#ifndef __BITMAP_SAVER_H__
#define __BITMAP_SAVER_H__

#include "UnpackedBitmap.h"
#include "PNG.h"

#include <stdio.h>
#include <string.h>

#ifdef _WIN32
#include <io.h>
#include <sys/fcntl.h>
int _fileno(FILE *fh); // Why isn't this defined? Who knows.
#endif

static void StartChunk(FILE *fh,uint32_t id,uint32_t size,uint32_t *crc);
static void EndChunk(FILE *fh,uint32_t *crc);
static void WriteChunkByte(FILE *fh,uint8_t byte,uint32_t *crc);
static void WriteChunkUInt32(FILE *fh,uint32_t val,uint32_t *crc);

static void WriteDeflateByte(FILE *fh,uint8_t byte,uint32_t streamsize,uint32_t *streampos,uint32_t *adler,uint32_t *crc);

static void WriteByte(FILE *fh,uint8_t byte);
static void WriteUInt32(FILE *fh,uint32_t val);

static void SaveBitmapOrDie(const UnpackedBitmap *bitmap,const char *filename)
{
	FILE *fh;

	if(strcmp(filename,"-")==0)
	{
		fh=stdout;
		#ifdef _WIN32
		setmode(_fileno(stdout),O_BINARY);
		#endif
	}
	else
	{
		fh=fopen(filename,"wb");
		if(!fh)
		{
			fprintf(stderr,"Failed to open file \"%s\".\n",filename);
			exit(1);
		}
	}

	WriteByte(fh,137);
	WriteByte(fh,80);
	WriteByte(fh,78);
	WriteByte(fh,71);
	WriteByte(fh,13);
	WriteByte(fh,10);
	WriteByte(fh,26);
	WriteByte(fh,10);

	uint32_t crc;

	StartChunk(fh,PNGMakeID('I','H','D','R'),13,&crc);
	WriteChunkUInt32(fh,bitmap->width,&crc);
	WriteChunkUInt32(fh,bitmap->height,&crc);
	WriteChunkByte(fh,8,&crc);
	WriteChunkByte(fh,6,&crc);
	WriteChunkByte(fh,0,&crc);
	WriteChunkByte(fh,0,&crc);
	WriteChunkByte(fh,0,&crc);
	EndChunk(fh,&crc);

	uint32_t streamsize=(bitmap->width*4+1)*bitmap->height;
	uint32_t chunksize=streamsize+((streamsize-1)/65535+1)*5+6;

	StartChunk(fh,PNGMakeID('I','D','A','T'),chunksize,&crc);

	WriteChunkByte(fh,0x78,&crc);
	WriteChunkByte(fh,0x01,&crc);

	uint32_t streampos=0;
	uint32_t adler=1;

	for(int y=0;y<bitmap->height;y++)
	{
		WriteDeflateByte(fh,0x00,streamsize,&streampos,&adler,&crc);
		for(int x=0;x<bitmap->width;x++)
		{
			UnpackedPixel p=UnpackedPixelAt(bitmap,x,y);
			WriteDeflateByte(fh,p.r,streamsize,&streampos,&adler,&crc);
			WriteDeflateByte(fh,p.g,streamsize,&streampos,&adler,&crc);
			WriteDeflateByte(fh,p.b,streamsize,&streampos,&adler,&crc);
			WriteDeflateByte(fh,p.a,streamsize,&streampos,&adler,&crc);
		}
	}

	WriteChunkByte(fh,adler>>24,&crc);
	WriteChunkByte(fh,adler>>16,&crc);
	WriteChunkByte(fh,adler>>8,&crc);
	WriteChunkByte(fh,adler,&crc);

	EndChunk(fh,&crc);

	StartChunk(fh,PNGMakeID('I','E','N','D'),0,&crc);
	EndChunk(fh,&crc);

	fclose(fh);
}

static void StartChunk(FILE *fh,uint32_t id,uint32_t size,uint32_t *crc)
{
	*crc=0xffffffff;
	WriteUInt32(fh,size);
	WriteChunkUInt32(fh,id,crc);
}

static void EndChunk(FILE *fh,uint32_t *crc)
{
	WriteUInt32(fh,*crc^0xffffffff);
}

static void WriteChunkByte(FILE *fh,uint8_t byte,uint32_t *crc)
{
	WriteByte(fh,byte);

	static const uint32_t crctable[256]=
	{
		0x00000000,0x77073096,0xee0e612c,0x990951ba,0x076dc419,0x706af48f,0xe963a535,0x9e6495a3,
		0x0edb8832,0x79dcb8a4,0xe0d5e91e,0x97d2d988,0x09b64c2b,0x7eb17cbd,0xe7b82d07,0x90bf1d91,
		0x1db71064,0x6ab020f2,0xf3b97148,0x84be41de,0x1adad47d,0x6ddde4eb,0xf4d4b551,0x83d385c7,
		0x136c9856,0x646ba8c0,0xfd62f97a,0x8a65c9ec,0x14015c4f,0x63066cd9,0xfa0f3d63,0x8d080df5,
		0x3b6e20c8,0x4c69105e,0xd56041e4,0xa2677172,0x3c03e4d1,0x4b04d447,0xd20d85fd,0xa50ab56b,
		0x35b5a8fa,0x42b2986c,0xdbbbc9d6,0xacbcf940,0x32d86ce3,0x45df5c75,0xdcd60dcf,0xabd13d59,
		0x26d930ac,0x51de003a,0xc8d75180,0xbfd06116,0x21b4f4b5,0x56b3c423,0xcfba9599,0xb8bda50f,
		0x2802b89e,0x5f058808,0xc60cd9b2,0xb10be924,0x2f6f7c87,0x58684c11,0xc1611dab,0xb6662d3d,
		0x76dc4190,0x01db7106,0x98d220bc,0xefd5102a,0x71b18589,0x06b6b51f,0x9fbfe4a5,0xe8b8d433,
		0x7807c9a2,0x0f00f934,0x9609a88e,0xe10e9818,0x7f6a0dbb,0x086d3d2d,0x91646c97,0xe6635c01,
		0x6b6b51f4,0x1c6c6162,0x856530d8,0xf262004e,0x6c0695ed,0x1b01a57b,0x8208f4c1,0xf50fc457,
		0x65b0d9c6,0x12b7e950,0x8bbeb8ea,0xfcb9887c,0x62dd1ddf,0x15da2d49,0x8cd37cf3,0xfbd44c65,
		0x4db26158,0x3ab551ce,0xa3bc0074,0xd4bb30e2,0x4adfa541,0x3dd895d7,0xa4d1c46d,0xd3d6f4fb,
		0x4369e96a,0x346ed9fc,0xad678846,0xda60b8d0,0x44042d73,0x33031de5,0xaa0a4c5f,0xdd0d7cc9,
		0x5005713c,0x270241aa,0xbe0b1010,0xc90c2086,0x5768b525,0x206f85b3,0xb966d409,0xce61e49f,
		0x5edef90e,0x29d9c998,0xb0d09822,0xc7d7a8b4,0x59b33d17,0x2eb40d81,0xb7bd5c3b,0xc0ba6cad,
		0xedb88320,0x9abfb3b6,0x03b6e20c,0x74b1d29a,0xead54739,0x9dd277af,0x04db2615,0x73dc1683,
		0xe3630b12,0x94643b84,0x0d6d6a3e,0x7a6a5aa8,0xe40ecf0b,0x9309ff9d,0x0a00ae27,0x7d079eb1,
		0xf00f9344,0x8708a3d2,0x1e01f268,0x6906c2fe,0xf762575d,0x806567cb,0x196c3671,0x6e6b06e7,
		0xfed41b76,0x89d32be0,0x10da7a5a,0x67dd4acc,0xf9b9df6f,0x8ebeeff9,0x17b7be43,0x60b08ed5,
		0xd6d6a3e8,0xa1d1937e,0x38d8c2c4,0x4fdff252,0xd1bb67f1,0xa6bc5767,0x3fb506dd,0x48b2364b,
		0xd80d2bda,0xaf0a1b4c,0x36034af6,0x41047a60,0xdf60efc3,0xa867df55,0x316e8eef,0x4669be79,
		0xcb61b38c,0xbc66831a,0x256fd2a0,0x5268e236,0xcc0c7795,0xbb0b4703,0x220216b9,0x5505262f,
		0xc5ba3bbe,0xb2bd0b28,0x2bb45a92,0x5cb36a04,0xc2d7ffa7,0xb5d0cf31,0x2cd99e8b,0x5bdeae1d,
		0x9b64c2b0,0xec63f226,0x756aa39c,0x026d930a,0x9c0906a9,0xeb0e363f,0x72076785,0x05005713,
		0x95bf4a82,0xe2b87a14,0x7bb12bae,0x0cb61b38,0x92d28e9b,0xe5d5be0d,0x7cdcefb7,0x0bdbdf21,
		0x86d3d2d4,0xf1d4e242,0x68ddb3f8,0x1fda836e,0x81be16cd,0xf6b9265b,0x6fb077e1,0x18b74777,
		0x88085ae6,0xff0f6a70,0x66063bca,0x11010b5c,0x8f659eff,0xf862ae69,0x616bffd3,0x166ccf45,
		0xa00ae278,0xd70dd2ee,0x4e048354,0x3903b3c2,0xa7672661,0xd06016f7,0x4969474d,0x3e6e77db,
		0xaed16a4a,0xd9d65adc,0x40df0b66,0x37d83bf0,0xa9bcae53,0xdebb9ec5,0x47b2cf7f,0x30b5ffe9,
		0xbdbdf21c,0xcabac28a,0x53b39330,0x24b4a3a6,0xbad03605,0xcdd70693,0x54de5729,0x23d967bf,
		0xb3667a2e,0xc4614ab8,0x5d681b02,0x2a6f2b94,0xb40bbe37,0xc30c8ea1,0x5a05df1b,0x2d02ef8d,
	};

	*crc=crctable[(*crc^byte)&0xff]^(*crc>>8);
}

static void WriteChunkUInt32(FILE *fh,uint32_t val,uint32_t *crc)
{
	WriteChunkByte(fh,val>>24,crc);
	WriteChunkByte(fh,val>>16,crc);
	WriteChunkByte(fh,val>>8,crc);
	WriteChunkByte(fh,val,crc);
}

static void WriteDeflateByte(FILE *fh,uint8_t byte,uint32_t streamsize,uint32_t *streampos,uint32_t *adler,uint32_t *crc)
{
	if(*streampos%65535==0)
	{
		int blocksize;
		if(*streampos+65535<streamsize)
		{
			WriteChunkByte(fh,0x00,crc);
			blocksize=65535;
		}
		else
		{
			WriteChunkByte(fh,0x01,crc);
			blocksize=streamsize-*streampos;
		}
		WriteChunkByte(fh,blocksize,crc);
		WriteChunkByte(fh,blocksize>>8,crc);
		WriteChunkByte(fh,blocksize^0xff,crc);
		WriteChunkByte(fh,(blocksize>>8)^0xff,crc);
	}

	WriteChunkByte(fh,byte,crc);

	int s1=*adler&0xffff;
	int s2=*adler>>16;
	s1=(s1+byte)%65521;
	s2=(s2+s1)%65521;
	*adler=(s2<<16)|s1;

	(*streampos)++;
}

static void WriteByte(FILE *fh,uint8_t byte)
{
	if(fputc(byte,fh)==EOF)
	{
		fprintf(stderr,"Error while writing to disk.\n");
		exit(0);
	}
}

static void WriteUInt32(FILE *fh,uint32_t val)
{
	WriteByte(fh,val>>24);
	WriteByte(fh,val>>16);
	WriteByte(fh,val>>8);
	WriteByte(fh,val);
}

#endif