package Module::Build::Platform::VMS;

use strict;
use vars qw($VERSION);
$VERSION = '0.2808_01';
$VERSION = eval $VERSION;
use Module::Build::Base;

use vars qw(@ISA);
@ISA = qw(Module::Build::Base);



=head1 NAME

Module::Build::Platform::VMS - Builder class for VMS platforms

=head1 DESCRIPTION

This module inherits from C<Module::Build::Base> and alters a few
minor details of its functionality.  Please see L<Module::Build> for
the general docs.

=head2 Overridden Methods

=over 4

=item _set_defaults

Change $self->{build_script} to 'Build.com' so @Build works.

=cut

sub _set_defaults {
    my $self = shift;
    $self->SUPER::_set_defaults(@_);

    $self->{properties}{build_script} = 'Build.com';
}


=item cull_args

'@Build foo' on VMS will not preserve the case of 'foo'.  Rather than forcing
people to write '@Build "foo"' we'll dispatch case-insensitively.

=cut

sub cull_args {
    my $self = shift;
    my($action, $args) = $self->SUPER::cull_args(@_);
    my @possible_actions = grep { lc $_ eq lc $action } $self->known_actions;

    die "Ambiguous action '$action'.  Could be one of @possible_actions"
        if @possible_actions > 1;

    return ($possible_actions[0], $args);
}


=item manpage_separator

Use '__' instead of '::'.

=cut

sub manpage_separator {
    return '__';
}


=item prefixify

Prefixify taking into account VMS' filepath syntax.

=cut

# Translated from ExtUtils::MM_VMS::prefixify()
sub _prefixify {
    my($self, $path, $sprefix, $type) = @_;
    my $rprefix = $self->prefix;

    $self->log_verbose("  prefixify $path from $sprefix to $rprefix\n");

    # Translate $(PERLPREFIX) to a real path.
    $rprefix = VMS::Filespec::vmspath($rprefix) if $rprefix;
    $sprefix = VMS::Filespec::vmspath($sprefix) if $sprefix;

    $self->log_verbose("  rprefix translated to $rprefix\n".
                       "  sprefix translated to $sprefix\n");

    if( length $path == 0 ) {
        $self->log_verbose("  no path to prefixify.\n")
    }
    elsif( !File::Spec->file_name_is_absolute($path) ) {
        $self->log_verbose("    path is relative, not prefixifying.\n");
    }
    elsif( $sprefix eq $rprefix ) {
        $self->log_verbose("  no new prefix.\n");
    }
    else {
        my($path_vol, $path_dirs) = File::Spec->splitpath( $path );
	my $vms_prefix = $self->config('vms_prefix');
        if( $path_vol eq $vms_prefix.':' ) {
            $self->log_verbose("  $vms_prefix: seen\n");

            $path_dirs =~ s{^\[}{\[.} unless $path_dirs =~ m{^\[\.};
            $path = $self->_catprefix($rprefix, $path_dirs);
        }
        else {
            $self->log_verbose("    cannot prefixify.\n");
	    return $self->prefix_relpaths($self->installdirs, $type);
        }
    }

    $self->log_verbose("    now $path\n");

    return $path;
}

=item _quote_args

Command-line arguments (but not the command itself) must be quoted
to ensure case preservation.

=cut

sub _quote_args {
  # Returns a string that can become [part of] a command line with
  # proper quoting so that the subprocess sees this same list of args,
  # or if we get a single arg that is an array reference, quote the
  # elements of it and return the reference.
  my ($self, @args) = @_;
  my $got_arrayref = (scalar(@args) == 1 
                      && UNIVERSAL::isa($args[0], 'ARRAY')) 
                   ? 1 
                   : 0;

  map { $_ = q(").$_.q(") if !/^\"/ && length($_) > 0 }
     ($got_arrayref ? @{$args[0]} 
                    : @args
     );

  return $got_arrayref ? $args[0] 
                       : join(' ', @args);
}

=item have_forkpipe

There is no native fork(), so some constructs depending on it are not
available.

=cut

sub have_forkpipe { 0 }

=item _backticks

Override to ensure that we quote the arguments but not the command.

=cut

sub _backticks {
  # The command must not be quoted but the arguments to it must be.
  my ($self, @cmd) = @_;
  my $cmd = shift @cmd;
  my $args = $self->_quote_args(@cmd);
  return `$cmd $args`;
}

=item do_system

Override to ensure that we quote the arguments but not the command.

=cut

sub do_system {
  # The command must not be quoted but the arguments to it must be.
  my ($self, @cmd) = @_;
  $self->log_info("@cmd\n");
  my $cmd = shift @cmd;
  my $args = $self->_quote_args(@cmd);
  return !system("$cmd $args");
}

=item _infer_xs_spec

Inherit the standard version but tweak the library file name to be 
something Dynaloader can find.

=cut

sub _infer_xs_spec {
  my $self = shift;
  my $file = shift;

  my $spec = $self->SUPER::_infer_xs_spec($file);

  # Need to create with the same name as DynaLoader will load with.
  if (defined &DynaLoader::mod2fname) {
    my $file = $$spec{module_name} . '.' . $self->{config}->get('dlext');
    $file =~ tr/:/_/;
    $file = DynaLoader::mod2fname([$file]);
    $$spec{lib_file} = File::Spec->catfile($$spec{archdir}, $file);
  }

  return $spec;
}

=item rscan_dir

Inherit the standard version but remove dots at end of name.  This may not be 
necessary if File::Find has been fixed or DECC$FILENAME_UNIX_REPORT is in effect.

=cut

sub rscan_dir {
  my ($self, $dir, $pattern) = @_;

  my $result = $self->SUPER::rscan_dir( $dir, $pattern );

  for my $file (@$result) { $file =~ s/\.$//; }
  return $result;
}

=item dist_dir

Inherit the standard version but replace embedded dots with underscores because 
a dot is the directory delimiter on VMS.

=cut

sub dist_dir {
  my $self = shift;

  my $dist_dir = $self->SUPER::dist_dir;
  $dist_dir =~ s/\./_/g;
  return $dist_dir;
}

=item man3page_name

Inherit the standard version but chop the extra manpage delimiter off the front if 
there is one.  The VMS version of splitdir('[.foo]') returns '', 'foo'.

=cut

sub man3page_name {
  my $self = shift;

  my $mpname = $self->SUPER::man3page_name( shift );
  my $sep = $self->manpage_separator;
  $mpname =~ s/^$sep//;
  return $mpname;
}

=item expand_test_dir

Inherit the standard version but relativize the paths as the native glob() doesn't
do that for us.

=cut

sub expand_test_dir {
  my ($self, $dir) = @_;

  my @reldirs = $self->SUPER::expand_test_dir( $dir );

  for my $eachdir (@reldirs) {
    my ($v,$d,$f) = File::Spec->splitpath( $eachdir );
    my $reldir = File::Spec->abs2rel( File::Spec->catpath( $v, $d, '' ) );
    $eachdir = File::Spec->catfile( $reldir, $f );
  }
  return @reldirs;
}

=item _detildefy

The home-grown glob() does not currently handle tildes, so provide limited support
here.  Expect only UNIX format file specifications for now.

=cut

sub _detildefy {
    my ($self, $arg) = @_;

    # Apparently double ~ are not translated.
    return $arg if ($arg =~ /^~~/);

    # Apparently ~ followed by whitespace are not translated.
    return $arg if ($arg =~ /^~ /);

    if ($arg =~ /^~/) {
        my $spec = $arg;

        # Remove the tilde
        $spec =~ s/^~//;

        # Remove any slash folloing the tilde if present.
        $spec =~ s#^/##;

        # break up the paths for the merge
        my $home = VMS::Filespec::unixify($ENV{HOME});

        # Trivial case of just ~ by it self
        if ($spec eq '') {
            return $home;
        }

        my ($hvol, $hdir, $hfile) = File::Spec::Unix->splitpath($home);
        if ($hdir eq '') {
             # Someone has tampered with $ENV{HOME}
             # So hfile is probably the directory since this should be
             # a path.
             $hdir = $hfile;
        }

        my ($vol, $dir, $file) = File::Spec::Unix->splitpath($spec);

        my @hdirs = File::Spec::Unix->splitdir($hdir);
        my @dirs = File::Spec::Unix->splitdir($dir);

        my $newdirs;

        # Two cases of tilde handling
        if ($arg =~ m#^~/#) {

            # Simple case, just merge together
            $newdirs = File::Spec::Unix->catdir(@hdirs, @dirs);

        } else {

            # Complex case, need to add an updir - No delimiters
            my @backup = File::Spec::Unix->splitdir(File::Spec::Unix->updir);

            $newdirs = File::Spec::Unix->catdir(@hdirs, @backup, @dirs);

        }
        
        # Now put the two cases back together
        $arg = File::Spec::Unix->catpath($hvol, $newdirs, $file);

    } else {
        return $arg;
    }

}

=item find_perl_interpreter

On VMS, $^X returns the fully qualified absolute path including version
number.  It's logically impossible to improve on it for getting the perl
we're currently running, and attempting to manipulate it is usually
lossy.

=cut

sub find_perl_interpreter { return $^X; }

=back

=head1 AUTHOR

Michael G Schwern <schwern@pobox.com>
Ken Williams <kwilliams@cpan.org>
Craig A. Berry <craigberry@mac.com>

=head1 SEE ALSO

perl(1), Module::Build(3), ExtUtils::MakeMaker(3)

=cut

1;
__END__