/**
 * Make a program to copy all JPEG images of memory card to recover all thoses deleted images
   by looking for JPEG signature.
 */

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



int main(int argc, char *argv[])
{

    // one command-line argument
    if (argc != 2)
    {
        fprintf(stderr, "Usage: enter name of forensic image\n");
        return 1;
    }


    //name of the memroy card file
    char *card_raw = argv[1];

    // open memory card file that is the input // cardfile is a file and card_raw is the name of the file
    FILE *cardfile  = fopen(card_raw, "r");
    if (cardfile == NULL)
    {
        fprintf(stderr, "Could not open %s\n", card_raw);
        return 2;
    }



    //define data structure for having exactly 1 byte
    typedef uint8_t BYTE;


    //to store bytes of the size of an array = 512 =block size long  (size of an array of 512 which is 1 byte long) => store memory which bunch of 512 bytes called buffer
    BYTE buffer[512];

    //count for number of JPEG file - should get total of 50 with raw
    int count = 0;
    FILE *image = NULL;

    //read the memory card until end of file (end of memory card) so no more 512 block left, where size of block is 512 from FAT
    while (fread(buffer, 512, 1, cardfile) == 1)
    {
        //check the first 4 bytes pattern to find the JPEG signature (fourth byte 0Xe (0 à 7 ou a à f))
        if (buffer [0] == 0xff && buffer [1] == 0xd8 && buffer [2] == 0xff && (buffer [3] == 0xe0 || buffer[3] == 0xe1))
        {

            //if an outfile is open, close it to than start a new file
            if (count > 0)
            {
                fclose(image);
            }


            //if JPEG signature start a new file so create the file to be opened to be able to copy the JPEG image from memory card

            //create name of the file with char for jpeg filames with 3 digits => 000.jpg (7 caracters) + "\ 0" (+1 caracter) = total of 8caracters
            char filename[8];
            //create a name for each file
            sprintf(filename,"%03i.jpg", count);
            //increase number of filename for next jpg found => 000.jpg, 001.jpg. 002.jpg etc...

            //open the file
            image = fopen(filename, "w");
            count ++;

            if (image == NULL);
            {
                fprintf(stderr, "Could not open new file\n");
                return 3;
            }

             //write the new file so copy the memory card ofr one image at a time
            fwrite(buffer, 512, 1, image);
        }

        // write image by image // write the 0 as 0 if blank space
        //if ( size != 1) //stop reading because it s
        // fin c'est le début d'un autre JPEG

        //if no JPEG signature, just copy on the file until closed or end of file (when found a new signature file will be closed)
        if (count > 0)
        {
            //write all the blocks after the JPEG signature
            fwrite(buffer, 512, 1, image);
        }

    }
    // close outfile each one at the time ( when encounter another signature)
    fclose(image);

    // close memory file
    fclose(cardfile);


    // success
    return 0;
}