#include <stdio.h>
#include <stdlib.h>
#include "en-decrypt.h"
#include "usefulfunc.h"
#include <string.h>
#include <math.h>
#include <unistd.h>
#include <stdarg.h>
#include <time.h>

char make_numeric(char ch)
{
    if(ch<91 && ch>63) return ch-16;
    if(ch<123 && ch>95) return ch-48;
    if(ch<58 && ch>47) return ch;
    return ch+16;
}

char* strip(char* str,int length)
{
    char *start=str,*end=&str[length-1];

    while(*start>0 && *start<33 || *start==127) ++start;
    if(!*start) return start;

    while(*end>=0 && *end<33 || *end==127) --end;
    ++end;
    *end=0;

    return start;

}

int main()
{

    int shift,len_chshift,init,len_filename,i=0;
    char *chshift,*line=NULL,*decrypted_line,*stripped_line,chinit,chlen_chshift;
    char *filename=NULL,*newfilename=NULL;
    FILE *oldfile=NULL;
    FILE *newfile=NULL;
    size_t lenline,len=0;


    printf("-9");
    /*FILENAME*/
    printf("Enter the file name: ");
    /*printf("-8");*/
    filename=getIn();
    /*printf("-7");*/
    if(!access(filename,F_OK))
    {
        len_filename=strlen(filename);
        /*printf("-6");*/
        i=len_filename;
        while(filename[i]!='.') --i;
        chlen_chshift=filename[i-1];
        chlen_chshift=make_numeric(chlen_chshift);
        len_chshift=chlen_chshift-48;
        /*printf("-5");*/
        chshift=calloc(len_chshift+1,1);
        /*NEWFILENAME*/
        newfilename=calloc(i+1,1);
        /*printf("-4");*/
        strncpy(newfilename,filename,i);
        /*printf("-3");*/
        strcat(newfilename,"(decrypted).txt");
        /*printf("-2");*/
        chinit=make_numeric(filename[0]);
        init=chinit-48;
        /*SHIFT*/
        i=0;
        /*printf("-1");*/
        while(i!=len_chshift)
        {
            chshift[i]=make_numeric(filename[(i+1)*init]);
            ++i;
        }
        /*printf("0");*/
        shift=atoi(chshift);

        /*printf("1");*/
        if(!(oldfile=fopen(filename,"r")))
        {
            perror("Error");
            if(newfilename) free(newfilename);
            if(filename) free(filename);
            if(chshift) free(chshift);
            exit(1);
        }
        /*printf("2");*/

        if(!(newfile=fopen(newfilename,"+ab")))
        {
            perror("Error");
            if(newfilename) free(newfilename);
            if(filename) free(filename);
            if(chshift) free(chshift);
            fclose(oldfile);
            exit(1);
        }
        while ((lenline = getline(&line, &len, oldfile)) != -1)
        {
            stripped_line=strip(line,lenline);
            decrypted_line=caesar_decrypt(stripped_line, &shift);
            if(!decrypted_line)
            {
                printf("Could not allocate memory\n");
                if(newfilename) free(newfilename);
                if(filename) free(filename);
                if(chshift) free(chshift);
                exit(1);
            }

            fprintf(newfile,"%s\n",decrypted_line);

            if(decrypted_line) free(decrypted_line);
            decrypted_line=NULL;

            free(line);
            line=NULL;
            stripped_line=NULL;
            decrypted_line=NULL;
        }
        free(line);
        line=NULL;
    }
    else
    {
        printf("Cannot access the file.");
        if(filename) free(filename);
        exit(0);
    }

    if(newfilename) free(newfilename);
    if(filename) free(filename);
    if(chshift) free(chshift);
    fclose(oldfile);
    fclose(newfile);
    return 0;
}