# 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 'ruby_debian_dev'

module Gem2Deb

  class << self
    attr_accessor :verbose
    def testing
      ENV['GEM2DEB_TESTING']
    end
    def testing=(v)
      ENV['GEM2DEB_TESTING'] = v.to_s
    end
  end

  class CommandFailed < Exception
  end

  include RubyDebianDev

  SUPPORTED_RUBY_VERSIONS.select! do |version, binary|
    # To help backporters without having to also backport the interpreters.
    File.exist?(binary)
  end

  RUBY_SHEBANG_CALL = '/usr/bin/ruby'

  BIN_DIR = '/usr/bin'

  RUBY_CODE_DIR = '/usr/lib/ruby/vendor_ruby'

  LIBDIR = File.expand_path(File.dirname(__FILE__))

  def run(*argv)
    puts(_format_cmdline(argv)) if Gem2Deb.verbose
    system(*argv)
    if $?.exitstatus != 0
      raise Gem2Deb::CommandFailed, _format_cmdline(argv)
    end
  end

  def run_ruby(ruby, *args)
    cmd = args.dup
    if LIBDIR != '/usr/lib/ruby/vendor_ruby'
      # only add LIBDIR to load path is not running the installed copy
      cmd.unshift("-I", LIBDIR)
    end
    cmd.unshift(ruby)
    maybe_crossbuild(ruby) do
      run(*cmd)
    end
  end

  def maybe_crossbuild(ruby)
    @crossbuild_options ||= {}
    @crossbuild_options[ruby] ||=
      begin
        if cross_building?
          version = IO.popen([ruby, "-e", "puts RbConfig::CONFIG['ruby_version']"]).read.strip
          {
            "RUBYLIB" => "/usr/lib/#{host_arch}/ruby-crossbuild/#{version}",
          }
        else
          {}
        end
      end
    saveenv = {}
    begin
      @crossbuild_options[ruby].each do |k, v|
        saveenv[k] = ENV[k]
        ENV[k] = v
      end
      yield
    ensure
      saveenv.each do |k,v|
        ENV[k] = v
      end
    end
  end

  def build_arch
    @build_arch ||= `dpkg-architecture -qDEB_BUILD_MULTIARCH`.strip
  end

  def host_arch
    @host_arch ||= `dpkg-architecture -qDEB_HOST_MULTIARCH`.strip
  end

  def host_arch_gnu
    @host_arch_gnu ||= `dpkg-architecture -qDEB_HOST_GNU_TYPE`.strip
  end

  def cross_building?
    build_arch != host_arch
  end

  def default_compiler(name)
    @default_compiler ||= {}
    @default_compiler[name] ||=
      if cross_building?
        "#{host_arch_gnu}-#{name}"
      else
        name
      end
  end

  def make_cmd
    flags = "-fdebug-prefix-map=#{root}=."
    cc = [ENV.fetch('CC', default_compiler("gcc")), flags].join(' ')
    cxx = [ENV.fetch('CXX', default_compiler("g++")), flags].join(' ')
    "make V=1 CC='#{cc}' CXX='#{cxx}'"
  end

  private

  def _format_cmdline(argv)
    argv.map { |a| a =~ /\s/ && a.inspect || a }.join(' ')
  end
end

Gem2Deb.verbose = true

require 'gem2deb/version'