#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <ppm.h>

#include "error.h"

void version(void)
{
	printf("ppminfo v" VERSION ", (C) 2007 by folkert@vanheusden.com\n\n");
}

void help(void)
{
	version();

	printf("-f file  ppm-file to analyse\n");
	printf("-v       be even more verbose (multiple (max 3) for more details)\n");
	printf("-V       print version and exit\n");
	printf("-h       this help\n");
}

int main(int argc, char *argv[])
{
	int cols, rows, format;
	pixval maxval = 0;
	FILE *fh = stdin;
	int verbose = 0;
	int c;
	char *file = NULL;

	while((c = getopt(argc, argv, "f:vVh")) != -1)
	{
		switch(c)
		{
			case 'f':
				file = optarg;
				break;

			case 'v':
				verbose++;
				break;

			case 'V':
				version();
				return 0;

			case 'h':
				help();
				return 0;

			default:
				help();
				return 1;
		}
	}

	if (file)
		fh = fopen(file, "rb");
	
	if (!fh)
		error_exit("Failed to open file!\n");
	
	ppm_readppminit(fh, &cols, &rows, &maxval, &format);

	printf("Resolution: %dx%d\n", cols, rows);
	printf("Maximum value: %d\n", maxval);

	if (verbose >= 1)
		printf("Format: %d\n", format);

	if (verbose >= 2)
	{
		int minr = maxval, maxr = 0;
		long int avgr = 0, stddevr = 0;
		int ming = maxval, maxg = 0;
		long int avgg = 0, stddevg = 0;
		int minb = maxval, maxb = 0;
		long int avgb = 0, stddevb = 0;
		int x, y, npixels = rows * cols;
		pixel *row = (pixel *)malloc(sizeof(pixel) * cols);

		for(y=0; y<rows; y++)
		{
			ppm_readppmrow(fh, row, cols, maxval, format);

			for(x=0; x<cols; x++)
			{
				minr = MIN(minr, row[x].r);
				ming = MIN(ming, row[x].g);
				minb = MIN(minb, row[x].b);
				maxr = MAX(maxr, row[x].r);
				maxg = MAX(maxg, row[x].g);
				maxb = MAX(maxb, row[x].b);
				avgr += row[x].r;
				avgg += row[x].g;
				avgb += row[x].b;
				stddevr += pow(row[x].r, 2);
				stddevg += pow(row[x].g, 2);
				stddevb += pow(row[x].b, 2);
			}
		}
		avgr /= npixels;
		avgg /= npixels;
		avgb /= npixels;
		stddevr = sqrt((stddevr / npixels) - pow(avgr, 2.0));
		stddevg = sqrt((stddevg / npixels) - pow(avgg, 2.0));
		stddevb = sqrt((stddevb / npixels) - pow(avgb, 2.0));

		printf("       %5s %5s %5s %5s\n", "min", "avg", "max", "stddev");
		printf("  red: %5d %5d %5d %5d\n", minr, (int)avgr, maxr, (int)stddevr);
		printf("green: %5d %5d %5d %5d\n", ming, (int)avgg, maxg, (int)stddevg);
		printf(" blue: %5d %5d %5d %5d\n", minb, (int)avgb, maxb, (int)stddevb);
	}
	fclose(fh);

	return 0;
}