** Fossil is run as a service.
*/
#include "config.h"
#include "robot.h"
#include <assert.h>
#include <time.h>

#define POW_COOKIE  "fossil-proofofwork"

/*
** Rewrite the current page with a robot squelch captcha and return 1.
**
** Or, if valid proof-of-work is present as either a query parameter or
** as a cookie, then return 0.
*/
static int robot_proofofwork(void){

  }
  h1 = (h1 % 900000000) + 100000000;
  h2 = (h2 % 900000000) + 100000000;

  /* If there is already a proof-of-work cookie with this value
  ** that means that the user agent has already authenticated.
  */
  z = P(POW_COOKIE);
  if( z
   && (atoi(z)==h1 || atoi(z)==h2) 
   && !cgi_is_qp(POW_COOKIE) ){
    return 0;
  }

  /* Check for a proof query parameter.  If found, that means that
  ** the captcha has just now passed, so set the proof-of-work cookie
  ** in addition to letting the request through.
  */
  z = P("proof");
  if( z
   && (atoi(z)==h1 || atoi(z)==h2)
  ){
    cgi_set_cookie(POW_COOKIE,z,"/",900);
    return 0;
  }
  cgi_tag_query_parameter("proof");

  /* Ask the client to present proof-of-work */
  cgi_reset_content();
  cgi_set_content_type("text/html");
  style_header("Browser Verification");
  @ <h1 id="x1">Checking to see if you are a robot<span id="x2"></span></h1>
  @ <form method="GET">
  @ <p id="x3" style="visibility:hidden;">\
  @ Press <input type="submit" id="x5" value="Ok" focus> to continue</p>
  cgi_query_parameters_to_hidden();
  @ <input id="x4" type="hidden" name="proof" value="0">

  @ </form>
  @ <script nonce='%s(style_nonce())'>
  @ function aaa(x){return document.getElementById(x);}
  @ function bbb(h,a){
  @   aaa("x4").value=h
  @   if((a%%75)==0){
  @     aaa("x2").textContent=aaa("x2").textContent+".";
  @   }
  @   if(a>0){
  @     setTimeout(bbb,1,h+a,a-1);
  @   }else{
  @     aaa("x3").style.visibility="visible";
  @     aaa("x2").textContent="";
  @     aaa("x1").textContent="All clear";
  @     aaa("x5").focus();
  @   }
  @ }   
  k = 800 + h2%99;
  h2 = (k*k + k)/2;
  @ setTimeout(function(){bbb(%u(h1-h2),%u(k));},10);
  @ </script>
  style_finish_page();
  return 1;
}

/*
** SETTING: robot-restrict                width=40 block-text

    return 0;                /* There is a valid token= query parameter */
  }
  if( robot_proofofwork() ){
    return 1;
  }
  return 0;
}


/*
** WEBPAGE: test-robotck
**
** Run the robot_restrict() function using the value of the "name="
** query parameter as an argument.  Used for testing the robot_restrict()
** logic.
**
** Whenever this page is successfully rendered (when it doesn't go to
** the captcha) it deletes the proof-of-work cookie.  So reloading the
** page will reset the cookie and restart the verification.
*/
void robot_restrict_test_page(void){
  const char *zName = P("name");
  const char *zP1 = P("proof");
  const char *zP2 = P(POW_COOKIE);
  const char *z;
  if( zName==0 || zName[0]==0 ) zName = g.zPath;
  login_check_credentials();
  if( !g.perm.Admin ){ login_needed(0); return; }
  g.zLogin = 0;
  if( robot_restrict(zName) ) return;
  style_set_current_feature("test");
  style_header("robot_restrict() test");
  @ <h1>Captcha passed</h1>
  @
  @ <p>
  if( zP1 && zP1[0] ){
     @ proof=%h(zP1)<br>
  }
  if( zP2 && zP2[0] ){
    @ fossil_proofofwork=%h(zP2)<br>
    cgi_set_cookie(POW_COOKIE,"",0,-1);
  }
  z = db_get("robot-restrict",robot_restrict_default());
  if( z && z[0] ){
    @ robot-restrict=%h(z)</br>
  }
  @ </p>
  @ <p><a href="%R/test-robotck/%h(zName)">Retry</a>
  style_finish_page();
}