#!/usr/bin/perl

use strict;
use warnings;
use CGI qw ( :standard );
use Fcntl qw ( :flock );
use XML::Parser;

if (param) {
   my ($parser, $document, $users);
   local($::flag);
   $::flag=0; 
   open(USERS, "../../xml_final/users/users.xml") || 
      die "Could not open users.xml $!";
   flock(USERS, LOCK_SH);

print header, start_html(-title => "Login" ,-style => {
      -src => "../../xml_final/db.css"}), title ("please login");
print start_html;

   $parser= new XML::Parser();
   $parser->setHandlers(
	Start => \&start_handler,
        Char  => \&char_handler
   );
   
   $document = $parser->parse (\*USERS);
   close (USERS);

   sub start_handler{
      my ($expat, $element, %attributes) =@_;
      if ($::flag==0 && $element eq "username") {
         $::flag=1;
      }

      if ($::flag==1 && $element eq "password") {
         $::flag=2;
      } 
   }

   sub char_handler {
        my ($expat, $text) =@_;
	if ($::flag==1 && $text eq (param("username"))) {
	   $::flag=1;
        } 

        if ($::flag==2 && $text eq (param("password"))) {
           print h1("LOGIN IN IS ALL GOOD");
	   print redirect("viewdb.pl?username=(param(username)");
	   print end_html;
        }
        elsif ($::flag==2 && $text ne (param("password"))) {
	   print h1 ("incorrect password");
	   $::flag=0;
           
   	   print p({-align=>'CENTER'},a{-href=>"login.pl"},"Try Agian?");
           print end_html;
           #print a link back to login.pl	
       }
   }
}
else {
   print header, start_html(-title => "Login" ,-style => {
      -src => "../../xml_final/db.css"}), title ("please login");
   print start_form;
   print h1({-align=>'CENTER'}, "Please login");
   print p({-align=>'CENTER'},"username:", textfield(
      -NAME=>"username"
	));
   print p({-align=>'CENTER'},"password:", password_field(
      -NAME=>"password"
	));
   print p({-align=>'CENTER'},submit("send"),reset);

   print end_form;
   print p({-align=>'CENTER'},a{-href=>"newuser.pl"},"New User?");

   print end_html;
}