import java.awt.*;
import java.lang.*;
import java.util.*;
import java.io.*;
import corejava.*;
import java.net.*;
import java.applet.*;


// This class responsible for all the computation, am modulation, and sound control  //
public class Signal
{
    static final double PI = Math.PI;
    double dx = (2.0*PI)/400.0;
    int Twidth = 0;
    int LENGTH = 400;


// returns  : a + b//
    Graph add( Graph a, Graph b)
    {
        Graph g = new Graph();
        double len = a.numPoints();
         for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i], a.ypoints[i] + b.ypoints[i]);}
        return g;

    }

// returns : a + constant //
    Graph add( Graph a, double constant)
    {
        Graph g = new Graph();
        double len = a.numPoints();
         for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i],a.ypoints[i] + constant); }
        return g;
    }

// returns    a - b //
    Graph minus( Graph a, Graph b)
    {
        Graph g = new Graph();
        double len = a.numPoints();
         for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i], a.ypoints[i] - b.ypoints[i]);}
        return g;

    }

// returns    a * constant //
    Graph minus( Graph a, double constant)
    {
        Graph g = new Graph();
        double len = a.numPoints();
        for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i],a.ypoints[i] - constant); }
        return g;
    }

// returns  a * b  //
    Graph mul( Graph a, Graph b)
    {
        Graph g = new Graph();
        double len = a.numPoints();
        for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i], a.ypoints[i] * b.ypoints[i]);}
        return g;

    }

// returns  a * constant //
    Graph mul( Graph a, double constant)
    {
        Graph g = new Graph();
        double len = a.numPoints();
        for (int i=0; i<len; i++)
        {    g.addPoint(a.xpoints[i],a.ypoints[i] * constant); }
        return g;
    }

// returns  a/b //
// a = numerator,  b = denominator //
    Graph div( Graph a, Graph b)
    {
        Graph g = new Graph();
        double len = a.numPoints();
        double tmp=0.0;
        for (int i=0; i<len; i++)
        {   tmp = a.ypoints[i]/b.ypoints[i];
            g.addPoint(a.xpoints[i], tmp );
            //System.out.println("div--- "+tmp);
        }
        System.out.println("done div");
        return g;

    }

// returns a /constant //
// a = numerator, constant = denominator //
    Graph div( Graph a, double constant)
    {
        Graph g = new Graph();
        double len = a.numPoints();

        for (int i=0; i<len; i++)
        {
              if (a.ypoints[i]/constant==Double.POSITIVE_INFINITY)
              System.out.println("a.ypoints/constant =" + a.ypoints[i]/constant);
              g.addPoint(a.xpoints[i],a.ypoints[i] / constant);
        }
        return g;
    }

// returns a constant  = num //
    Graph is_constant(double num)
    {
        Graph g = new Graph();
        double len = LENGTH;
       for (int i=0; i<len; i++)
        {   g.addPoint(i,num);  }
        return g;
    }

// returns   a ^ coef  //
// coef = power coefficient //
    Graph power(Graph a, int coef)
    {
        Graph g = new Graph();
        double len = a.numPoints();
        for (int i=0; i<len; i++)
        {   g.addPoint(i, Math.pow(a.Y(i), (double)(coef) ) );  }
        return g;
    }


// returns a lowpass filter //
// A= amplitude, T = bandwidth//
    Graph makelowpass( double A, double T )
    {
        Twidth = (int) (1.0/T*400.0);
        Graph g = new Graph();
        for(int i=0; i<Twidth; i++)  g.addPoint(i*dx,A);
        System.out.println("Done Make LowPass Filter");
        return g;
    }

// returns a bandpass filter //
// A= amplitude, T=bandwidth, freq = frequency //
    Graph makebandpass( double A, double T, double freq )
    {
        Twidth = (int) (1.0/T*400.0);
        Graph g = new Graph();
        Graph cos = new Graph();
        Input info = new Input();
        info.amp = 1.0;
        info.freq = freq;
        info.waveform = "Cosine";

        plotSine(info,cos, (double)(PI/2.0) );

        for(int i=0; i<Twidth; i++)  g.addPoint(i*dx,A);
        g = mul(g,cos);
        System.out.println("Done Make BandPass Filter");
        return g;
    }


// this function modify the data to sound samples.  It traps the undefined value, and any illegal values that //is not allowed in au-format  //
//  sample = sound sample buffer, and in = graph data  //

    void fitAU( byte [] sample, Graph in)
    {
          double avg = in.avg();
          double tmp = 0.0;
          double ratio =0.0;
          int count=0;
          double factor1 =1.0;
          double factor2 = 0.0;

          double yminimum=Double.POSITIVE_INFINITY;
          double ymaximum=Double.NEGATIVE_INFINITY;



          if (in.ymin() < 0.0) factor2 = Math.abs(in.ymin());


          if (in.ymax()+factor2 > 60.0 )
          {      //System.out.println("Sound is over saturated");
                 factor1 = 60.0/(in.ymax()+factor2);
          }


          int j=0;
          int once = 1;
          double max = in.numPoints();

      //    System.out.println("in.avg="+avg+"Max="+(in.ymax()+factor2)+
      //                        "Min="+(in.ymin()+tmp));

          for( int i=0; i < 400; i++)
          {

              sample[i] = (byte)( (in.Y(i)+ factor2)*factor1 );
              if ( sample[i] < 0)
              {      System.out.println("AU is below zero");
                     sample[i]=(byte)0;
              }
              else if (sample[i] >= Double.POSITIVE_INFINITY)
                  sample[i] = (byte)0;
              else if (sample[i] <= Double.NEGATIVE_INFINITY)
                  sample[i] = (byte)0;

          }
    }

// am decoding of the Transmitted signal x and the filter.  //
// returns z = recovered signal  //
// x = transmitted signal, info = specification of the filter //
    Graph decode( Graph x, Input info)
    {
          Graph z= new Graph();
          Graph filter = new Graph();

          z = x.abs(); filter = makelowpass(info.amp, info.bandwidth);
          z = convolute(z,filter);
          z = z.divide(Twidth/2.0);
          z = z.setsize(0,x.numPoints());

          System.out.println("Twidth="+Twidth);
          System.out.println("Done Detection");
          return z;
    }

//  bandpass filtering.  //
// returns the filtered component //
// a = function being filtered,  fil = specification of the filter //
    Graph filter(Graph a, Input fil )
    {
          Graph g = new Graph();
          Graph f = new Graph();
          if ( fil.waveform.equals("BandPass") )
                f = makebandpass(fil.amp,fil.bandwidth,fil.freq);
          else f = makelowpass(fil.amp,fil.bandwidth);
          g = convolute(a, f);
          g = g.setsize(0,a.numPoints());
          return g;
    }

// convolution of transmitted signal and the lowpass filter //
// x = transmitted signal, filter  = filter.  //
// returns  convolution of x and  filter//
    Graph convolute(Graph x, Graph filter)
    {
           double flen= filter.numPoints();
           double xlen = x.numPoints();
           Graph g = new Graph();
           double [] temp = new double[(int)(flen+xlen)];

               // convolution with filter //

           for ( int i=0; i<flen; i++)
           {     for ( int j=0; j < xlen ; j++)
                     temp[i+j] += filter.ypoints[i]*x.ypoints[j];
           }

           for ( int i=0; i<flen+xlen-1; i++)
           {    g.addPoint(x.xpoints[1]*i, temp[i]); }

           System.out.println("Done Convolution");

           return g;
    }



// returns a transmitted signal //
//  am encoding.  variable c specifies the carrier, and variable m the message //
    Graph encode( Graph c, Graph  m)
    {
            Graph x = new Graph();
            double value = 0.0;

            double tmp=0.0;

// make it a 100% modulation //
            if (m.ymin() < 0.0)  tmp = Math.abs(m.ymin());
// multiple message and carrier  //
            for ( int i=0; i< c.numPoints(); i++)
            {   value = c.Y(i) * ( m.Y(i)+tmp);
                x.addPoint(c.X(i), value);
            }
            System.out.println("Done Modulate");
            return x;
    }


	// returns a new functio; variable newinfo contains the specifications of the new function //

    Graph getMessage( Input newinfo )
    {
            Input info = newinfo;
            Graph g = new Graph();

            //debug info//
            info.println();System.out.println("OKOK  ---  PI = "+PI);

            if (info.waveform.equals("Sine"))
            {
                    g = new Graph();
                    plotSine(info,g, 0.0);
                    System.out.println("Getting a SineWave!");
            }

            else  if (info.waveform.equals("Cosine"))
            {
                    g = new Graph();
                    plotSine(info,g, (double)(PI/2.0) );
                    System.out.println("Getting a CosineWave!");
            }
            else if (info.waveform.equals("Triangular"))
            {
                    g = new Graph();
                    plotTriangular(info,g);
                    System.out.println("Getting a Triangular Wave!");
            }
            else if (info.waveform.equals("Square"))
            {
                    g = new Graph();
                    plotSquare(info,g);
                    System.out.println("Getting a Square Wave!");
            }
             else if (info.waveform.equals("Constant"))
            {

                    g=is_constant(info.amp);
                    System.out.println("Getting a constant!");
            }

            g = power(g,(int)info.power);
            return g;

    }


                 //generate a sine wave  //

    void plotSine(Input newinfo, Graph new_g, double phase)
    {
        double tmp=0.0;
        Graph g = new_g;
        Input info = newinfo;
        double w=0.0;
        double f = info.freq;
        info.println();

        for (int i=1; i<= 400; i++)
        {
            w=i*dx*f;

            tmp = info.amp*(Math.sin(w+phase));
            //System.out.println("tmp=" + tmp);

            if ( Math.abs(tmp) < 0.001 ) tmp =0.0;
            g.addPoint(i*dx,tmp );
        }
        System.out.println("Done Plot Sinusoidal");
    }



    //generate a triangular wave: triangle is sum of the sinusoidals //

    void plotTriangular(Input newinfo, Graph new_g)
    {
        Input info = newinfo;
        double tmp =0.0;
        Graph g = new_g;
        info.println();

        for (int i=1; i<= 400; i++)
        {
             for (double n=1.0; n<100.0; n+=2.0)
             { tmp+=(8.0*(info.amp)/(PI * PI))*(1.0/(n*n))*Math.sin(n*PI/2.0)
                        *Math.sin(n*(info.freq) *i* dx);
             }
             g.addPoint(i*dx,tmp);
             tmp=0.0;
        }

    }

       //generate a Square wave : square wave is also a sum of sinusoidals //

    void plotSquare(Input newinfo, Graph new_g)
    {   double tmp=0.0;
        Input info = newinfo;
        Graph g = new_g;

        for (int i=1; i<= 400; i++)
        {
             for (double n=1.0; n<100.0; n+=2.0)
             { tmp+=(4.0*(info.amp)/PI)*(1.0/n)*Math.sin(n*i*dx*info.freq);}
             g.addPoint(i*dx,tmp);
             tmp=0.0;
        }

    }


}