class Bundler::Standalone

def bundler_path
  Bundler.root.join(Bundler.settings[:path], "bundler")
end

def gem_path(path, spec)
  full_path = Pathname.new(path).absolute? ? path : File.join(spec.full_gem_path, path)
  Pathname.new(full_path).relative_path_from(Bundler.root.join(bundler_path)).to_s
rescue TypeError
  error_message = "#{spec.name} #{spec.version} has an invalid gemspec"
  raise Gem::InvalidSpecificationException.new(error_message)
end

def generate
  SharedHelpers.filesystem_access(bundler_path) do |p|
    FileUtils.mkdir_p(p)
  end
  File.open File.join(bundler_path, "setup.rb"), "w" do |file|
    file.puts "require 'rbconfig'"
    file.puts "# ruby 1.8.7 doesn't define RUBY_ENGINE"
    file.puts "ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : 'ruby'"
    file.puts "ruby_version = RbConfig::CONFIG[\"ruby_version\"]"
    file.puts "path = File.expand_path('..', __FILE__)"
    paths.each do |path|
      file.puts %($:.unshift "\#{path}/#{path}")
    end
  end
end

def initialize(groups, definition)
  @specs = groups.empty? ? definition.requested_specs : definition.specs_for(groups.map(&:to_sym))
end

def paths
  @specs.map do |spec|
    next if spec.name == "bundler"
    Array(spec.require_paths).map do |path|
      gem_path(path, spec).sub(version_dir, '#{ruby_engine}/#{ruby_version}')
      # This is a static string intentionally. It's interpolated at a later time.
    end
  end.flatten
end

def version_dir
  "#{Bundler::RubyVersion.system.engine}/#{RbConfig::CONFIG["ruby_version"]}"
end