#!/bin/ch
/* Copyright (c) 2001 by SoftIntegration, Inc. All Rights Reserved */
/* Web Calculator source code written in Ch */

#include <cgi.h>

void sendApplet(char *x, char *y, char *expr) {
    class CResponse Response;

    Response.setContentType("application/x-chs"); 
    Response.begin();
    printf("#include<stdio.h>\n");
    printf("int main() {\n");
    printf("  double x = %s;\n", x);
    printf("  double y = %s;\n", y);
    printf("  printf(\"x = %%f, \", x);\n");
    printf("  printf(\"y = %%f \\n\", y);\n");
    printf("  printf(\"%s = %%f\\n\", %s);\n", expr, expr);
    printf("  getchar();\n"); // Hold result for display in windows 
    printf("}\n");
    Response.end();
}

void errorHandler(char *reason) {
    class CResponse Response;

    Response.begin();
    Response.title("Web Calculator");

    fprintf stdout << ENDFILE
      <H3>Web Calculator Failed</H3>
      Your mathematical expression has not been submitted to Web Calculator
       because $reason.
       <A HREF="/chhtml/toolkit/demos/cgi/sample/calculator.html">Try again.</A>
       <hr>
       <A HREF="http://www.softintegration.com" target="_top">
       <img src="/chhtml/images/poweredbych.gif" alt="Powered by Ch"></A>
     ENDFILE
     Response.end();
     exit(0);
}

int main() {
    class CRequest Request;
    int num;
    chstrarray name, value;

    num = Request.getFormNameValue(name, value);
    if(num==0)
      errorHandler("you submitted nothing");
    if(!value[0]) 
      errorHandler("you didn't input x value");
    else if(!isnum(value[0])) 
      errorHandler("x is not a valid number");
    else if(!isnum(value[1])) 
      errorHandler("y is not a valid number");
    if(!value[2]) 
      errorHandler ("you didn't input mathematical expression");
    sendApplet(value[0], value[1], value[2]);
}