#!/usr/bin/ruby
#
# Copyright © 2011, Lucas Nussbaum <lucas@debian.org>
# 
# 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 3 of the License, or
# (at your option) any later version.
# 
# 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.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

require 'gem2deb'
require 'gem2deb/dh_ruby'
require 'gem2deb/gem_installer'
require 'optparse'
require 'shellwords'
include Gem2Deb

if ENV['DH_RUBY']
  opts = Shellwords.split(ENV['DH_RUBY'])
  ARGV.unshift(*opts)
end

engine = Gem2Deb::DhRuby.new
action = nil

optparse = OptionParser.new do |opts|
  opts.banner = "Usage: dh_ruby [OPTIONS] ACTION"
  opts.separator "Options:"

  opts.on('-h', '--help', 'show help') do
    puts opts
    exit
  end

  opts.on('--gem-install', 'install files as a gem') do
    engine.installer_class = Gem2Deb::GemInstaller
  end

  opts.on('-v', '--version', 'show dh_ruby version') do
    puts "dh_ruby version #{Gem2Deb::VERSION}"
    exit
  end

  opts.on('--print-supported', 'prints supported Ruby versions') do
    Gem2Deb::SUPPORTED_RUBY_VERSIONS.keys.each do |v|
      puts v
    end
    exit
  end

  opts.separator "ACTION must be one of:"
  opts.on('--clean', 'debhelper clean helper') do
    action = :clean
  end

  opts.on('--configure', 'debhelper configure helper') do
    action = :configure
  end

  opts.on('--build', 'debhelper build helper') do
    action = :build
  end

  opts.on('--test', 'debhelper test helper') do
    action = :test
  end

  opts.on('--install', 'debhelper install helper') do
    action = :install
  end
end
optparse.parse!

if action.nil?
  puts "E: no action selected. You must pass one (and only one) of:"
  puts "   --install, --clean, --configure, --build, --test"
  puts optparse
  exit(1)
end

if action == :install
  engine.install(ARGV)
else
  engine.send(action)
end

__END__
=head1 NAME

dh_ruby - debhelper build system for Ruby software

=head1 SYNOPSIS


B<dh_ruby> [I<OPTIONS>]

=head1 DESCRIPTION

B<dh_ruby> is a Debhelper build system for Ruby software. It will
automatically build and install files contained in Ruby packages, trying to
work as close to Rubygems as possible but respecting Debian standards for Ruby
packages.

dh_ruby can automatically run your tests against all supported Ruby versions,
see the "FILES" section below.

See dh_ruby --help for details.

=head1 SOURCE PACKAGE LAYOUT

B<dh_ruby> supports two different source package styles: single-binary source
packages, and multi-binary source packages.

=head2 Single-binary layout

The default layout is the B<single-binary> layout. This is the layout used by
most Ruby packages upstream, i.e. Ruby code in I<lib>/, executable programs in
I<bin>/, etc. Packages imported from Rubygems using B<gem2deb(1)> will have
this layout.

When using this layout, B<dh_ruby> will install files (Ruby code,
executables, gemspecs) to the I<first binary package> listed in
I<debian/control>.

=head2 Multi-binary layout

B<gem2deb> version I<0.4.0> introduced support for the B<multi-binary>
layout. This layout should be used when you have a set of different Ruby
packages maintained upstream in a single VCS, and you decide that you
also want to maintain a single source package in Debian having the
different components as separate binary packages.

In this layout, the source package contains the separate components in
subdirectories where each of them will use the standard Ruby layout
(I<lib>/, I<bin>/, etc).

This layout does not support creating separate binary packages from the same
root directory. For those cases, see the documentation on
I<DH_RUBY_USE_DH_AUTO_INSTALL_DESTDIR> below.

To indicate that you want to use a multi-binary layout, we have to 1)
list your multiple binary packages in I<debian/control> as usual, and
add an extra-field called I<X-DhRuby-Root> to each binary package
stanza, indicating which directory has to be used as the root for that
binary package.

An example:

    Source: mymultibinarypackage
    [...]
    
    Package: ruby-foo
    X-DhRuby-Root: path/to/foo
    [...]
    
    Package: ruby-bar
    X-DhRuby-Root: path/to/bar

The corresponding source package should be layed out like this:

    foo/
      foo.gemspec
      lib/
        foo.rb
      bin/foo
    bar/
      bar.gemspec
      lib/
        bar.rb
      bin/
        bar

Important notes about multi-binary packages and the usage of
I<X-DhRuby-Root>:

=over

=item

If your package uses the multi-binary layout, it must include
`I<gem2deb> (>= 0.4.0~)` in I<Build-Depends>.

B<Version 0.4.0 had a bug in the support for native extensions> in
multi-binary packages, so if your package uses the multi-binary feature
and at least one of the sub-components has native extensions, you must
use `I<gem2deb> (>= 0.4.1~)` in I<Build-Depends> instead.

=item

The path indicated in I<X-DhRuby-Root>, as you have probably guessed by
now, must be relative to the root of the source package.

=item

If any binary package declares a I<X-DhRuby-Root> field, all other
binary packages that don't have one will be ignored by B<dh_ruby>.

=back

=head1 OPTIONS

=over

=item B<--clean>, B<--configure>, B<--build>, B<--test>, B<--install>

Commands called by debhelper at various steps of the build process.

=item B<--print-supported>

Prints the supported Ruby versions.

=item B<-h>, B<--help>

Displays B<dh_ruby> usage information.

=item B<-v>, B<--version>

Displays B<dh_ruby> version information.

=item B<--gem-install>

This option indicates that the build should use the B<gem> command to install
the files, instead of the homegrown installer. Native packages will be
installed to I</usr/lib/$ARCH/rubygems-integration/$RUBY_VERSION>, while pure
Ruby packages will be installed to I</usr/share/rubygems-integration/all>.

There is an internal include list of directories from the source package that need
to be installed, but we can't possibly know all possibilities: if a package
needs to install a directory that is not automatically installed, use
I<DH_RUBY_GEM_INSTALL_INCLUDE>. If you want to exclude a directory
from  being installed, use I<DH_RUBY_GEM_INSTALL_EXCLUDE>. Note that for using
those variables, you need to build depend on gem2deb (>= 1.6~).

=back

=head1 COMPATIBILITY LEVELS

dh_ruby reuses the L<B<debhelper>>(7) compatibility levels for introducing
behavior changes that might be backwards-incompatible.

=over

=item v14

This level is still open for development; use with caution.

Changes from v13 are:

Packages are built and tested when executing the B<build> target of
I<debian/rules>. The build is done as part of B<dh_auto_build>, and the tests
are run as part of B<dh_auto_test>. The installation into debian/ is performed
during the B<install> target, i.e.  during B<dh_auto_install>. This means that
you can intercept the build between these steps using targets such
B<execute_after_dh_auto_build>, B<override_dh_auto_build>,
B<override_dh_auto_test>, B<execute_before_dh_auto_install> etc.

=item v13

This is the recommended mode of operation.

This was the current compatibility level at the point where this mechanism was
introduced. So even packages with compatibility levels lower than 13 use this
mode.

In this this compatibility level, dh_ruby exhibits its classic behavior. In
particular, packages are built, installed and tested during the
B<dh_auto_install> phase of the build process, i.e. when dpkg-buildpackage is
invoking the B<install> target of I<debian/rules>.

=back

=head1 SUBSTITUTION VARIABLES

=over

=item I<${ruby:Depends}>

${ruby:Depends} will expand to the runtime dependencies of the package. This is
determined by taking the runtime dependencies from the Rubygems metadata, and
then mapping them to Debian package names.

The relevant packages must be installed during the package build for the
mapping to be successful (normally they should be hardcoded in the
Build-Depends: field).

=back

=head1 ENVIRONMENT VARIABLES

=over

=item I<DH_RUBY>

Use this variable to pass command line parameters to dh_ruby. For example in
debian/rules:

    export DH_RUBY = --gem-install

=item I<DH_RUBY_IGNORE_TESTS>

This is a space-separated list of tests that dh_ruby will ignore during package
build. The available test names are the names of all supported Ruby versions
(you can list them with `dh_ruby --print-supported`).

If set to "all", all tests will be ignored during the package build.

=item I<DH_RUBY_USE_DH_AUTO_INSTALL_DESTDIR>

If this variable is defined (to anything), dh_ruby will respect the directory
informed by dh_auto_install(1), usually I<debian/tmp>. By default, gem2deb will
install files to debian/I<package>, where I<package> is the first binary
package listed in debian/control.

This is useful for multi-binary source packages that don't conform to
the supported layout (i.e. separate subdirectories each with I<lib>/,
I<bin>/ etc). Using this, all files will be installed to I<debian/tmp>, and
you can them distribute them into separate binary packages by using
I<debian/$package.install> files or explicit shell calls in
I<debian/rules>.

Mixing I<DH_RUBY_USE_DH_AUTO_INSTALL_DESTDIR> and multi-binary layout is
not supported.

=item I<DH_RUBY_GEMSPEC>

Determines which file contain the gem specification with package metadata.  By
default, dh_ruby will read metadata from a .gemspec file in the root of source
package directory. You can use this variable to override that if you want to
provide custom metadata for the Debian package.

In the case there are more than one .gemspec in the source package root, you
will I<need> to use DH_RUBY_GEMSPEC to instruct dh_ruby about which one to use.

=item I<DH_RUBY_GEM_INSTALL_INCLUDE>.

When using --gem-install, this variable adds B<files> to the list of files that
need to be installed. Entries must be separated by spaces, and can be either
exact filenames, of glob expressions (e.g. I<*.txt>, I<foo/*>).

Directories cannot be added directly, only files. If you want to include an
entire directory, say I<foo>, use a glob expression like I<foo/*>.

Note that by default all top-level files are automatically excluded, except
I<VERSION*> which is used by some packages. If you need a top-level file to be
installed, you need to explicit list it as included.

=item I<DH_RUBY_GEM_INSTALL_EXCLUDE>.

When using --gem-install, this variable adds files to the list of files that
SHOULD NOT be installed. Entries must be separated by spaces, and must be
either specific filenames, or glob expressions (e.g. I<*.txt>).

Directories cannot be excluded directly. To exclude an entire directory,
use a glob expression such as I<foo/*>.

=back

=head1 FILES

=over

=item debian/I<ruby-test-files.yaml>, debian/I<ruby-tests.rake>, debian/I<ruby-tests.rb>

Theses files can be used to explicitly tell dh_ruby how to run the tests in your
package. When running the tests, dh_ruby will automatically set RUBYLIB to
include the appropriate directories where the package files were installed in
your package to make sure the tests use them instead of the files in the source
directory.

B<Your package can only contain at most one of these files.>

debian/I<ruby-test-files.yaml> must contain a YAML document with a list of test
files to be run. If the package metadata contains an explicit list of test
files, gem2deb(1) will automatically generate this file for you. Example from
ruby-mime-types:

  --- 
  - test/test_mime_type.rb
  - test/test_mime_types.rb

debian/I<ruby-tests.rake> can be used to run the tests with rake(1). You can
use anything you would use in a regular Rakefile, but you must define a default
task. gem2deb includes a utility test task that makes it easier for you by
creating a default task automatically. Example:

  require 'gem2deb/rake/testtask'
  Gem2Deb::Rake::TestTask.new do |t|
    t.test_files = FileList['test/*_test.rb']
  end

You can also use the equivalent RSpec task:

  require 'gem2deb/rake/spectask'
  Gem2Deb::Rake::RSpecTask.new do |spec|
    spec.pattern = './spec/**/*_spec.rb'
  end

If debian/I<ruby-tests.rb> exists, it will be run with each supported Ruby
version, and must finish with a exit status of I<0>, otherwise dh_ruby assumes
the tests failed. A simple example:

  require 'test/unit'
  require 'mypackage' # if 'mypackage.rb' or 'mypackage.so' was not installed properly, this will fail
  class MyPackageTest < Test::Unit::TestCase
    def test_features
      assert_equal 4, MyPackage.sum(2,2)
    end
  end

=item debian/I<dh_ruby.mk>

If this file is present, dh_ruby will call B<make> passing it as the makefile
during the build, in the I<clean>, I<build>, and I<install> steps, like this:

=over

=item clean: B<make -f debian/dh_ruby.mk clean>

=item build: B<make -f debian/dh_ruby.mk>

=item install: B<make -f debian/dh_ruby.mk install>

=back

If you want the upstream Makefile to be used, just make I<debian/dh_ruby.mk> a
symlink to I<../Makefile>.

=item debian/I<dh_ruby.rake>

If this file is present, dh_ruby will call B<rake> passing it as the rakefile
during the build, in the I<clean>, I<build>, and I<install> steps, like this:

=over

=item clean: B<rake -f debian/dh_ruby.rake clean>

=item build: B<rake -f debian/dh_ruby.rake>

=item install: B<rake -f debian/dh_ruby.rake install>

=back

If you want the upstream Rakefile to be used, just make I<debian/dh_ruby.rake> a
symlink to I<../Rakefile>.

=item debian/I<gemspec>

If this file exists, it will be used as the package gemspec, regardless of
I<metadata.yml> and any I<*.gemspec> that exists in the upstream source. Using
this is only advised on single-binary source packages, and the behavior of this
feature is undefined for multi-binary source packages (see B<SOURCE PACKAGE
LAYOUT> above).

If debian/I<gemspec> is a symlink, it will first be expanded, and then the
symlink target will be used as a gemspec.

Hint: for packages with multiple gemspec, you can have debian/I<gemspec> as a
symlink pointing to the one you want to use.

=back

=head1 SEE ALSO

L<B<gem2deb>>(1)

=head1 COPYRIGHT AND AUTHORS

Copyright (c) 2011, Lucas Nussbaum <lucas@debian.org>

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 3 of the License, or
(at your option) any later version.

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.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
