/*
  A test suite for dsmooth, compares dsmooth with dsmooth2

   Jon Barron, 2007
   */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <regex.h>
#include <cairo.h>
#include <math.h>

#include "cairoutils.h"
#include "dimage.h"

#define PEAKDIST 4

int is_png(const struct dirent *de) {
	regex_t preq;
	regcomp(&preq, "[^ ]*[.](png|PNG)$", REG_EXTENDED);
	return !regexec(&preq, de->d_name, (size_t) 0, NULL, 0);
}

int is_jpeg(const struct dirent *de) {
	regex_t preq;
	regcomp(&preq, "[^ ]*[.](jpg|JPG|jpeg|JPEG)$", REG_EXTENDED);
	return !regexec(&preq, de->d_name, (size_t) 0, NULL, 0);
}

int is_image(const struct dirent *de) {
	return is_jpeg(de) || is_png(de);
}

int is_output(const struct dirent *de) {
	regex_t preq;
	regcomp(&preq, "out_[^ ]*", REG_EXTENDED);
	return !regexec(&preq, de->d_name, (size_t) 0, NULL, 0);
}

int is_input_image(const struct dirent *de) {
	return is_image(de) && !is_output(de);
}

float* to_bw_f(unsigned char *image, int imW, int imH) {
	int w, h, c;
	float *image_bw;
	float v;

	image_bw = malloc(sizeof(float) * imW * imH);
	for (w = 0; w < imW; w++) {
		for (h = 0; h < imH; h++) {
			v = 0.0;
			for (c = 0; c <= 2; c++) {
				v = v + ((float)(image[4*(w*imH+h) + c])) / 3.0;
			}
			image_bw[w*imH + h] = v;
		}
	}

	return image_bw;
}

unsigned char* to_bw_u8(unsigned char *image, int imW, int imH) {
	int i;
	unsigned char *image_bw, *p;
	image_bw = p = malloc(sizeof(unsigned char) * imW * imH);
	for (i = 0; i < imW*imH; i++, image += 4, p++) {
		int total = image[0] + image[1] + image[2];
		*p = total / 3;
	}
	return image_bw;
}

unsigned char* to_cairo_bw(float *image_bw, int imW, int imH) {
	int w, h, c;
	unsigned char* image_cairo;

	image_cairo = malloc(sizeof(unsigned char) * imW * imH * 4);
	for (w = 0; w < imW; w++) {
		for (h = 0; h < imH; h++) {
			for (c = 0; c <= 2; c++) {
				image_cairo[4*(w*imH + h) + c] = (unsigned char)(image_bw[w*imH + h]);
			}
			image_cairo[4*(w*imH + h) + 3] = 255;
		}
	}

	return image_cairo;
}

int main(void) {
	struct dirent **namelist;
	int i, n, N;
	unsigned char *image = NULL;
	float *image_bw_f;
	unsigned char *image_bw_u8;
	float *image_out_old;
	float *image_out_new;
	char fullpath[255];
	char outpath_old[255];
	char outpath_new[255];
	int imW, imH;

	float sigma;
	float err;

	sigma = 1.0;

	N = scandir("demo_simplexy_images", &namelist, is_input_image, alphasort);
	if (N < 0) {
		perror("scandir");
		return 1;
	}

	for (n = 0; n < N; n++) {

		strcpy(fullpath, "demo_simplexy_images/");
		strcat(fullpath, namelist[n]->d_name);

		strcpy(outpath_old, "demo_simplexy_images/out_");
		strcat(outpath_old, namelist[n]->d_name);
		outpath_old[strlen(outpath_old)-4] = '\0';
		strcat(outpath_old, "_old");
		strcat(outpath_old, ".png");

		strcpy(outpath_new, "demo_simplexy_images/out_");
		strcat(outpath_new, namelist[n]->d_name);
		outpath_new[strlen(outpath_new)-4] = '\0';
		strcat(outpath_new, "_new");
		strcat(outpath_new, ".png");

		fprintf(stderr,"demo_dsmooth: loading %s ", fullpath);

		if (is_png(namelist[n])) {
			fprintf(stderr, "as a PNG\n");
			image = cairoutils_read_png(fullpath, &imW, &imH);
		}

		if (is_jpeg(namelist[n])) {
			fprintf(stderr, "as a JPEG\n");
			image = cairoutils_read_jpeg(fullpath, &imW, &imH);
		}

		image_bw_u8 = to_bw_u8(image, imW, imH);
		image_bw_f = malloc(sizeof(float) * imW * imH);
		for (i = 0; i < imW*imH; i++) {
			image_bw_f[i] = (float)image_bw_u8[i];
		}

		image_out_old = malloc(sizeof(float)*imW*imH);
		image_out_new = malloc(sizeof(float)*imW*imH);

		fprintf(stderr,"demo_dsmooth: running %s through dsmooth\n", fullpath);		
		dsmooth(image_bw_f, imW, imH, sigma, image_out_old);

		fprintf(stderr,"demo_dsmooth: running %s through dsmooth2\n", fullpath);
		dsmooth2(image_bw_f, imW, imH, sigma, image_out_new);
		
		err = 0.0;
		for (i = 0; i < imW*imH; i++) {
			err += fabs(image_out_old[i]-image_out_new[i]);
		}
		err = err / (imW*imH);
		
		fprintf(stderr, "demo_dsmooth: error between smooths: %f per pixel\n", err);

		//		fprintf(stderr, "demo_dsmooth: writing old dsmoothed image to %s\n", outpath_old);
		//		cairoutils_write_png(outpath_old, to_cairo_bw(image_out_old, imW, imH), imW, imH);

		//		fprintf(stderr, "demo_dsmooth: writing new dsmoothed image to %s\n", outpath_new);
		//		cairoutils_write_png(outpath_new, to_cairo_bw(image_out_new, imW, imH), imW, imH);

		free(namelist[n]);
		free(image);
		free(image_bw_f);
		free(image_bw_u8);
		free(image_out_old);
		free(image_out_new);

	}
	free(namelist);

	return 0;
}