require 'support/config'
require 'etc'
require 'yaml'
 
shared_examples_for "a spawner that supports lowering of privileges" do
  before :each do
    @stub = setup_rails_stub('foobar')
    @environment_rb = @stub.environment_rb
    @original_uid = File.stat(@environment_rb).uid
    File.append(@environment_rb, %q{
      require 'yaml'
      info = {
        :username => `whoami`.strip,
        :user_id  => `id -u`.strip.to_i,
        :group_id => `id -g`.strip.to_i,
        :groups   => `groups "#{`whoami`.strip}"`.strip,
        :home     => ENV['HOME']
      }
      File.open("#{RAILS_ROOT}/dump.yml", 'w') do |f|
        YAML::dump(info, f)
      end
    })
  end
  
  after :each do
    @stub.destroy
  end
  
  it "lowers its privileges to the owner of environment.rb" do
    File.chown(uid_for('normal_user_1'), nil, @environment_rb)
    spawn_stub_application do |app|
      read_dumped_info[:username].should == CONFIG['normal_user_1']
    end
  end
  
  it "switches the group to environment.rb's owner's primary group, after lowering privileges" do
    File.chown(uid_for('normal_user_1'), nil, @environment_rb)
    spawn_stub_application do |app|
      expected_gid = Etc.getpwnam(CONFIG['normal_user_1']).gid
      read_dumped_info[:group_id].should == expected_gid
    end
  end
  
  it "switches supplementary groups to environment.rb's owner's default supplementary groups" do
    File.chown(uid_for('normal_user_1'), nil, @environment_rb)
    spawn_stub_application do |app|
      default_groups = `groups "#{CONFIG['normal_user_1']}"`.strip
      read_dumped_info[:groups].should == default_groups
    end
  end
  
  it "lowers its privileges to 'lowest_user' if environment.rb is owned by root" do
    File.chown(ApplicationSpawner::ROOT_UID, nil, @environment_rb)
    spawn_stub_application do |app|
      read_dumped_info[:username].should == CONFIG['lowest_user']
    end
  end
  
  it "lowers its privileges to 'lowest_user' if environment.rb is owned by a nonexistant user" do
    File.chown(CONFIG['nonexistant_uid'], nil, @environment_rb)
    spawn_stub_application do |app|
      read_dumped_info[:username].should == CONFIG['lowest_user']
    end
  end
  
  it "doesn't switch user if environment.rb is owned by a nonexistant user, and 'lowest_user' doesn't exist either" do
    File.chown(CONFIG['nonexistant_uid'], nil, @environment_rb)
    spawn_stub_application(:lowest_user => CONFIG['nonexistant_user']) do |app|
      read_dumped_info[:username].should == my_username
    end
  end
  
  it "doesn't switch user if 'lower_privilege' is set to false" do
    File.chown(uid_for('normal_user_2'), nil, @environment_rb)
    spawn_stub_application(:lower_privilege => false) do |app|
      read_dumped_info[:username].should == my_username
    end
  end
  
  it "sets $HOME to the user's home directory, after privilege lowering" do
    spawn_stub_application(:lowest_user => CONFIG['normal_user_1']) do |app|
      read_dumped_info[:home].should == Etc.getpwnam(CONFIG['normal_user_1']).dir
    end
  end
  
  def read_dumped_info
    return YAML.load_file("#{@stub.app_root}/dump.yml")
  end
  
  def my_username
    return `whoami`.strip
  end
  
  def uid_for(name)
    return Etc.getpwnam(CONFIG[name]).uid
  end
end