#!/usr/bin/perl -w

=head1 NAME

dh_pdl - calculates pdl dependencies

=cut

use strict;
use Config;
use File::Find;
use Debian::Debhelper::Dh_Lib;
use PDL::Config::Debian;

=head1 SYNOPSIS

B<dh_pdl> [S<I<debhelper options>>] [B<-d>] [S<I<library dirs ...>>]

=head1 DESCRIPTION

dh_pdl is a debhelper program that is responsible for generating
the ${pdl:Depends} substitutions and adding them to substvars files.

The program will look at perl scripts and modules in your package,
and will use this information to generate a dependency on pdl or
pdlapi. The dependency will be substituted into your package's control
file wherever you place the token "${pdl:Depends}".

=head1 OPTIONS

=over 4

=item B<-V>

By default, scripts and architecture independent modules don't depend
on any specific version of pdl.  The -V option causes the current
version of the pdl package to be specified.

=item I<library dirs>

If your package installs perl modules in non-standard
directories, you can make dh_perl check those directories by passing their
names on the command line. It will only check the vendorlib and vendorarch
directories by default.

=back

=head1 CONFORMS TO

Debian policy, version 3.8.3

=cut

init();

my $vendorlib = substr $Config{vendorlib}, 1;
my $vendorarch = substr $Config{vendorarch}, 1;

# Cleaning the paths given on the command line
foreach (@ARGV) {
	s#/$##;
	s#^/##;
}

my $pdl = 'pdl';
my $version;

# dependency types
use constant PROGRAM   => 1;
use constant PM_MODULE => 2;
use constant XS_MODULE => 4;

foreach my $package (@{$dh{DOPACKAGES}}) {
	my $tmp=tmpdir($package);

	# Check also for alternate locations given on the command line
	my @dirs = grep -d, map "$tmp/$_", $vendorlib, $vendorarch, @ARGV;

	# Look for perl modules and check where they are installed
	my $deps = 0;
	find sub {
		return unless -f;
		$deps |= PM_MODULE if /\.pm$/;
		$deps |= XS_MODULE if /\.so$/;
	}, @dirs if @dirs;

	# find scripts
	find sub {
		return unless -f and (-x or /\.pl$/);
		return if $File::Find::dir=~/\/usr\/share\/doc\//;
		
		local *F;
		return unless open F, $_;
		if (read F, local $_, 32 and m%^#!\s*(/usr/bin/perl|/usr/bin/env\s+perl)\s%) {
			$deps |= PROGRAM;
		}
		close F;
	}, $tmp;

	if ($deps) {
		my $version="";
		if ($deps & XS_MODULE or $dh{V_FLAG_SET}) {
			($version) = `dpkg -s $pdl` =~ /^Version:\s*(\S+)/m
				unless $version;
			$version = ">= $version";
		}
		
		addsubstvar($package, "pdl:Depends", $pdl, $version);

		# add pdlapi-<ver> for XS modules
		addsubstvar($package, "pdl:Depends",
			"pdlapi-$PDL::Config::Debian::pdl_core_version")
			if $deps & XS_MODULE;
	}
}

=head1 SEE ALSO

L<debhelper(7)>

=head1 AUTHOR

Henning Glawe <glaweh@debian.org>

Based on dh_perl by Brendan O'Dea <bod@debian.org>

=cut