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

// Everything here is the same as sampleprogram.c except that 
// there are differences when we have to read in the string
int main(void)
{
  char *data;
  long m,n;
  char* s = malloc(100 * sizeof(char));
    char* s2 = malloc(100 * sizeof(char));
  // char* s2;
  printf("%s%c%c\n",
	 "Content-Type:text/html;charset=iso-8859-1",13,10);
  printf("<TITLE>Multiplication results</TITLE>\n");
  printf("<H3>Multiplication results</H3>\n");

  /* Here is where the difference is */

  //  data = getenv("QUERY_STRING");   This is what we used to have

  int length = atoi(getenv("CONTENT_LENGTH"));
  int j =0;
  char c;
  c = getchar();
  data = malloc(sizeof(char) * (length + 1) );  // create space to store the whole string
  while ( c != EOF && j < length ) {
    //read in one character
    data[j] = c;
    c = getchar();
    j++;

  }

  //add the null character to the string
  data[j] = '\0';
 

 //  Now everything is the same from here on out

  printf("<p> Data is: \n <br> %s " , data);
  
  //data ends up being a string that looks something like "m=3&n=4&s=somestuff&l=someotherstuff"
  // the syntax for this is "nameOfFirstField=valueInFirstField&nameOfSecondField=valueInSecondField& etc"
  // so we'll use string tokenizer to split at every &.
  // then we can use sscanf() to separate the part that is the name of the field from the value of the field.



  if(data == NULL) {
    printf("<P>Error! Error in passing data from form to script.");
    return 0;
  }

  char delimiters[] = "&";

  char* str = strtok( data, delimiters);
  //printf("%s", data);

  if (sscanf(str, "m=%ld", &m ) == 0 ) {
    printf("<p>Invalid data! M must be a number!<br> \n");

  }
 
 str = strtok(NULL, delimiters);
 if (sscanf(str, "n=%ld", &n ) == 0 ){
   printf("<p> Invalid data! n must be a number! \n");
 }

     str = strtok(NULL, delimiters);
     sscanf(str, "s=%s", s);

     //we need to go through string and turn the pluses into spaces!
     int i;
     for (i=0; i < strlen(s); i++ ) {
       if (s[i] == '+')
	 s[i] = ' ';

     }


     str = strtok(NULL, delimiters);
     sscanf(str, "l=%s", s2);


     for (i=0; i < strlen(s2); i++) {
       if (s2[i] == '+') 
	 s2[i] = ' ';

     }


    printf("<P>The product of %ld and %ld is %ld.",m,n,m*n);
    //s stores the rest whole thing, we need to do a bit of tokenizing around the &...
    printf("<p> Your strings are \"%s\" and \"%s\"", s, s2 );
    
  
  return 0;
}