#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;


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]);

      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]);
      
      double r = ptr[0] + (percent / 100.0) * ptr[0];
      double g = ptr[1] + (percent / 100.0) * ptr[1];
      double b = ptr[2] + (percent / 100.0) * ptr[2];

      ptr[0] = r < 0 ? 0 : (r > 255 ? 255 : (unsigned char)r);
      ptr[1] = g < 0 ? 0 : (g > 255 ? 255 : (unsigned char)g);
      ptr[2] = b < 0 ? 0 : (b > 255 ? 255 : (unsigned char)b);
    }
  }
}

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]);
      
      double r = times * (ptr[0] - 127.0) + 127.0;
      double g = times * (ptr[1] - 127.0) + 127.0;
      double b = times * (ptr[2] - 127.0) + 127.0;

      ptr[0] = r < 0 ? 0 : (r > 255 ? 255 : (unsigned char)r);
      ptr[1] = g < 0 ? 0 : (g > 255 ? 255 : (unsigned char)g);
      ptr[2] = b < 0 ? 0 : (b > 255 ? 255 : (unsigned char)b);
    }
  }
}

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]);
      
      double r = ptr[0];
      double g = ptr[1];
      double b = ptr[2];
      
      double nr = 0.393 * r + 0.769 * g + 0.189 * b;
      double ng = 0.349 * r + 0.686 * g + 0.168 * b;
      double nb = 0.272 * r + 0.534 * g + 0.131 * b;

      ptr[0] = nr < 0 ? 0 : (nr > 255 ? 255 : (unsigned char)nr);
      ptr[1] = ng < 0 ? 0 : (ng > 255 ? 255 : (unsigned char)ng);
      ptr[2] = nb < 0 ? 0 : (nb > 255 ? 255 : (unsigned char)nb);
    }
  }
}


void process_file() {
    if(strcmp(filter, "negate") == 0) {
        negate();
    }
    else if(strcmp(filter, "contrast") == 0) {
        contrast();
    }
    else if(strcmp(filter, "brightness") == 0) {
        brightness();
    }
    else if(strcmp(filter, "sepia") == 0) {
        sepia();
    }
    else {
        printf("Nieznany filtr: %s\n", filter);
    }
}


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

void read_jpeg_file( const char *filename )
{
	struct jpeg_decompress_struct cinfo;
	struct jpeg_error_mgr jerr;
	int y;
	
	FILE *infile = fopen( filename, "rb" );
	
	if ( !infile )
	{
		abort_("Error opening input jpeg file %s!\n", filename);
	}
	cinfo.err = jpeg_std_error( &jerr );
	jpeg_create_decompress( &cinfo );
	jpeg_stdio_src( &cinfo, infile );
	jpeg_read_header( &cinfo, TRUE );

	jpeg_start_decompress( &cinfo );
	width = cinfo.output_width;
	height = cinfo.output_height;
	num_components = cinfo.out_color_components;
	color_space = cinfo.out_color_space;
	
	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);
	}
	
	y=0;
	JSAMPARRAY tmp = row_pointers;
	while( cinfo.output_scanline < cinfo.image_height )
	{
		y = jpeg_read_scanlines( &cinfo, tmp, 1 );
		tmp +=y;
	}
	jpeg_finish_decompress( &cinfo );
	jpeg_destroy_decompress( &cinfo );
	fclose( infile );
}

void write_jpeg_file( const char *filename )
{
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;
	int y;
	JSAMPARRAY tmp;

	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);

	cinfo.image_width = width;	
	cinfo.image_height = height;
	cinfo.input_components = num_components;
	cinfo.in_color_space = color_space;
	jpeg_set_defaults( &cinfo );
	jpeg_set_quality (&cinfo, quality, TRUE);
	jpeg_start_compress( &cinfo, TRUE );
	tmp = row_pointers;
	while( cinfo.next_scanline < cinfo.image_height )
	{
		y = jpeg_write_scanlines( &cinfo, tmp, 1 );
		tmp +=y;
	}
	jpeg_finish_compress( &cinfo );
	jpeg_destroy_compress( &cinfo );
	fclose( outfile );
	
	for (y=0; y<height; y++){
		free(row_pointers[y]);
	}
	free(row_pointers);
}

int main(int argc, char **argv){   
  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 to apply: negate, brightness, contrast, sepia");
  struct arg_dbl *times_arg = arg_dbl0("t", "times" , "<times>", "Multiplyer");
  struct arg_dbl *percent_arg = arg_dbl0("p", "percent" , "<percent>", "Percent for brightness");
  struct arg_lit *help = arg_lit0("h","help", "print this help and exit");
  struct arg_end *end = arg_end(10); 
  
  int nerrors;
  
  // POPRAWIONE: Dodano input_file_arg do tablicy (inaczej komenda -i nie zadziała)
  void *argtable[] = {input_file_arg, percent_arg, output_file_arg, filter_arg, times_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];
     percent = percent_arg->dval[0];
     times = times_arg->dval[0]; // To też musi być, żeby wzór na kontrast miał z czego liczyć!
  }
  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;
}