/****************************************************************************
 * recover.c
 *
 * Computer Science 50
 * Problem Set 5
 *
 * recovers images from .raw file. if no arg is supplied, automatically opens
 * supplied cs50 file. if user enters a filename, uses it instead.
 ***************************************************************************/

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

#define BLOCKSIZE 512;

typedef uint8_t BYTE;

bool byte_check(BYTE bytes[]);
//bool in(BYTE bytes[]);


int
main(int argc, char *argv[])
{
    FILE *inptr = fopen("card.raw", "r");

    if (inptr == NULL){
        printf("something went wrong with the file\n 35\n\n");
        return (2);
    }
    BYTE buffer[512]; //buffer to store bytes.

    int picNum = 1;
    char fileName[3];
    sprintf(fileName, "%.2d", picNum);

    // write the bytes to the buf
//    printf("writing to buffer....");
    for (int i = 0; i < 512; i++){
        if (feof(inptr)){// && ferror(inptr)){ //if we have reached the end of the file
            break;
            printf("end of file\n");
        }
        fwrite(&buffer[i], 1, 1, inptr);
    }

    //while we have not reached the end of the file
    while (!feof(inptr) || !ferror(inptr)){

        if (byte_check(buffer)){ //if bytes are the headers
            // open output file
            FILE *outptr = fopen(fileName, "w");
            printf("validated.... opening outfile.....\n");

            if (outptr == NULL){
                fclose(inptr);
                fprintf(stderr, "Could not create file %d.\n", picNum);
                return 3;
            }
            do{
                printf("writing out picture...\n");
                for (int i = 0; i < 512; i++) //write bytes into buffer
                    fwrite(&buffer, 1, 1, inptr);

                for (int i = 0; i < 512; i++){
                    if (feof(inptr) < 1) //if we have reached the end of the file
                        break;
                    fwrite(&buffer[i], 1, 1, outptr);
                }
            } while(byte_check(buffer) == false);

            fclose(outptr);
            picNum++;
        }
        // write the bytes to the buffer
//        printf("writing to buffer....");
        for (int i = 0; i < 512; i++){
            if (feof(inptr)){// && ferror(inptr)){ //if we have reached the end of the file
                break;
                printf("end of file\n");
            }
            fwrite(&buffer[i], 1, 1, inptr);
        }
    }
    // close infile
    fclose(inptr);

    // done
    return 0;
}



/*
 * takes in the jpeg formatted array and checks to see if it is
 * likely the jpeg head. returns true if it is, else returns false
 */

bool
byte_check(BYTE bytes[]){
    // 0xff = 255, 0xd8 = 216, 0xe0 = 224, 0xe1 = 225
    if (bytes[0] == 0xff && bytes[1] == 0xd8 && bytes[2] == 0xff &&
        (bytes[3] == 0xe0 || bytes[3] == 0xe1))
        return true;
    return false;
}

/*// checks to see if the signature exists in any part of the buffer*/
/*bool in(BYTE bytes[]){*/
/*    for (int i = 0; i < 508; i++){*/
/*        if (bytes[i] == 0xff && bytes[i + 1] == 0xd8 && bytes[i + 2] == 0xff &&*/
/*            (bytes[i+ 3] == 0xe0 || bytes[i+ 3] == 0xe1))*/
/*            return true;        */
/*    }*/
/*    return false;*/
/*}*/