#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include <jpeglib.h>
#include <argtable2.h>
#include <string.h>

const char * input_file;
const char * output_file;
const char * filter;
double times;
double percent;


/* we will be using this uninitialized pointer later to store raw, uncompressd image */
JSAMPARRAY row_pointers = NULL;


/* dimensions of the image we want to write */
JDIMENSION width;
JDIMENSION height;
int num_components;
int quality = 75;
J_COLOR_SPACE color_space;

int clamp(int a){
	if(a>255)return 255;
	if(a<0)return 0;
	return a;
}

void negate(){
  int x, y;
  if (color_space != JCS_RGB)  return;

  for (y=0; y<height; y++) {
    JSAMPROW row = row_pointers[y];
    for (x=0; x<width; x++) {
      JSAMPROW ptr = &(row[x*3]);
      //printf("Pixel at position [ %d - %d ] \
	has the following RGB values: \
	%d - %d - %d\n",
    //  x, y, ptr[0], ptr[1], ptr[2]);

      ptr[0] = 255 - ptr[0];
      ptr[1] = 255 - ptr[1];
	  ptr[2] = 255 - ptr[2];
    }
  }
}    

void brightness(){
  int x, y;
  if (color_space != JCS_RGB)  return;

  for (y=0; y<height; y++) {
    JSAMPROW row = row_pointers[y];
    for (x=0; x<width; x++) {
      JSAMPROW ptr = &(row[x*3]);
      //printf("Pixel at position [ %d - %d ] \
	has the following RGB values: \
	%d - %d - %d\n",
    //  x, y, ptr[0], ptr[1], ptr[2]);

      ptr[0] = clamp(ptr[0] + percent/100*ptr[0]);
      ptr[1] = clamp(ptr[1] + percent/100*ptr[1]);
      ptr[2] = clamp(ptr[2] + percent/100*ptr[2]);
    }
  }
}  

void contrast(){
  int x, y;
  if (color_space != JCS_RGB)  return;

  for (y=0; y<height; y++) {
    JSAMPROW row = row_pointers[y];
    for (x=0; x<width; x++) {
      JSAMPROW ptr = &(row[x*3]);
      //printf("Pixel at position [ %d - %d ] \
	has the following RGB values: \
	%d - %d - %d\n",
    //  x, y, ptr[0], ptr[1], ptr[2]);

      ptr[0] = clamp(times*(ptr[0]-127)+127);
      ptr[1] = clamp(times*(ptr[1]-127)+127);
	  ptr[2] = clamp(times*(ptr[2]-127)+127);
    }
  }
}  

void sepia(){
  int x, y;
  if (color_space != JCS_RGB)  return;

  for (y=0; y<height; y++) {
    JSAMPROW row = row_pointers[y];
    for (x=0; x<width; x++) {
      JSAMPROW ptr = &(row[x*3]);
      //printf("Pixel at position [ %d - %d ] \
	has the following RGB values: \
	%d - %d - %d\n",
    //  x, y, ptr[0], ptr[1], ptr[2]);
	double r = ptr[0];
	double g = ptr[1];
	double b = ptr[2];
	ptr[0] = clamp(0.393*r + 0.769*g + 0.189*b);
	ptr[1] = clamp(0.349*r + 0.686*g + 0.168*b);
	ptr[2] = clamp(0.272*r + 0.534*g + 0.131*b);
    }
  }
}  


void process_file(){
    if(strcmp(filter, "negate") ==0 ){
            negate();
    }
    else if(strcmp(filter, "brightness") ==0 ){
		brightness();
    }
    else if(strcmp(filter, "contrast") ==0 ){
		contrast();
    }
    else if(strcmp(filter, "sepia") ==0 ){
            sepia();
    }
}




void abort_(const char * s, ...)
{
	va_list args;
	va_start(args, s);
	vfprintf(stderr, s, args);
	fprintf(stderr, "\n");
	va_end(args);
	abort();
}


/**
 * read_jpeg_file Reads from a jpeg file on disk specified by filename and saves into the 
 * raw_image buffer in an uncompressed format.
 * 
 * \returns positive integer if successful, -1 otherwise
 * \param *filename char string specifying the file name to read from
 *
 */

void read_jpeg_file( const char *filename )
{
	/* these are standard libjpeg structures for reading(decompression) */
	struct jpeg_decompress_struct cinfo;
	struct jpeg_error_mgr jerr;
	/* libjpeg data structure for storing one row, that is, scanline of an image */
	int y;
	
	FILE *infile = fopen( filename, "rb" );
	
	if ( !infile )
	{
		abort_("Error opening input jpeg file %s!\n", filename);
	}
	/* here we set up the standard libjpeg error handler */
	cinfo.err = jpeg_std_error( &jerr );
	jpeg_create_decompress( &cinfo );
	/* this makes the library read from infile */
	jpeg_stdio_src( &cinfo, infile );
	/* reading the image header which contains image information */
	jpeg_read_header( &cinfo, TRUE );


	/* Start decompression jpeg here */
	jpeg_start_decompress( &cinfo );
	width = cinfo.output_width;
	height = cinfo.output_height;
	num_components = cinfo.out_color_components;
	color_space = cinfo.out_color_space;
	
	
	/* allocate memory to hold the uncompressed image */
	size_t rowbytes = width * num_components;
	row_pointers = (JSAMPARRAY) malloc(sizeof(j_common_ptr) * height);
	for (y=0; y<height; y++){
		row_pointers[y] = (JSAMPROW) malloc(rowbytes);
	}
	
	
	/* read one scan line at a time */
	y=0;
	JSAMPARRAY tmp = row_pointers;
	while( cinfo.output_scanline < cinfo.image_height )
	{
		y = jpeg_read_scanlines( &cinfo, tmp, 1 );
		tmp +=y;
	}
	/* wrap up decompression, destroy objects, free pointers and close open files */
	jpeg_finish_decompress( &cinfo );
	jpeg_destroy_decompress( &cinfo );
// 	free( row_pointer[0] );
	fclose( infile );
	/* yup, we succeeded! */
}




/**
 * write_jpeg_file Writes the raw image data stored in the raw_image buffer
 * to a jpeg image with default compression and smoothing options in the file
 * specified by *filename.
 *
 * \returns positive integer if successful, -1 otherwise
 * \param *filename char string specifying the file name to save to
 *
 */
void write_jpeg_file( const char *filename )
{
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;
	int y;
	JSAMPARRAY tmp;

	
	/* this is a pointer to one row of image data */
	FILE *outfile = fopen( filename, "wb" );
	
	if ( !outfile )	{
		abort_("Error opening output jpeg file %s!\n", filename );
	}
	cinfo.err = jpeg_std_error( &jerr );
	jpeg_create_compress(&cinfo);
	jpeg_stdio_dest(&cinfo, outfile);

	/* Setting the parameters of the output file here */
	cinfo.image_width = width;	
	cinfo.image_height = height;
	cinfo.input_components = num_components;
	cinfo.in_color_space = color_space;
    /* default compression parameters, we shouldn't be worried about these */
	jpeg_set_defaults( &cinfo );
	jpeg_set_quality (&cinfo, quality, TRUE);
	/* Now do the compression .. */
	jpeg_start_compress( &cinfo, TRUE );
	/* like reading a file, this time write one row at a time */
	tmp = row_pointers;
	while( cinfo.next_scanline < cinfo.image_height )
	{
		y = jpeg_write_scanlines( &cinfo, tmp, 1 );
		tmp +=y;
	}
	/* similar to read file, clean up after we're done compressing */
	jpeg_finish_compress( &cinfo );
	jpeg_destroy_compress( &cinfo );
	fclose( outfile );
	
        /* cleanup heap allocation */
	for (y=0; y<height; y++){
		free(row_pointers[y]);
	}
	free(row_pointers);
}




int main(int argc, char **argv){   
  // Options
  struct arg_file *input_file_arg = arg_file1("i", "in-file", "<input>", "Input JPEG File");
  struct arg_file *output_file_arg = arg_file1("o", "out-file" , "<output>", "Output JPEG File");
  struct arg_str *filter_arg = arg_str1("f", "filter" , "<filter>", "Filter");
  struct arg_dbl *times_arg = arg_dbl0("t", "times" , "<times>", "Multiplyer");
  struct arg_dbl *percent_arg = arg_dbl0("p", "percent" , "<percent>", "Percentage");
  struct arg_lit *help = arg_lit0("h","help", "print this help and exit");
  struct arg_end *end = arg_end(10); // maksymalna liczba błędów 10
  
  int nerrors;
  
  void *argtable[] = {input_file_arg, output_file_arg, filter_arg, times_arg, percent_arg, help, end};
  
  if (arg_nullcheck(argtable) != 0) printf("error: insufficient memory\n");
  
  times_arg->dval[0] = 1;
  percent_arg->dval[0] = 0;
  
  nerrors = arg_parse(argc, argv, argtable);

  if (help->count > 0){
     printf("Usage: point");
     arg_print_syntax(stdout, argtable,"\n");
     arg_print_glossary(stdout, argtable,"  %-25s %s\n");
     arg_freetable(argtable, sizeof(argtable)/sizeof(argtable[0]));
     return 0;
  }

  
  if (nerrors==0){
     input_file = input_file_arg->filename[0];
     output_file = output_file_arg->filename[0];
     filter = filter_arg->sval[0];
     times = times_arg->dval[0];
     percent = percent_arg->dval[0];
  }
  else{
     arg_print_errors(stderr, end, "point");
     arg_print_glossary(stderr, argtable, " %-25s %s\n");
     arg_freetable(argtable, sizeof(argtable)/sizeof(argtable[0]));
     return 1;
  }


   read_jpeg_file(input_file);
   process_file();
   write_jpeg_file(output_file);
   arg_freetable(argtable, sizeof(argtable)/sizeof(argtable[0]));
   return 0;
}