#!/usr/bin/perl

# next require defines: $helm_dir, $html_link
require "/usr/lib/helm/configuration.pl";
use HTTP::Daemon;
use HTTP::Status;
use HTTP::Request;
use LWP::UserAgent;
use DB_File;

my $cont = "";
my $d = new HTTP::Daemon LocalPort => 8081;
tie(%map, 'DB_File', 'urls_of_uris.db', O_RDONLY, 0664);
print "Please contact me at: <URL:", $d->url, ">\n";
print "helm_dir: $helm_dir\n";
$SIG{CHLD} = "IGNORE"; # do not accumulate defunct processes
while (my $c = $d->accept) {
 if (fork() == 0) {
    while (my $r = $c->get_request) {
        #CSC: mancano i controlli di sicurezza
        
        $cont = "";
        my $cicuri = $r->url; 
        $cicuri =~ s/^[^?]*\?url=(.*)/$1/;
        print "*".$r->url."\n";
        my $http_method = $r->method;
        my $http_path = $r->url->path;
        if ($http_method eq 'GET' and $http_path eq "/get") {
            my $filename = $cicuri;
            $filename =~ s/cic:(.*)/$1/;
            $filename =~ s/theory:(.*)/$1/;
            $filename = $helm_dir.$filename.".xml";
            my $resolved = $map{$cicuri};
            print "$cicuri ==> $resolved ($filename)\n";
            if (stat($filename)) {
               print "Using local copy\n";
               open(FD, $filename);
               while(<FD>) { $cont .= $_; }
               close(FD);
               my $res = new HTTP::Response;
               $res->content($cont);
               $c->send_response($res);
            } else {
               print "Downloading\n";
               $ua = LWP::UserAgent->new;
               $request = HTTP::Request->new(GET => "$resolved");
               $response = $ua->request($request, \&callback);
               
               print "Storing file\n";
               open(FD, $filename);
               print FD $cont;
               close(FD);

               my $res = new HTTP::Response;
               $res->content($cont);
               $c->send_response($res);
            }
        } elsif ($http_method eq 'GET' and $http_path eq "/annotate") {
            my $do_annotate = ($cicuri =~ /\.ann$/);
            my $target_to_annotate = $cicuri;
            $target_to_annotate =~ s/(.*)\.ann$/$1/ if $do_annotate;
            my $filename = $cicuri;
            $filename =~ s/cic:(.*)/$1/;
            $filename =~ s/theory:(.*)/$1/;
            my $filename_target = $helm_dir.$filename if $do_annotate;
            $filename = $helm_dir.$filename.".xml";
            $filename_target =~ s/(.*)\.ann$/$1.xml/ if $do_annotate;
            my $resolved = $map{$cicuri};
            my $resolved_target = $map{$target_to_annotate} if $do_annotate;
            if ($do_annotate) {
               print "($cicuri, $target_to_annotate) ==> ($resolved + $resolved_target) ($filename)\n";
        } elsif ($http_method eq 'GET' and $http_path eq "/getwithtypes") {
            my $do_annotate = ($cicuri =~ /\.types$/);
            my $target_to_annotate = $cicuri;
            $target_to_annotate =~ s/(.*)\.types$/$1/ if $do_annotate;
            my $filename = $cicuri;
            $filename =~ s/cic:(.*)/$1/;
            $filename =~ s/theory:(.*)/$1/;
            my $filename_target = $helm_dir.$filename if $do_annotate;
            $filename = $helm_dir.$filename.".xml";
            $filename_target =~ s/(.*)\.types$/$1.xml/ if $do_annotate;
            my $resolved = $map{$cicuri};
            my $resolved_target = $map{$target_to_annotate} if $do_annotate;
            if ($do_annotate) {
               print "($cicuri, $target_to_annotate) ==> ($resolved + $resolved_target) ($filename)\n";
             } else {
               print "$cicuri ==> $resolved ($filename)\n";
            }

            # Retrieves the annotation

            if (stat($filename)) {
               print "Using local copy for the types\n";
               open(FD, $filename);
               while(<FD>) { $cont .= $_; }
               close(FD);
            } else {
               print "Downloading the types\n";
               $ua = LWP::UserAgent->new;
               $request = HTTP::Request->new(GET => "$resolved");
               $response = $ua->request($request, \&callback);
               
               print "Storing file for the types\n";
               open(FD, $filename);
               print FD $cont;
               close(FD);
            }
            my $annotation = $cont;

            # Retrieves the target to annotate

            $cont = "";
            if ($do_annotate) {
               if (stat($filename_target)) {
                  print "Using local copy for the file to type\n";
                  open(FD, $filename_target);
                  while(<FD>) { $cont .= $_; }
                  close(FD);
               } else {
                  print "Downloading the file to type\n";
                  $ua = LWP::UserAgent->new;
                  $request = HTTP::Request->new(GET => "$resolved_target");
                  $response = $ua->request($request, \&callback);
               
                  print "Storing file for the file to type\n";
                  open(FD, $filename_target);
                  print FD $cont;
                  close(FD);
               }
            }
            my $target = $cont;

            # Merging the annotation and the target

            $target =~ s/<\?xml [^?]*\?>//sg;
            $target =~ s/<!DOCTYPE [^>]*>//sg;
            $annotation =~ s/<\?xml [^?]*\?>//sg;
            $annotation =~ s/<!DOCTYPE [^>]*>//sg;
            my $merged = <<EOT;
<?xml version="1.0" encoding="UTF-8"?>
<cicxml uri="$target_to_annotate">
$target
<ALLTYPES>
$annotation
</ALLTYPES>
</cicxml>
EOT

            # Answering the client

            my $res = new HTTP::Response;
            $res->content($merged);
            $c->send_response($res);
        } elsif ($http_method eq 'GET' and $http_path eq "/getdtd") {
            my $filename = $cicuri;
            $filename = $helm_dir."/dtd/".$filename;
            print "DTD: $cicuri ==> ($filename)\n";
            if (stat($filename)) {
               print "Using local copy\n";
               open(FD, $filename);
               while(<FD>) { $cont .= $_; }
               close(FD);
               my $res = new HTTP::Response;
               $res->content($cont);
               $c->send_response($res);
            } else {
               die "Could not find DTD!";
            }
        } elsif ($http_method eq 'GET' and $http_path eq "/conf") {
            my $quoted_html_link = $html_link;
            $quoted_html_link =~ s/&/&amp;/g;
            $quoted_html_link =~ s/</&lt;/g;
            $quoted_html_link =~ s/>/&gt;/g;
            $quoted_html_link =~ s/'/&apos;/g;
            $quoted_html_link =~ s/"/&quot;/g;
            print "Configuration requested, returned #$quoted_html_link#\n";
	    $cont = "<?xml version=\"1.0\"?><html_link>$quoted_html_link</html_link>";
            my $res = new HTTP::Response;
            $res->content($cont);
            $c->send_response($res);
        } else {
            print "INVALID REQUEST!!!!!\n";
            $c->send_error(RC_FORBIDDEN)
        }
    }
    $c->close;
    undef($c);
    print "\nCONNECTION CLOSED\n\n";
    exit;
  } # fork
}

#================================

sub callback
{
 my ($data) = @_;
 $cont .= $data;
}