#include <stdio.h>
#include "plot3d.h"

static void plot_with_geomview(struct plot3d *data)
{
	FILE *fp;
	int m = data->m;
	int n = data->n;
	double dx = (data->b - data->a) / n;
	double dt = data->T / m;

	fp = fopen(data->geomview_out, "w");

	if (fp == NULL) {
		fprintf(stderr, "*** Cannot open Geomview script file %s "
				"for writing\n", data->geomview_out);
		return;
	}

	fprintf(fp, "# Geomview script writen by Math 625's finite difference solver\n");

	fprintf(fp, "{ appearance { +edge }\n");
	fprintf(fp, "MESH %d %d\n", n+1, m+1);

	for (int i = 0; i <= m; i++) {
		double t = i*dt;
		for (int j = 0; j <= n; j++) {
			double x = data->a + j*dx;
			fprintf(fp, "%g %g %g\n", x, t, data->u[i][j]);
		}
	}

	fprintf(fp, "}\n");

	fclose(fp);

	printf("Geomview script written to %s\n", data->geomview_out);
}

static void plot_with_maple(struct plot3d *data)
{
	FILE *fp;
	int m = data->m;
	int n = data->n;
	double dx = (data->b - data->a) / n;
	double dt = data->T / m;

	fp = fopen(data->maple_out, "w");

	if (fp == NULL) {
		fprintf(stderr, "*** Cannot open Maple script file %s "
				"for writing\n", data->maple_out);
		return;
	}

	fprintf(fp, "# Maple script writen by Math 625's finite difference solver\n");

	fprintf(fp, "plots:-display(MESH([\n");

	for (int i = 0; i <= m; i++) {
		double t = i*dt;
		fprintf(fp, "\t[");
		for (int j = 0; j <= n; j++) {
			double x = data->a + j*dx;
			fprintf(fp, "[%g,%g,%g],", x, t, data->u[i][j]);
		}
		fprintf(fp, "NULL],\n");
	}
	fprintf(fp, "NULL]), labels=[x,t,u]);");

	fclose(fp);

	printf("Maple script written to %s\n", data->maple_out);
}

// names of matlab's plotting variables 
#define XVEC	"PLOT_WITH_MATLAB_FD_XVEC"
#define TVEC	"PLOT_WITH_MATLAB_FD_TVEC"
#define ZMAT	"PLOT_WITH_MATLAB_FD_ZMAT"

static void plot_with_matlab(struct plot3d *data)
{
	FILE *fp;
	int m = data->m;
	int n = data->n;
	double dx = (data->b - data->a) / n;
	double dt = data->T / m;

	fp = fopen(data->matlab_out, "w");

	if (fp == NULL) {
		fprintf(stderr, "*** Cannot open Matlab script file %s "
				"for writing\n", data->matlab_out);
		return;
	}

	fprintf(fp, "%% Matlab script writen by Math 625's finite difference solver\n");

	fprintf(fp, "%s = [\n", XVEC);
	for (int j = 0; j <= n; j++) {
		double x = data->a + j*dx;
		fprintf(fp, "%g ", x);
	}
	fprintf(fp, "\n];\n");

	fprintf(fp, "%s = [\n", TVEC);
	for (int i = 0; i <= m; i++) {
		double t = i*dt;
		fprintf(fp, "%g ", t);
	}
	fprintf(fp, "\n];\n");

	fprintf(fp, "%s = [\n", ZMAT);
	for (int i = 0; i <= m; i++) {
		for (int j = 0; j <= n; j++)
			fprintf(fp, "%g ", data->u[i][j]);
		fprintf(fp, "\n");
	}
	fprintf(fp, "];\n");

	fprintf(fp, "surf(%s, %s, %s)\n", XVEC, TVEC, ZMAT);
	fprintf(fp, "xlabel('x')\n");
	fprintf(fp, "ylabel('t')\n");
	fprintf(fp, "zlabel('u')\n");
	fprintf(fp, "colormap jet\n");

	fclose(fp);

	printf("Matlab script written to %s\n", data->matlab_out);

}

#undef XVEC
#undef TVEC
#undef ZMAT

void plot3d(struct plot3d *data)
{
	if (data->geomview_out != NULL)
		plot_with_geomview(data);

	if (data->maple_out != NULL)
		plot_with_maple(data);

	if (data->matlab_out != NULL)
		plot_with_matlab(data);
}