context)

        {

            if (_contexts.Contains(context))

                return false;

            _contexts.Add(context);

            GetFftData(fftResultBuffer);

            return true;

        }

        public override void Add(float[] samples, int count)

        {

            base.Add(samples, count);

            if (count > 0)

                _contexts.Clear();

        }

        public override void Add(float left, float right)

        {

            base.Add(left, right);

            _contexts.Clear();

        }

    }

}