#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <setjmp.h>	/* for jmpbuf declaration in writepng.h */

#include "readpng.h"
#include "writepng.h"

#define ARGS "f:o:t:"
char *Usage = "rw_png -f filename\n\
-o output file\n\
-t PNM type for output (6 is 24bit, 8 is 32bit)\n";

char Fname[255];
char Oname[255];
int PNMtype;

mainprog_info Wpng_info;	/* global in Greg's code */

int main(int argc, char *argv[])
{
	int i,j;
	unsigned char *image;
	FILE *fd;
	FILE *od;
	unsigned long width;
	unsigned long height;
	unsigned long rowbytes;
	int c;
	int rc;
	int wc;
	double display_exp = 2.0;	/* check this */
	int channels;
	unsigned char *curr;
	unsigned char *new_curr;
	unsigned char red, green, blue, alpha;
	unsigned char *new_image;
	unsigned long new_rowbytes;

	PNMtype = 6;

	while((c = getopt(argc,argv,ARGS)) != EOF)
	{
		switch(c)
		{
			case 'f':
				strncpy(Fname,optarg,sizeof(Fname));
				break;
			case 'o':
				strncpy(Oname,optarg,sizeof(Oname));
				break;
			case 't':
				PNMtype = atoi(optarg);
				break;
			default:
				fprintf(stderr,"unrecognized command %c\n",
						c);
				fprintf(stderr,"%s",Usage);
				exit(1);
		}
	}

	if(Fname[0] == 0)
	{
		fprintf(stderr,"must specify file name\n");
		fprintf(stderr,"%s",Usage);
		exit(1);
	}

	fd = fopen(Fname,"rb");
	if(fd == NULL)
	{
		fprintf(stderr,"couldn't open file %s\n",Fname);
		exit(1);
	}

	if((PNMtype != 6) && (PNMtype != 8))
	{
		fprintf(stderr,"bad PNM type: %d\n",PNMtype);
		exit(1);
	}

	rc = readpng_init(fd,&width,&height);
	if(rc != 0)
	{
		fprintf(stderr,"readpng_init error %d\n",
				rc);
		exit(1);
	}

	image = readpng_get_image(display_exp, &channels, &rowbytes);

	if(image == NULL)
	{
		fprintf(stderr,"readpng_get_image fails\n");
		fclose(fd);
		readpng_cleanup(FALSE);
		exit(1);
	}

	if(Oname[0] == 0)
	{
		for(i=0; i < height; i++)
		{
			curr = &(image[i*rowbytes+0]);
			for(j=0; j < width; j++)
			{
				red = curr[0];
				green = curr[1];
				blue = curr[2];
				if(channels == 4)
				{
					alpha = curr[3];
					curr += 4;
				printf("r: %d, g: %d, b: %d, alpha: %d\n",
							red,green,blue,alpha);
				}
				else
				{
					printf("r: %d, g: %d, b: %d\n",
							red,green,blue);
					curr += 3;
				}
			}
		}

		fclose(fd);
		readpng_cleanup(FALSE);
		exit(0);
	}

	Wpng_info.infile = NULL;
	Wpng_info.outfile = NULL;
	Wpng_info.image_data = NULL;
	Wpng_info.row_pointers = NULL;
	Wpng_info.filter = FALSE;
	Wpng_info.interlaced = FALSE;
	Wpng_info.have_bg = FALSE;
	Wpng_info.have_time = FALSE;
	Wpng_info.have_text = 0;
	Wpng_info.gamma = 0.0;

	od = fopen(Oname,"wb");
	if(od == NULL)
	{
		fprintf(stderr,"couldn't output file %s\n",
				Oname);
		fclose(fd);
		readpng_cleanup(FALSE);
		exit(1);
	}

	Wpng_info.outfile = od;

	/*
	 * figure out the image match
	 */

	/*
	 * if we want a 4 channel output and we started with a 3 channel
	 * image
	 */
	if((PNMtype == 8) && (channels == 3))
	{
		printf("converting 3 channel to 4 channel\n");
		new_image = (unsigned char *)malloc(height*width*4);
		new_rowbytes = width*4;
		if(new_image == NULL)
		{
			exit(1);
		}
		memset(new_image,0,height*width*4);
		for(i=0; i < height; i++)
		{
			curr = &(image[i*rowbytes+0]);
			new_curr = &(new_image[i*new_rowbytes+0]);
			for(j=0; j < width; j++)
			{
				new_curr[0] = curr[0];
				new_curr[1] = curr[1];
				new_curr[2] = curr[2];
				new_curr[3] = 255;
				curr += 3;
				new_curr += 4;
			}
		}
		free(image);
		image = new_image;
		rowbytes = new_rowbytes;
	}
	else if((PNMtype == 6) && (channels == 4))
	{
		printf("converting 4 channel image to 3\n");
	}
	
	Wpng_info.pnmtype = PNMtype;
	Wpng_info.height = height;
	Wpng_info.width = width;
	Wpng_info.sample_depth = 8;

	wc = writepng_init(&Wpng_info);
	if(wc != 0)
	{
		fprintf(stderr,"writepng_init: error %d\n",
				wc);
		fclose(fd);
		fclose(od);
		readpng_cleanup(FALSE);
		exit(1);
	}
	Wpng_info.image_data = image;
	Wpng_info.row_pointers = (unsigned char **)malloc(height*
						sizeof(unsigned char *));
	if(Wpng_info.row_pointers == NULL)
	{
		fclose(fd);
		fclose(od);
		writepng_cleanup(&Wpng_info);
		exit(1);
	}

	for(i=0; i < height; i++)
	{
		Wpng_info.row_pointers[i] = &(image[i*rowbytes+0]);
	}


	wc = writepng_encode_image(&Wpng_info);
	if(wc != 0)
	{
		fprintf(stderr,"writepng_encode_image error %d\n",
				wc);
		fclose(fd);
		fclose(od);
		writepng_cleanup(&Wpng_info);
		exit(1);
	}
		

	free(Wpng_info.row_pointers);
	free(image);
	writepng_cleanup(&Wpng_info);

	exit(0);

}