#include "data_func.h"

int cal_1d_v(const char* inname,const char* outname)
{
	ifstream infile(inname);
	if (!infile)
	{
		cout<<inname<<" not found, program stopped..."<<endl;
		return 1;
	}
	else
	{
		stringstream temp_xz;
		string templine;
		valuelist list_x;
		valuelist list_z;
		double temp_x,temp_z;
		int dnum,Dnum,Lnum,Rnum,half_Dnum;
		double endmean;
		double du;
		double dx;

		while(getline(infile,templine))
		{
			if (templine!="")
			{
				temp_xz.clear();
				temp_xz.str(templine);
				temp_xz>>temp_x>>temp_z;
				list_x.push_back(temp_x);
				list_z.push_back(temp_z);
			}
		}
		infile.close();

		dnum = list_x.size();
		double* array_x = new double [dnum];
		double* array_z = new double [dnum];

		double tempvalue;
		int count = 0;
		for (iv=list_x.begin();iv!=list_x.end(); ++iv)
		{
			tempvalue = *iv;
			array_x[count]=tempvalue;
			count++;
		}
		count = 0;
		for (iv=list_z.begin();iv!=list_z.end(); ++iv)
		{
			tempvalue = *iv;
			array_z[count]=tempvalue;
			count++;
		}
		dx = abs(array_x[1]-array_x[0]);

		//testing
		/*
		for (int i = 0; i < dnum; i++)
		{
			cout<<array_x[i]<<" "<<array_z[i]<<endl;
		}
		*/

		Dnum = pow(2,ceil(log(dnum)/log(2))+1);//对数据进行余弦扩边
		Lnum = floor((Dnum-dnum)/2.0);
		Rnum = ceil((Dnum-dnum)/2.0);
		double* Array_z = new double [Dnum];

		endmean = (array_z[0]+array_z[dnum-1])/2.0;//求取扩边的端点值
		for (int i = 0; i < Lnum; i++)
		{
			Array_z[i] = endmean + (array_z[0]-endmean)*cos(-0.5*pi*(i-Lnum)/Lnum);
		}
		for (int i = 0; i < dnum; i++)
		{
			Array_z[Lnum+i] = array_z[i];
		}
		for (int i = 0; i < Rnum; i++)
		{
			Array_z[Lnum+dnum+i] = endmean + (array_z[dnum-1]-endmean)*cos(0.5*pi*(i+1)/Rnum);
		}
		half_Dnum = Dnum/2;
		du = pi*2/(Dnum*dx);

		fftw_complex *in, *out, *after_out, *reout;
		fftw_plan p;
		in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * Dnum);
		out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * Dnum);
		after_out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * Dnum);
		reout = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * Dnum);

		for (int i = 0; i < Dnum; i++)
		{
			in[i][0] = Array_z[i];
			in[i][1] = 0.0;
		}

		p=fftw_plan_dft_1d(Dnum,in,out, FFTW_FORWARD, FFTW_ESTIMATE);
    	fftw_execute(p); /* repeat as needed*/

		double u;
		int k;
    	for (int i = 0; i < half_Dnum; i++)
    	{
    		u = du*i;
    		after_out[i][1] = out[i][1]*u;
    		after_out[i][0] = out[i][0]*u;
    		if (i!=0&&i!=half_Dnum)
    		{
    			k = Dnum-i;
    			after_out[k][1] = out[k][1]*u;
    			after_out[k][0] = out[k][0]*u;
    		}
    	}

    	p=fftw_plan_dft_1d(Dnum,after_out,reout, FFTW_BACKWARD, FFTW_ESTIMATE);
    	fftw_execute(p);

    	ofstream outfile(outname);
    	for (int i = 0; i < dnum; i++)
    	{
    		outfile<<array_x[i]<<" "<<1e+4*reout[i+Lnum][0]/Dnum<<endl;
    	}
    	outfile.close();

    	fftw_destroy_plan(p);
	    fftw_free(in); 
	    fftw_free(out);
	    fftw_free(after_out);
		fftw_free(reout);
		delete[] Array_z;
		delete[] array_x;
		delete[] array_z;
		return 0;
	}
}