#!/usr/bin/perl

=head1 NAME

dh_installdebconf - install files used by debconf in package build directories

=cut

use strict;
use warnings;
use Debian::Debhelper::Dh_Lib;

our $VERSION = DH_BUILTIN_VERSION;

=head1 SYNOPSIS

B<dh_installdebconf> [S<I<debhelper options>>] [B<-n>] [S<B<--> I<params>>]

=head1 DESCRIPTION

B<dh_installdebconf> is a debhelper program that is responsible for installing
files used by debconf into package build directories.

It also automatically generates the F<postrm> commands needed to interface
with debconf. The commands are added to the maintainer scripts by
B<dh_installdeb>. See L<dh_installdeb(1)> for an explanation of how that
works.

Note that if you use debconf, your package probably needs to depend on it
(it will be added to B<${misc:Depends}> by this program).

Note that for your config script to be called by B<dpkg>, your F<postinst>
needs to source debconf's confmodule. B<dh_installdebconf> does not
install this statement into the F<postinst> automatically as it is too
hard to do it right.

=head1 FILES

=over 4

=item debian/I<package>.config

This is the debconf F<config> script, and is installed into the F<DEBIAN>
directory in the package build directory.

Inside the script, the token B<#DEBHELPER#> is replaced with
shell script snippets generated by other debhelper commands.

=item debian/I<package>.templates

This is the debconf F<templates> file, and is installed into the F<DEBIAN>
directory in the package build directory.

=item F<debian/po/>

If this directory is present, this program will automatically use
L<po2debconf(1)> to generate merged templates
files that include the translations from there.

For this to work, your package should build-depend on F<po-debconf>.

=back

=head1 OPTIONS

=over 4

=item B<-n>, B<--no-scripts>

Do not modify F<postrm> script.

=item B<--> I<params>

Pass the params to B<po2debconf>.

=item B<-D>I<TOKEN=VALUE>, B<--define> I<TOKEN=VALUE>

Define tokens to be replaced inside the maintainer scripts when
it is generated.  Please note that the limitations described in
L</Limitations in token names> also applies to tokens defined
on the command line.  Invalid token names will trigger an error.

In the simple case, this parameter will cause B<< #I<TOKEN># >>
to be replaced by I<VALUE>.  If I<VALUE> starts with a literal
I<@>-sign, then I<VALUE> is expected to point to a file
containing the actual value to insert.

An explicit declared token with this parameter will replace built-in
tokens.

Test examples to aid with the understanding:

	cat >> debian/config <<EOF
	#SIMPLE#
	#FILEBASED#
	EOF
	echo -n "Complex value" > some-file
    dh_installdeb --define SIMPLE=direct --define FILEBASED=@some-file

In this example, B<#SIMPLE#> will expand to B<direct> and B<#FILEBASED#>
will expand to B<Complex value>.

It is also possible to set package-specific values for a given
token.  This is useful when B<dh_installdebconf> is acting on multiple
packages that need different values for the same token.  This is
done by prefixing the token name with B<< pkg.I<package-name>. >>.

This can be used as in the following example:

	cat >> debian/foo.config <<EOF
	# Script for #PACKAGE#
	#TOKEN#
	EOF
	cat >> debian/bar.config <<EOF
	# Script for #PACKAGE#
	#TOKEN#
	EOF
	cat >> debian/baz.config <<EOF
	# Script for #PACKAGE#
	#TOKEN#
	EOF
    dh_installdebconf -pfoo -pbar -pbaz  --define TOKEN=default --define pkg.bar.TOKEN=unique-bar-value \
      --define pkg.baz.TOKEN=unique-baz-value

In this example, B<#TOKEN#> will expand to B<default> in F<debian/foo.config>,
to B<unique-bar-value> in F<debian/bar.config> and to B<unique-baz-value>
in F<debian/baz.config>.

Note that the B<#pkg.*#> tokens will be visible in all scripts acted on.  E.g.
you can refer to B<#pkg.bar.TOKEN#> inside F<debian/foo.config> and it will
be replaced by B<unique-bar-value>.

=back

=head1 SUBSTITUTION IN MAINTAINER SCRIPTS

The B<dh_installdebconf> will automatically replace the following tokens
inside a provided maintainer script (if not replaced via B<-D>/B<--define>):

=over 4

=item #DEB_HOST_I<NAME>#, #DEB_BUILD_I<NAME>#, #DEB_TARGET_I<NAME>#

These tokens are replaced with the respective variable from
L<dpkg-architecture(1)>.  In almost all cases, you will want
use the B<< #DEB_HOST_I<NAME> >> variant in a script to ensure
you get the right value when cross-building.

On a best effort, tokens of this pattern that do not match
a variable in L<dpkg-architecture(1)> will be left as-is.

=item #ENV.I<NAME>#

These tokens of this form will be replaced with value of the
corresponding environment variable.  If the environment
variable is unset, the token is replaced with the empty
string.

Note that there are limits on which names can be used (see
L</Limitations in token names>).

=item #PACKAGE#

This token is by default replaced by the package name, which will contain
the concrete script.

=back

=head2 Limitations in token names

All tokens intended to be substituted must match the regex: #[A-Za-z0-9_.+]+#

Tokens that do not match that regex will be silently ignored if found in the
script template.  Invalid token names passed to B<-D> or B<--define> will
cause B<dh_installdebconf> to reject the command with an error in most cases.

=cut

my %PROVIDED_SUBST;

init(options => {
	'define|D=s%' => \%PROVIDED_SUBST,
});

my @extraparams;
if (defined($dh{U_PARAMS})) {
	@extraparams=@{$dh{U_PARAMS}};
}

# PROMISE: DH NOOP WITHOUT config templates cli-options()

foreach my $package (@{$dh{DOPACKAGES}}) {
	my $tmp=tmpdir($package);
	my $config=pkgfile($package,"config");
	my $templates=pkgfile($package,"templates");

	install_dir("$tmp/DEBIAN");

	if (! is_udeb($package)) {
		# Install debian scripts.
		my $package_subst = debhelper_script_per_package_subst($package, \%PROVIDED_SUBST);
		debhelper_script_subst($package, "config", $package_subst);
	}
	
	if ($templates ne '') {
		# Are there old-style translated templates?
		if (glob("$templates.??"), glob("$templates.??_??")) {
			warning "Ignoring debian/templates.ll files. Switch to po-debconf!";
		}

		umask(0022); # since I do a redirect below

		if (-d "debian/po") {
			complex_doit("po2debconf @extraparams $templates > $tmp/DEBIAN/templates");
		}
		else {
			install_file($templates,"$tmp/DEBIAN/templates");
		}
	}

	# I'm going with debconf 0.5 because it was the first
	# "modern" one. udebs just need cdebconf.
	my $debconfdep=is_udeb($package) ? "cdebconf-udeb" : "debconf (>= 0.5) | debconf-2.0";
	if ($config ne '' || $templates ne '') {
		addsubstvar($package, "misc:Depends", $debconfdep);
	}
	
	if (($config ne '' || $templates ne '') && ! $dh{NOSCRIPTS}) {
		autoscript($package,"postrm","postrm-debconf");
	}
}

=head1 SEE ALSO

L<debhelper(7)>

This program is a part of debhelper.

=head1 AUTHOR

Joey Hess <joeyh@debian.org>

=cut