#
# TWiki Enterprise Collaboration Platform, http://TWiki.org/
#
# Copyright (C) 2000-2006 TWiki Contributors.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version. For
# more details read LICENSE in the root of this distribution.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# As per the GPL, removal of this notice is prohibited.
#
package TWiki::Configure::Checkers::CGISetup;

use strict;

use base 'TWiki::Configure::Checker';

use File::Spec;
use FindBin;

sub ui {
    my $this = shift;
    my $block = '';

    # Detect whether mod_perl was loaded into Apache
    $TWiki::cfg{DETECTED}{ModPerlLoaded} =
      ( exists $ENV{SERVER_SOFTWARE} &&
          ( $ENV{SERVER_SOFTWARE} =~ /mod_perl/ ));

    # Detect whether we are actually running under mod_perl
    # - test for MOD_PERL alone, which is enough.
    $TWiki::cfg{DETECTED}{UsingModPerl} = ( exists $ENV{MOD_PERL} );

    $TWiki::cfg{DETECTED}{ModPerlVersion} =
      eval 'use mod_perl; return $mod_perl::VERSION';

    # Get the version of mod_perl if it's being used
    if ( $TWiki::cfg{DETECTED}{UsingModPerl} ) {
        $block .= $this->setting(
            '', $this->WARN(<<HERE));
You are running <tt>configure</tt> with <tt>mod_perl</tt>. This
is risky because mod_perl will remember old values of configuration
variables. You are *highly* recommended not to run configure under
mod_perl (though the rest of TWiki can be run with mod_perl, of course)
HERE
    }

    # Check for potential CGI.pm module upgrade
    # CGI.pm version, on some platforms - actually need CGI 2.93 for
    # mod_perl 2.0 and CGI 2.90 for Cygwin Perl 5.8.0.  See 
    # http://perl.apache.org/products/apache-modules.html#Porting_CPAN_modules_to_mod_perl_2_0_Status
    if( $CGI::VERSION < 2.93 ) {
        if ( $Config::Config{osname} eq 'cygwin' && $] >= 5.008 ) {
            # Recommend CGI.pm upgrade if using Cygwin Perl 5.8.0
            $block .= $this->setting(
                '', $this->WARN( <<HERE ));
Perl CGI version 3.11 or higher is recommended to avoid problems with
attachment uploads on Cygwin Perl.
HERE
        } elsif( $TWiki::cfg{DETECTED}{ModPerlVersion} &&
                   $TWiki::cfg{DETECTED}{ModPerlVersion} >= 1.99 ) {
            # Recommend CGI.pm upgrade if using mod_perl 2.0, which
            # is reported as version 1.99 and implies Apache 2.0
            $block .= $this->setting(
                '', $this->WARN( <<HERE ));
Perl CGI version 3.11 or higher is recommended to avoid problems with
mod_perl.
HERE
        }
    }

    #OS
    my $n = ucfirst(lc($Config::Config{osname})).' '.
      $Config::Config{osvers}.' ('.
        $Config::Config{archname}.')';
    $block .= $this->setting("Operating system", $n);

    # Perl version and type
    $n = $];
    $n .= " ($Config::Config{osname})";
    $block .= $this->setting('Perl version', $n);

    # Perl @INC (lib path)
    $block .= $this->setting(
        '@INC library path', join(CGI::br(), @INC ).
          $this->NOTE(<<HERE));
This is the Perl library path, used to load TWiki modules,
third-party modules used by some plugins, and Perl built-in modules.
HERE

    $block .= $this->setting(
        'CGI bin directory', $this->_checkBinDir());

    # Turn off fatalsToBrowser while checking module loads, to avoid
    # load errors in browser in some environments.
    $CGI::Carp::WRAP = 0;    # Avoid warnings...

    # Check that the TWiki.pm module can be found
    eval 'require TWiki';
    my $mess = '';
    if ($@) {
        $mess = $@;
        $mess = $this->ERROR(
            'TWiki.pm could not be loaded. The error was:').
              CGI::pre($mess).
                  $this->ERROR(<<HERE);
Check path to <code>twiki/lib</code> and check that LocalSite.cfg is
present and readable
HERE
    } else {
        $mess = 'TWiki.pm (Version: <strong>'.$TWiki::VERSION.'</strong>) found';
    }
    $block .= $this->setting(
        'TWiki module in @INC path', $mess);

    # Check that each of the required Perl modules can be loaded, and
    # print its version number.
    my $set;
    my $perlModules = $this->_loadDEPENDENCIES();
    if (ref($perlModules)) {
        $set = $this->checkPerlModules( $perlModules );
    } else {
        $set = $this->ERROR($perlModules);
    }

    $block .= $this->setting("Perl modules",
                       CGI::start_table({width=>'100%'}).
                       $set.CGI::end_table());

    # All module checks done, OK to enable fatalsToBrowser
    import CGI::Carp qw( fatalsToBrowser );

    # PATH_INFO
    my $url = $TWiki::query->url();
    $block .= $this->setting(CGI::a({name=>'PATH_INFO'},'PATH_INFO'),
                             $TWiki::query->path_info().
              $this->NOTE(<<HERE
For a URL such as <strong>$url/foo/bar</strong>,
the correct PATH_INFO is <strong>/foo/bar</strong>, without any prefixed path
components. <a rel="nofollow" href="$url/foo/bar#PATH_INFO">
<strong>Click here to test this</strong></a>
- particularly if you are using mod_perl, Apache or IIS, or are using
a web hosting provider.
Look at the new path info here. It should be <strong>/foo/bar</strong>.
HERE
                  ));

    # mod_perl
    if( $TWiki::cfg{DETECTED}{UsingModPerl} ) {
        $n = "Used for this script";
    } else {
        $n = "Not used for this script";
    }
    $n .= $this->NOTE(
        'mod_perl is ', $TWiki::cfg{DETECTED}{ModPerlLoaded} ? '' : 'not',
        ' loaded into Apache' );
    if ( $TWiki::cfg{DETECTED}{ModPerlVersion} ) {
        $n .= $this->NOTE( 'mod_perl version ', $TWiki::cfg{DETECTED}{ModPerlVersion} );
    }

    # Check for a broken version of mod_perl 2.0
    if ( $TWiki::cfg{DETECTED}{UsingModPerl} && $TWiki::cfg{DETECTED}{ModPerlVersion} =~ /1\.99_?11/ ) {
        # Recommend mod_perl upgrade if using a mod_perl 2.0 version
        # with PATH_INFO bug (see Support.RegistryCookerBadFileDescriptor
        # and Bugs:Item82)
        $n .= $this->ERROR(<<HERE);
Version $TWiki::cfg{DETECTED}{ModPerlVersion} of mod_perl is known to have major bugs that prevent
its use with TWiki. 1.99_12 or higher is recommended.
HERE
    }
    $block .= $this->setting('mod_perl', $n);

    # Get web server's user and group info
    my $usr;
    eval {
        $usr = getlogin() || getpwuid($>) || '';
    };

    my $grp = '';
    eval {
        $grp = join(',', map { lc(getgrgid( $_ )) } split( ' ', $( ));
    };
    if( $@ ) {
        # Try to use Cygwin's 'id' command - may be on the path, since Cygwin
        # is probably installed to supply ls, egrep, etc - if it isn't, give
        # up.
        # Run command without stderr output, to avoid CGI giving error.
        # Get names of primary and other groups.
        $grp = lc(qx(sh -c '( id -un ; id -gn) 2>/dev/null' 2>nul ));
    }

    $block .= $this->setting(
        'CGI user', 'userid = <strong>'.$usr.'</strong> groups = <strong>'.
          $grp.'</strong>'.
            $this->NOTE(
                'Your CGI scripts are executing as this user.'));

    $block .= $this->setting(
        'Original PATH', $TWiki::cfg{DETECTED}{originalPath}.
          $this->NOTE(<<HERE));
This is the PATH value passed in from the web server to this
script - it is reset by TWiki scripts to the PATH below, and
is provided here for comparison purposes only.
HERE

    my $currentPath = $ENV{PATH} || '';     # As re-set earlier in this routine
    $block .= $this->setting("Current PATH", $currentPath,
              $this->NOTE(<<HERE
This is the actual PATH setting that will be used by Perl to run
programs. It is normally identical to {SafeEnvPath}, unless
that variable is empty, in which case this will be the webserver users
standard path..
HERE
                  ));

    return $this->foldableBlock(
        CGI::em( 'CGI Setup' ), '(read only) ',
        $block);
};

sub _checkBinDir {
    my $this = shift;
    my $dir = $ENV{SCRIPT_FILENAME} || '.';
    $dir =~ s(/+configure[^/]*$)();
    my $ext = $TWiki::cfg{ScriptSuffix} || '';
    my $errs = '';
    opendir(D, $dir) ||
      return $this->ERROR(<<HERE);
Cannot open '$dir' for read ($!) - check it exists, and that permissions are correct.
HERE
    foreach my $script (grep { -f "$dir/$_" && /^\w+(\.\w+)?$/ } readdir D) {
        next if( $ext && $script !~ /\.$ext$/ );
        if( $TWiki::cfg{OS} !~ /^Windows$/i &&
              $script !~ /\.cfg$/ &&
                !-x "$dir/$script" ) {
            $errs .= $this->WARN(<<HERE);
$script might not be an executable script - please check it (and its
permissions) manually.
HERE
        }
    }
    closedir(D);
    return $dir.CGI::br().$errs;
}

# The perl modules that are required by TWiki.
sub _loadDEPENDENCIES {
    my $this = shift;

    $FindBin::Bin =~ /^(.*)$/;
    my @dir = File::Spec->splitdir($1);
    pop(@dir);

    local $/ = "\n";
    push(@dir, 'tools');
    my $from = File::Spec->catfile(@dir, 'DEPENDENCIES');
    my $d;
    open($d, '<'.$from) || return 'Failed to load DEPENDENCIES: '.$!;
    my @perlModules;
    foreach my $line ( <$d> ) {
        next unless $line;
        my @row = split(/,\s*/, $line, 4);
        next unless (scalar(@row) == 4 && $row[2] eq 'cpan');
        my $ver = $row[1];
        $ver =~ s/[<>=]//g;
        my ($dispo,$usage) = $row[3] =~ /^\s*(\w+).?(.*)$/;
        push(@perlModules, {
            name => $row[0],
            usage => $usage,
            minimumVersion => $ver,
            disposition => lc($dispo)
           });
    }
    close($d);
    return \@perlModules;
}

1;
