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

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

const char * input_file;
const char * output_file;
const char * filter;
const char * axis;
const char * direction;
double times;

/* ZADANIE POLOCENIE
1. old_pointers
2.width<->height
3.zaalokować row_pointers
4.przezucic piksele
5.zwolnic old_pointers*/

/* 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 flip(){
    int x, y;
    if (color_space != JCS_RGB)  return;

    if (strcmp(axis, "y") == 0) {
        for (y=0; y<height; y++) {
            JSAMPROW row = row_pointers[y];
            for (x=0; x<width/2; x++) {
                JSAMPROW ptr1 = &(row[x*3]);
                JSAMPROW ptr2 = &(row[(width-1-x)*3]);
                
                JSAMPLE tmp;
                tmp=ptr1[0]; ptr1[0]=ptr2[0]; ptr2[0]=tmp;
                tmp=ptr1[1]; ptr1[1]=ptr2[1]; ptr2[1]=tmp;
                tmp=ptr1[2]; ptr1[2]=ptr2[2]; ptr2[2]=tmp;
            }
        }
    } 
    else if (strcmp(axis, "x") == 0) {
        for (y = 0; y < height / 2; y++) {
            JSAMPROW tmp_row = row_pointers[y];
            row_pointers[y] = row_pointers[height - 1 - y];
            row_pointers[height - 1 - y] = tmp_row;
        }
    }
}

void rotate() {
    if (color_space != JCS_RGB) return;

    JSAMPARRAY old_pointers = row_pointers;
    JDIMENSION old_width = width;
    JDIMENSION old_height = height;

    width = old_height;
    height = old_width;

    size_t rowbytes = width * num_components;
    row_pointers = (JSAMPARRAY) malloc(sizeof(j_common_ptr) * height);
    for (int y = 0; y < height; y++) {
        row_pointers[y] = (JSAMPROW) malloc(rowbytes);
    }

    for (int old_y = 0; old_y < old_height; old_y++) {
        for (int old_x = 0; old_x < old_width; old_x++) {
            int new_x, new_y;

            if (strcmp(direction, "right") == 0) {
                new_x = old_height - 1 - old_y;
                new_y = old_x;
            } else {
                new_x = old_y;
                new_y = old_width - 1 - old_x;
            }

            JSAMPROW old_ptr = &(old_pointers[old_y][old_x * 3]);
            JSAMPROW new_ptr = &(row_pointers[new_y][new_x * 3]);
            new_ptr[0] = old_ptr[0];
            new_ptr[1] = old_ptr[1];
            new_ptr[2] = old_ptr[2];
        }
    }

    for (int y = 0; y < old_height; y++) {
        free(old_pointers[y]);
    }
    free(old_pointers);
}

void process_file(){
    if(strcmp(filter, "flip") == 0 ){
        flip();
    }
    else if(strcmp(filter, "rotate") == 0 ){
        rotate();
    }
}

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_str *axis_arg = arg_str0("a", "axis" , "<axis>", "Flip axis (x/y)");
  struct arg_str *direction_arg = arg_str0("d", "direction" , "<direction>", "Rotate direction");
  struct arg_dbl *times_arg = arg_dbl0("t", "times" , "<times>", "Multiplyer");
  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, axis_arg, direction_arg, times_arg, help, end};
  
  if (arg_nullcheck(argtable) != 0) printf("error: insufficient memory\n");
  
  times_arg->dval[0] = 1;
  axis_arg->sval[0] = "y";
  direction_arg->sval[0] = "right";
  
  nerrors = arg_parse(argc, argv, argtable);
  
  if (help->count > 0){
     printf("Usage: geometry");
     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];
     axis = axis_arg->sval[0];
     direction = direction_arg->sval[0];
     times = times_arg->dval[0];
  }
  else{
     arg_print_errors(stderr, end, "geometry");
     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;
}