#include <stdio.h>
#include <stdlib.h>
#include <cs50.h>

int main(int argc, char *argv[])
{
    //check command line arguments and make sure they are more than one
    if (argc != 2)
    {
        printf("Usage: ./recover image\n");
        return 1;
    }
    
    FILE *inptr = fopen (argv[1], "r");
    //if file does not exist return an error
    if (inptr == NULL)
    {
        printf("Error! Could not recover\n");
        return 2;
    }
    //create filename and buffer arrays
    unsigned char buffer[512];
    char filename[8];
    
    //set file count to 0
    int jpeg_count = 0;
    int picture = 0;
    int found_jpeg = 0;
    
    //new file I'll be writing to
    FILE* outptr = NULL;

        while (fread (buffer, sizeof(buffer), 1, inptr) == 1)
        {
            //find the beginning of jpg signature
            if (buffer[0] == 0xff && buffer[1] == 0xd8 && buffer[2] == 0xff && (buffer[3] & 0xf0) == 0xe0)
            {
                //for first jpeg found
              if (jpeg_count == 0)
              {
                  sprintf (filename, "%03i.jpg", jpeg_count);
                  jpeg_count++;
                  
                  //open first file i.e. 000.jpg
                  outptr = fopen (filename, "w");
              }
              //if jpeg already found
              else 
              {
                  //close current file that was being written to
                  fclose(outptr);
                  jpeg_count++;
                  sprintf (filename, "%03i.jpg", jpeg_count);
                  
                  //open new file just created to start writing data into it
                  outptr = fopen (filename, "w");
                  fwrite (buffer, sizeof(buffer), 1, outptr);
              }
            }
            
           if (outptr != NULL)
              {
                  //keep writing to current file if already in open jpeg
                  fwrite (&buffer, sizeof(buffer), 1, outptr);
              }
        }
        //close input file
    fclose(inptr);
    
    //close output file
    fclose(outptr);
    return 0;
}