/****************************
    file: count.cpp

    Initially written by Keith Oxenrider October 25, 1998

    For use on the web as a cgi program.  Is activated by
    calling the program as an image, i.e., IMG SRC="/cgi-bin/count.cgi?countdatafile".
    to increment counter without having a visible display, invoke as follows:
         IMG SRC="/cgi-bin/count.cgi?countdatafile" HEIGHT="0" WIDTH="0"

    If the last character in the input string is an '!'
       then the counter will not be incremented, just displayed.

    The program will automagically create a new count file if the
    filename selected does not exist.

    There is a companion program called 'view_counts' that is used
    to look at all the counter stored along with the last access time.

    Modified to include date/time stamp on 3/1/1999.
    Security fix on 11/18/2003 to eliminate directory transversals.
    Converted on 03/06/2006 to C++ and to generate Microsoft's Bitmaps (DIB).


****************************/

#include <cctype>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#ifdef WIN32
//for Setting "stdout" to have binary mode
    #include <fcntl.h>
    #include <io.h>
#endif

#include "mkBitMap.hpp"

#define TRUE 1
#define FALSE 0
#define MAXLINELENGTH 1024

// hardcoded path to directory that contains data files 
#ifdef WIN32
    char m_strPath[] = "countdata\\";
#else // presumed *nix 
    char m_strPath[] = "countdata/";
#endif


void dumpDigits(const char *numb){
    CBitMap myBitMap(numb);
    printf("Content-type: image/x-ms-bmp\n\n");
#ifdef WIN32
   // Set "stdout" to have binary mode:
   _setmode( _fileno( stdout ), _O_BINARY );
   // no error checking/handling to simplify coding
#endif
    myBitMap.Dump(stdout);
    exit(0);
}

/************************
 *
 *  main()
 *
 ************************/

int main () {
    unsigned long count;
    FILE *fin = NULL;
    char numb[MAXLINELENGTH], *input;
    int len, i, write, wipe;
    char filename[MAXLINELENGTH];
    struct tm *time_date;
    time_t timer;

    input = getenv("QUERY_STRING");

    if (input == NULL){// no file for counts 
        dumpDigits("0100000000");
        return 0;
    }

    len = strlen(input);
    // if input is too high, something is wrong, exit
    if (len >= MAXLINELENGTH){
        dumpDigits("0200000000");
        return 0;
    }

   // check for invalid characters (thanks infamous42md!)
    for (i=0; i<len; i++){
        // only allow alpha numeric characters and underscores
        if (input[i] == '_') continue;
        if (!isalnum(input[i])){
            if (input[i] != '!'){//this is if we want to display count without incrementing
                dumpDigits("0300000000");
                return 0;
            }
        }
    }

   // check for write flag on end of filename and set accordingly
    write = TRUE;
    if (input[len-1] == '!'){
        write = FALSE;
        input[len-1] = '\0';
    }

    strncpy(filename, m_strPath, MAXLINELENGTH);
    strncat(filename, input, MAXLINELENGTH);

    numb[0] = '\0';

    // open the file that holds numeric counter value
    if ((fin = fopen(filename, "r")) == NULL)
        strcpy(numb, "0");
    else{
        fgets(numb, MAXLINELENGTH, fin);
        fclose(fin);
    }

    i = 0; /* stick a NULL after what is supposed to be the count */
    while (numb[i] != ' ' && numb[i] != '\0')
        i++;
    numb[i] = '\0';

    len = strlen(numb);

    // if contents of counter file are not recognizable input, set counter to zero 
    wipe = FALSE;
    for (i=0; i<len; i++){
        if (!isdigit(numb[i]))
            wipe = TRUE;
        if (i>10) // hard-coded for 10 digits, must change if you want more 
            wipe = TRUE;
        if (wipe){
            strcpy(numb, "0");
            break;
        }
    }

    count = atol(numb);

    if (count >= LONG_MAX)//if the value rolls over, reset to zero (gives you 2^31, or 2,147,483,647 counts)
        count = 0;

    if (write){// write new counter data to file
        count++;
        FILE *fout = fopen(filename, "w");
        if (fout){
            fprintf(fout, "%ld", count);
            // get the time and format to look nice
            time(&timer);
            time_date = localtime(&timer);
            fprintf(fout, " %02d/%02d/%d %02d:%02d:%02d", time_date->tm_mon +1, time_date->tm_mday, time_date->tm_year+1900, time_date->tm_hour, time_date->tm_min, time_date->tm_sec);
            fclose(fout);
        }else{
            perror("count file not open");
            dumpDigits("0400000000");
        }
    }

    sprintf(numb, "%ld", count);
    dumpDigits(numb);
    return 0;//should never get here, dumpDigits calls exit
}