#!/usr/bin/perl

=encoding UTF-8

=head1 NAME

dh_installdocs - install documentation into package build directories

=cut

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

our $VERSION = DH_BUILTIN_VERSION;

=head1 SYNOPSIS

B<dh_installdocs> [S<I<debhelper options>>] [B<-A>] [B<-X>I<item>] [S<I<file> ...>]

=head1 DESCRIPTION

B<dh_installdocs> is a debhelper program that is responsible for installing
documentation into F<usr/share/doc/package> in package build directories.

In compat 10 and earlier, L<dh_install(1)> may be a better tool for handling
the upstream documentation, when upstream's own build system installs all the desired documentation
correctly.  In this case, B<dh_installdocs> is still useful for installing
packaging related documentation (e.g. the F<debian/copyright> file).

From debhelper compatibility level 11 on, B<dh_install> will fall back to
looking in F<debian/tmp> for files, if it does not find them in the current
directory (or wherever you've told it to look using B<--sourcedir>).

In compat 11 and later, B<dh_installdocs> offers many of the features that
L<dh_install(1)> also has.  Furthermore, B<dh_installdocs> also supports
the B<nodoc> build profile to exclude documentation (regardless of compat
level).

=head1 FILES

=over 4

=item debian/I<package>.docs

List documentation files to be installed into I<package>.

Supports substitution variables in compat 13 and later as
documented in L<debhelper(7)>.

=item F<debian/copyright>

The copyright file is installed into all packages, unless a more
specific copyright file is available.

=item debian/I<package>.copyright

=item debian/I<package>.README.Debian

=item debian/I<package>.TODO

Each of these files is automatically installed if present for a
I<package>.

=item F<debian/README.Debian>

=item F<debian/TODO>

These files are installed into the first binary package listed in
debian/control.

Note that F<README.debian> files are also installed as F<README.Debian>,
and F<TODO> files will be installed as F<TODO.Debian> in non-native packages.

=item debian/I<package>.doc-base

Installed as doc-base control files. Note that the doc-id will be
determined from the B<Document:> entry in the doc-base control file in
question. In the event that multiple doc-base files in a single source
package share the same doc-id, they will be installed to
usr/share/doc-base/package instead of usr/share/doc-base/doc-id.

=item debian/I<package>.doc-base.*

If your package needs to register more than one document, you need
multiple doc-base files, and can name them like this. In the event
that multiple doc-base files of this style in a single source package
share the same doc-id, they will be installed to
usr/share/doc-base/package-* instead of usr/share/doc-base/doc-id.

=back

=head1 OPTIONS

=over 4

=item B<-A>, B<--all>

Install all files specified by command line parameters in ALL packages
acted on.

=item B<-X>I<item>, B<--exclude=>I<item>

Exclude files that contain I<item> anywhere in their filename from
being installed. Note that this includes doc-base files.

=item B<--sourcedir=>I<dir>

Look in the specified directory for files to be installed.  This option
requires compat 11 or later (it is silently ignored in compat 10 or earlier).

Note that this is not the same as the B<--sourcedirectory> option used
by the B<dh_auto_>I<*> commands. You rarely need to use this option, since
B<dh_installman> automatically looks for files in F<debian/tmp> in debhelper
compatibility level 11 and above.

=item B<--doc-main-package=>I<main-package>

Set the main package for a documentation package.  This is used to
install the documentation of the documentation package in F<<
/usr/share/doc/I<main-package> >> as recommended by the Debian policy
manual 3.9.7 in §12.3.

In compat 11 (or later), this option is only useful if debhelper's
auto-detection of the main package is wrong.  The option can also be
used to silence a warning from debhelper when the auto-detection fails
but the default happens to be correct.

This option cannot be used when B<dh_installdocs> is instructed to act
on multiple packages.  If you need this option, you will generally
need to combine it with B<-p> to ensure exactly one package is acted
on.

Please keep in mind that some documentation (the copyright file,
README.Debian, etc.) will be unaffected by this option.

=item B<--link-doc=>I<package>

Make the documentation directory of all packages acted on be a symlink to
the documentation directory of I<package>. This has no effect when acting on
I<package> itself, or if the documentation directory to be created already
exists when B<dh_installdocs> is run. To comply with policy, I<package> must
be a binary package that comes from the same source package.

debhelper will try to avoid installing files into linked documentation
directories that would cause conflicts with the linked package. The B<-A>
option will have no effect on packages with linked documentation
directories, and F<copyright>, F<changelog>, F<README.Debian>, and F<TODO> files will
not be installed.

(An older method to accomplish the same thing, which is still supported,
is to make the documentation directory of a package be a dangling symlink,
before calling B<dh_installdocs>.)

Please note that this option only applies to the documentation
directory for the package itself.  When the package ships
documentation for another package (e.g. see B<--doc-main-package>), it
will not use a symlink for the documentation of the other package.


B<CAVEAT 1>: If a previous version of the package was built without this
option and is now built with it (or vice-versa), it requires a "dir to
symlink" (or "symlink to dir") migration.  Since debhelper has no
knowledge of previous versions, you have to enable this migration
itself.

This can be done by providing a "debian/I<package>.maintscript" file
and using L<dh_installdeb(1)> to provide the relevant maintainer
script snippets.

B<CAVEAT 2>: The use of B<--link-doc> should only be done when the
packages have same "architecture" type.  A link from an architecture
independent package to an architecture dependent package (or vice
versa) will not work.  Since compat 10, debhelper will actively reject
unsupported combinations.

=item I<file> ...

Install these files as documentation into the first package acted on. (Or
in all packages if B<-A> is specified).

=back

=head1 EXAMPLES

This is an example of a F<debian/package.docs> file:

  README
  TODO
  debian/notes-for-maintainers.txt
  docs/manual.txt
  docs/manual.pdf
  docs/manual-html/

=head1 NOTES

Note that B<dh_installdocs> will happily copy entire directory hierarchies if
you ask it to (similar to B<cp -a>). If it is asked to install a
directory, it will install the complete contents of the directory.

=cut

my %docdir_created;
# Create documentation directories on demand. This allows us to use dangling
# symlinks for linked documentation directories unless additional files need
# to be installed.
sub ensure_docdir {
	my $package=shift;
	return if $docdir_created{$package};
	my $tmp=tmpdir($package);

	my $target;
	if ($dh{LINK_DOC} && $dh{LINK_DOC} ne $package) {
		$target="$tmp/usr/share/doc/$dh{LINK_DOC}";
	}
	else {
		$target="$tmp/usr/share/doc/$package";
	}

	# If this is a symlink, leave it alone.
	if (! -d $target && ! -l $target) {
		install_dir($target);
	}
	$docdir_created{$package}=1;
}

init(options => {
	"link-doc=s" => \$dh{LINK_DOC},
	"sourcedir=s" => \$dh{SOURCEDIR},
	'doc-main-package=s' => \$dh{DOC_MAIN_PACKAGE},
});

my $called_getpackages = 0;
my $default_error_handler = compat(10) ? \&glob_expand_error_handler_reject_nomagic_warn_discard : \&glob_expand_error_handler_reject;
my $nodocs = is_build_profile_active('nodoc') || get_buildoption('nodoc') ? 1 : 0;
# We cannot assume documentation is built under nodoc, but if it is we must flag it as handled
# or dh_missing might make noise.
$default_error_handler = \&glob_expand_error_handler_silently_ignore if $nodocs;

if (@{$dh{DOPACKAGES}} > 1 and $dh{DOC_MAIN_PACKAGE}) {
	error('--doc-main-package should be used with -p<doc-pkg>');
}

if ($dh{DOC_MAIN_PACKAGE}) {
	assert_opt_is_known_package($dh{DOC_MAIN_PACKAGE}, '--doc-main-package');
}

foreach my $package (getpackages()) {
	next if is_udeb($package);
	
	my $tmp=tmpdir($package);
	my $file=pkgfile($package,"docs");
	my $link_doc=($dh{LINK_DOC} && $dh{LINK_DOC} ne $package);
	my $skip_install = process_pkg($package) ? 0 : 1;
	my @search_dirs = ('.');
	my $error_handler = $skip_install ? \&glob_expand_error_handler_silently_ignore : $default_error_handler;
	@search_dirs = ($dh{SOURCEDIR} // '.', default_sourcedir($package)) if not compat(10);

	if (not $skip_install) {
		if ($link_doc) {
			getpackages('both') unless $called_getpackages++;

			if (package_binary_arch($package) ne package_binary_arch($dh{LINK_DOC})) {
				if (compat(9)) {
					warning("WARNING: --link-doc between architecture all and not all packages breaks binNMUs");
				} else {
					error("--link-doc not allowed between ${package} and $dh{LINK_DOC} (one is arch:all and the other not)");
				}
			}
			# Make sure that the parent directory exists.
			if (!-d "$tmp/usr/share/doc" && !-l "$tmp/usr/share/doc") {
				install_dir("$tmp/usr/share/doc");
			}
			# Create symlink to another documentation directory if
			# necessary.
			if (!-d "$tmp/usr/share/doc/$package" &&
				!-l "$tmp/usr/share/doc/$package") {
				make_symlink_raw_target($dh{LINK_DOC}, "$tmp/usr/share/doc/$package");
				# Policy says that if you make your documentation
				# directory a symlink, then you have to depend on
				# the target.
				addsubstvar($package, 'misc:Depends', "$dh{LINK_DOC} (= \${binary:Version})");
			}
		} else {
			ensure_docdir($package);
		}
	}

	my @docs;

	if ($file) {
		@docs = filearray($file, \@search_dirs, $error_handler);
	}

	if (($package eq $dh{FIRSTPACKAGE} || ($dh{PARAMS_ALL} && !$link_doc)) && @ARGV) {
		push @docs, @ARGV;
	}

	log_installed_files($package, @docs);

	next if $skip_install;

	if (not $nodocs and @docs) {
		my $exclude = ' -and ! -empty';
		my $target_package = compute_doc_main_package($package);
		if (not defined($target_package)) {
			warning("Cannot auto-detect main package for ${package}.  If the default is wrong, please use --doc-main-package");
			$target_package = $package;
		} elsif ($dh{PARAMS_ALL} and $package ne $target_package and not $dh{DOC_MAIN_PACKAGE}) {
			warning("Not using auto-detected $target_package as main doc package for $package: With -A/--all, this would cause file-conflicts.");
			$target_package = $package;
		}
		if ($dh{EXCLUDE_FIND}) {
			$exclude .= ' -and ! \( '.$dh{EXCLUDE_FIND}.' \)';
		}
		my $target_dir = "${tmp}/usr/share/doc/${target_package}";
		install_dir($target_dir) unless -l $target_dir;

		foreach my $doc (@docs) {
			next if excludefile($doc);
			next if -f $doc && ! -s _; # ignore empty files
			ensure_docdir($package);
			if (-d $doc && length $exclude) {
				my $basename = basename($doc);
				my $dir = ($basename eq '.') ? $doc : "$doc/..";
				my $pwd=`pwd`;
				chomp $pwd;
				# Gracefully handling tmpdir being absolute (-P/...)
				my $docdir = $target_dir =~ m{^/} ? $target_dir : "${pwd}/${target_dir}";
				complex_doit("cd '$dir' && " .
							 "find '$basename' \\( -type f -or -type l \\)$exclude -print0 | LC_ALL=C sort -z | " .
							 "xargs -0 -I {} cp --reflink=auto --parents -dp {} $docdir");
			}
			else {
				doit("cp", '--reflink=auto', "-a", $doc, $target_dir);
			}
		}
		doit("chown","-R","0:0","$tmp/usr/share/doc") if should_use_root();
		doit("chmod","-R","u+rw,go=rX","$tmp/usr/share/doc");
	}

	# .Debian is correct, according to policy, but I'm easy.
	my $readme_debian=pkgfile($package,'README.Debian');
	if (! $readme_debian) {
		$readme_debian=pkgfile($package,'README.debian');
	}
	if (! $link_doc && $readme_debian && ! excludefile($readme_debian)) {
		ensure_docdir($package);
		install_file($readme_debian,
					 "$tmp/usr/share/doc/$package/README.Debian");
	}

	my $todo=pkgfile($package,'TODO');
	if (! $link_doc && $todo && ! excludefile($todo)) {
		ensure_docdir($package);
		if (isnative($package)) {
			install_file($todo, "$tmp/usr/share/doc/$package/TODO");
		}
		else {
			install_file($todo,
				"$tmp/usr/share/doc/$package/TODO.Debian");
		}
	}

	# If the "directory" is a dangling symlink, then don't install
	# the copyright file. This is useful for multibinary packages 
	# that share a doc directory.
	if (! $link_doc && (! -l "$tmp/usr/share/doc/$package" || -d "$tmp/usr/share/doc/$package")) {
		# Support debian/package.copyright, but if not present, fall
		# back on debian/copyright for all packages, not just the 
		# main binary package.
		my $copyright=pkgfile($package,'copyright');
		if (! $copyright && -e "debian/copyright") {
			$copyright="debian/copyright";
		}
		if ($copyright && ! excludefile($copyright)) {
			ensure_docdir($package);
			install_file($copyright,
				"$tmp/usr/share/doc/$package/copyright");
		}
	}

	next if $nodocs;

	# Handle doc-base files. There are two filename formats, the usual
	# plus an extended format (debian/package.*).
	my %doc_ids;
	
	opendir(DEB,"debian/") || error("can't read debian directory: $!");
	# If this is the main package, we need to handle unprefixed filenames.
	# For all packages, we must support both the usual filename format plus
	# that format with a period an something appended.
	my $regexp="\Q$package\E\.";
	if ($package eq $dh{MAINPACKAGE}) {
		$regexp="(|$regexp)";
	}
	foreach my $fn (grep {/^${regexp}doc-base(\..*)?$/} readdir(DEB)) {
		# .EX are example files, generated by eg, dh-make
		next if $fn=~/\.EX$/;
		next if excludefile($fn);
		# Parse the file to get the doc id.
		open(my $fd, '<', "debian/$fn") || die "Cannot read debian/$fn.";
		while (<$fd>) {
			s/\s*$//;
			if (/^Document\s*:\s*(.*)/) {
				$doc_ids{$fn}=$1;
				last;
			}
		}
		if (! exists $doc_ids{$fn}) {
			warning("Could not parse $fn for doc-base Document id; skipping");
		}
		close($fd);
	}
	closedir(DEB);
	
	if (%doc_ids) {
		install_dir("$tmp/usr/share/doc-base/");
	}
	# check for duplicate document ids
	my %used_doc_ids;
	for my $fn (keys %doc_ids) {
		$used_doc_ids{$doc_ids{$fn}}++;
	}
	foreach my $fn (keys %doc_ids) {
		# if this document ID is duplicated, we will install
		# to usr/share/doc-base/packagename instead of
		# usr/share/doc-base/doc_id. To allow for multiple
		# conflicting doc-bases in a single package, we will
		# install to usr/share/doc-base/packagename-extrabits
		# if the doc-base file is
		# packagename.doc-base.extrabits
		if ($used_doc_ids{$doc_ids{$fn}} > 1) {
			my $fn_no_docbase = $fn;
			$fn_no_docbase =~ s/\.doc-base(?:\.(.*))?/
			    if (defined $1 and length $1) {"-$1"} else {''}/xe;
			install_file("debian/$fn",
						 "$tmp/usr/share/doc-base/$fn_no_docbase");
		}
		else {
			install_file("debian/$fn",
						 "$tmp/usr/share/doc-base/$doc_ids{$fn}");
		}
	}
}

=head1 SEE ALSO

L<debhelper(7)>

This program is a part of debhelper.

=head1 AUTHOR

Joey Hess <joeyh@debian.org>

=cut