TARGET := $(lastword $(subst /, ,$(abspath $(dir $(lastword $(MAKEFILE_LIST))))))

CC = g++

all: $(TARGET)

$(TARGET): *.c
	$(CC) -O3 -Wall -fopenmp -o $(TARGET) *.c `pkg-config --cflags --libs opencv4`

clean:
	rm $(TARGET)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <iostream>

#define FITS_BLOCK_SIZE 2880
#define FITS_RECORD_SIZE 80

//ファイル名をコピーして、拡張子 raw を fts に変換します。
void RawNmae2Fts(char *Fts, char *Raw){
	strcpy(Fts, Raw);
	int len=strlen(Fts);
	strcpy(Fts+len-3,"fts");
}

//コピーもとのメモリから格納先メモリに保存します。
//packされた10bit,12bitは16bitに展開してします。
void CnvertImage(unsigned char *dst, unsigned char *src, int srcSize, int bpp){
	int j = 0;
	switch(bpp){
		case 8:
		case 16:
			for(int i = 0; i < srcSize; i++){
				dst[i] = src[i];
			}
			break;
		case 10:
			for(int i = 0; i < srcSize; i+=5){
				dst[j++]  = src[i]    *  4 + (src[i+4] )     % 4;
				dst[j++]  = src[i]    / 64;
				dst[j++]  = src[i+1]  * 4 + (src[i+4] >> 2)  % 4;
				dst[j++]  = src[i+1]  / 64;
				dst[j++]  = src[i+2]  * 4 + (src[i+4] >> 4 ) % 4;
				dst[j++]  = src[i+2]  / 64;
				dst[j++]  = src[i+3]  * 4 + (src[i+4] >> 6 ) % 4;
				dst[j++]  = src[i+3]  / 64;
			}
			break;
		case 12:
			for(int i = 0; i < srcSize; i+=3){
				dst[j++] = src[i]   * 16 + (src[i+2] )     % 16;
				dst[j++] = src[i]   / 16;
				dst[j++] = src[i+1] * 16 + (src[i+2] >> 4) % 16;
				dst[j++] = src[i+1] / 16;
			}
			break;
		default:
			break;
	}
}

void EndianChange(unsigned char *dst, unsigned char *src, int srcSize, int bpp){
	switch(bpp){
		case 16:
		case 10:
		case 12:
			for(int i = 0; i < srcSize; i+=2){
				dst[i] = src[srcSize-i];
			}
			break;
		case 8:
		default:
			break;
	}
}

int main(int argc, char *argv[]){
	if(argc < 4){
		printf("usage:%s Width Height RawFilename\n",argv[0]);
		exit(EXIT_FAILURE);
	}

	short width, height;
	char *RawFilename;
	char FtsFilename[256];
    struct stat RawFileInfo;

	width  = atoi(argv[1]);
	height = atoi(argv[2]);
	RawFilename = argv[3];
	RawNmae2Fts(FtsFilename, RawFilename);

    if (stat(RawFilename, &RawFileInfo) == -1) {
        perror("stat");
        exit(EXIT_FAILURE);
    }

	int BinSize, FtsSize;
	int RawSize = RawFileInfo.st_size;
	int bpp = RawSize * 8 / width / height;
	//変換後のサイズを計算
	if(bpp == 10){
		BinSize = RawSize * 2 * 4 / 5;	// 8,8,8,8,(2,2,2,2)
	}else if(bpp == 12){
		BinSize = RawSize * 2 * 2 / 3;	// 8,8,(4,4)
	}else{
		BinSize = RawSize;
	}

	if(BinSize % FITS_BLOCK_SIZE > 0)
		FtsSize = BinSize / FITS_BLOCK_SIZE + 1;
	else
		FtsSize = BinSize / FITS_BLOCK_SIZE;
	FtsSize = FtsSize * FITS_BLOCK_SIZE;

	printf("depth:%dbit\n", bpp);
	printf("Raw %s %d bytes\n",RawFilename, RawSize);
	printf("Fts %s %d bytes\n",FtsFilename, FtsSize + FITS_BLOCK_SIZE);

	unsigned char *RawImage = (unsigned char *)malloc(RawSize);
	unsigned char *BinImage = (unsigned char *)malloc(BinSize);
	unsigned char *FtsImage = (unsigned char *)malloc(FtsSize);
	char *FtsHeader = (char *)malloc(FITS_BLOCK_SIZE);
	if(RawImage == NULL){
        perror("Raw malloc");
        exit(EXIT_FAILURE);
	}
	if(FtsImage == NULL){
        perror("Fts malloc");
        exit(EXIT_FAILURE);
	}

	FILE *fpRaw,*fpFts;

	fpRaw = fopen(RawFilename, "rb");
	int r = fread(RawImage, sizeof(char), RawSize, fpRaw);
	printf("Read %d bytes\n", r);
	fclose(fpRaw);

	CnvertImage(FtsImage, RawImage, RawSize, bpp);
	EndianChange(FtsImage, BinImage, BinSize, bpp);

	int offset = 0;
	sprintf(FtsHeader+offset,"%-80s", "SIMPLE  =                   T / Created by raw2fts");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"BITPIX  = %19d / %-49s", 16, "number of bits per data pixel");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"NAXIS   = %19d / %-49s", 2, "number of data axes");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"NAXIS1  = %19d / %-49s", width, "length of data axis 1");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"NAXIS2  = %19d / %-49s", height, "length of data axis 2");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"BZERO   = %19d / %-49s", 0, "data range offset");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"BSCALE  = %19d / %-49s", 1, "lscaling factor");
	offset += FITS_RECORD_SIZE;
	sprintf(FtsHeader+offset,"%-80s", "END");
	for(int i=0; i < FITS_BLOCK_SIZE; i++){
		if(*(FtsHeader+i) == 0x00)
			*(FtsHeader+i) = 0x20;
	}

	int w;
	fpFts = fopen(FtsFilename, "wb");
	w = fwrite(FtsHeader, sizeof(char), FITS_BLOCK_SIZE, fpFts);
	printf("%ld ", FITS_BLOCK_SIZE * sizeof(char));
	w = fwrite(FtsImage, sizeof(char), FtsSize, fpFts);
	printf("+ %d bytes\n", w);
	fclose(fpFts);

	free(FtsHeader);
	free(FtsImage);
	free(BinImage);
	free(RawImage);
}