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

namespace DataCollectionSystem
{
    /// <summary>
    /// 两个通道根据RMS选择有效
    /// </summary>
    public class AutoRange
    { 

        //保存的数据深度  1,2 两个通道
        private List<double[]>[] DataStacks = new List<double[]>[2]
        {
            new List<double[]>(),
            new List<double[]>()
        };
        //
        //保存的数据RMS  1,2 两个通道
        private List<double>[] ListRMSs = new List<double>[2]
        {
            new List<double>(),
            new List<double>()
        };
        /// <summary>
        /// 判断深度
        /// </summary>
        private int deepth = 0;
        /// <summary>
        /// 判断阈值
        //0.632  3.16
        /// </summary>
        public double threashold = 0.01f;//阈值  10mV

        //通道增益
        public double[] Gains { get; private set; } = new double[2]
        {
            0.2f,
            100f
        };
        /// <summary>
        ///输出通道
        /// </summary>
       private int ChannelOutput = 1;

        /// <summary>
        /// 输入数据
        /// </summary>
        /// <param name="index"></param>
        /// <param name="voltages"></param>
        public void AddData(int index, double[] voltages)
        {
            if (index >= DataStacks.Length)
            {
                throw new Exception($"index {index} out of DataStacks range");
            }
            //移除最前列的,防止内存爆掉
            if (DataStacks[index].Count >= deepth)
            {
                DataStacks[index].RemoveAt(0);
                ListRMSs[index].RemoveAt(0);
            }
            DataStacks[index].Add(voltages);

            double rms = GetRMS(voltages,Gains[index]);
            ListRMSs[index].Add(rms);
        }




        /// <summary>
        /// 获取有效值
        /// </summary>
        /// <param name="voltages"></param>
        /// <returns></returns> 
        public static double GetRMS(double[] voltages,double Gain)
        {
            double RMS = 0;  
            RMS = GetRMS(voltages);
            return RMS;
        }

        public static double GetRMS(double[] voltages)
        {
            double RMS = 0;
            int length = voltages.Length;
            double sum = 0;
            for (int i = 0; i < length; i++)
            {
                // voltages[i] /= Gain;
                double product = voltages[i] * voltages[i];
                sum += product;
            }
            RMS = Math.Sqrt(sum / length);
            return RMS;
        }


        /// <summary>
        /// 构造切换声音深度
        /// </summary>
        /// <param name="deepth"></param>
        public AutoRange(int deepth)
        {
            DataStacks = new List<double[]>[2];
            for (int i = 0; i < 2; i++)
            {
                DataStacks[i] = new List<double[]>(); //111
            }
            this.deepth = deepth;
        }


        //0.632  3.16
        double VoltageRange = 0;

        private int GetOutputChanel()
        {
            int outchannel = this.ChannelOutput;
            if (DataStacks[0].Count >= deepth)
            {
                //0 通道衰减
                //1 通道放大
                //切换逻辑 是信号很强的时候,用衰减通道,
                //信号弱的时候 用放大通道.但是要超过深度了才允许切换 
                //ChannelOutput
                int i = 0;
                bool lstIntensity = ListRMSs[0][i] > threashold;  //第一个
                for (i = 1; i < deepth; i++)                     //后面的
                {
                    bool bIntensity = ListRMSs[0][i] > threashold;
                    if (lstIntensity != bIntensity)
                        break;
                }
                if (i >= deepth)  //3次一致
                {
                    outchannel = lstIntensity ? 0 : 1;//信号很强大于阈值,用衰减通道

                    // VoltageRange = outchannel?
                    //0.632  3.16
                }

            }



            return outchannel;
        }
        ///输出数据
        public double[] GetOutPutData()
        {
            double[] output = null;
            //根据RMS值判断用哪一个通道
            ChannelOutput = GetOutputChanel(); 
            int StackLen = DataStacks[0].Count;
            output = DataStacks[ChannelOutput][StackLen - 1]; //最后一个位置


            return output; 
        }

        /// <summary>
        /// 产生测试数据
        /// </summary>
        /// <param name="array"></param>
        /// <param name="amp"></param>
        /// <param name="gain"></param>
        /// <param name="freq"></param>
        public static  void GenArray(double[] array, double amp, double gain, int freq)
        {
            int SampleRate = array.Length;
            int period = SampleRate / freq;
            amp = amp * gain;

            for (int i = 0; i < period; i++)
            {
                array[i] = amp * Math.Sin(2 * Math.PI * ((double)i / period));
            }
            for (int i = 1; i < freq; i++)
            {
                Array.Copy(array, 0, array, period * i, period);
            }
            /*
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < SampleRate;i++)
            {
                sb.Append(array[i].ToString());
                sb.Append("\r\n");
            }
            string wav = sb.ToString();
            File.WriteAllText("wav.csv", wav);
            */
        }
    }
}