require 'spec_helper'

describe 'VagrantPlugins::GuestAlpine::Cap::ChangeHostname' do
  let(:described_class) do
    VagrantPlugins::GuestAlpine::Plugin.components.guest_capabilities[:alpine].get(:change_host_name)
  end
  let(:machine) { double('machine') }
  let(:communicator) { VagrantTests::DummyCommunicator::Communicator.new(machine) }
  let(:old_hostname) { 'oldhostname.olddomain.tld' }

  before do
    allow(machine).to receive(:communicate).and_return(communicator)
    communicator.stub_command('hostname -f', stdout: old_hostname)
  end

  after do
    communicator.verify_expectations!
  end

  describe '.change_host_name' do
    it 'updates /etc/hostname on the machine' do
      communicator.expect_command("echo 'newhostname' > /etc/hostname")
      described_class.change_host_name(machine, 'newhostname.newdomain.tld')
    end

    it 'does nothing when the provided hostname is not different' do
      described_class.change_host_name(machine, 'oldhostname.olddomain.tld')
      expect(communicator.received_commands).to eq(['hostname -f'])
    end

    it 'refreshes the hostname service with the hostname command' do
      communicator.expect_command('hostname -F /etc/hostname')
      described_class.change_host_name(machine, 'newhostname.newdomain.tld')
    end

    it 'renews dhcp on the system with the new hostname' do
      communicator.expect_command('ifdown -a; ifup -a; ifup eth0')
      described_class.change_host_name(machine, 'newhostname.newdomain.tld')
    end

    describe 'flipping out the old hostname in /etc/hosts' do
      let(:sed_command) do
        # Here we run the change_host_name through and extract the recorded sed
        # command from the dummy communicator
        described_class.change_host_name(machine, 'newhostname.newdomain.tld')
        communicator.received_commands.find { |cmd| cmd =~ /^sed/ }
      end

      # Now we extract the regexp from that sed command so we can do some
      # verification on it
      let(:expression) { sed_command.sub(%r{^sed -ri '\(.*\)' /etc/hosts$}, "\1") }
      let(:search)     { Regexp.new(expression.split('@')[1], Regexp::EXTENDED) }
      let(:replace)    { expression.split('@')[2] }

      let(:grep_command) { "grep '#{old_hostname}' /etc/hosts" }

      before do
        communicator.stub_command(grep_command, exit_code: 0)
      end

      it 'works on an simple /etc/hosts file' do
        original_etc_hosts = <<-ETC_HOSTS.gsub(/^ */, '')
          127.0.0.1 localhost
          127.0.1.1 oldhostname.olddomain.tld oldhostname
        ETC_HOSTS

        modified_etc_hosts = original_etc_hosts.gsub(search, replace)

        expect(modified_etc_hosts).to eq <<-RESULT.gsub(/^ */, '')
          127.0.0.1 localhost
          127.0.1.1 newhostname.newdomain.tld newhostname
        RESULT
      end

      it 'does not modify lines which contain similar hostnames' do
        original_etc_hosts = <<-ETC_HOSTS.gsub(/^ */, '')
          127.0.0.1 localhost
          127.0.1.1 oldhostname.olddomain.tld oldhostname
          # common prefix, but different fqdn
          192.168.12.34 oldhostname.olddomain.tld.different
          # different characters at the dot
          192.168.34.56 oldhostname-olddomain.tld
        ETC_HOSTS

        modified_etc_hosts = original_etc_hosts.gsub(search, replace)

        expect(modified_etc_hosts).to eq <<-RESULT.gsub(/^ */, '')
          127.0.0.1 localhost
          127.0.1.1 newhostname.newdomain.tld newhostname
          # common prefix, but different fqdn
          192.168.12.34 oldhostname.olddomain.tld.different
          # different characters at the dot
          192.168.34.56 oldhostname-olddomain.tld
        RESULT
      end

      it "appends 127.0.1.1 if it isn't there" do
        communicator.stub_command(grep_command, exit_code: 1)
        described_class.change_host_name(machine, 'newhostname.newdomain.tld')

        sed = communicator.received_commands.find { |cmd| cmd =~ /^sed/ }
        expect(sed).to be_nil

        echo = communicator.received_commands.find { |cmd| cmd =~ /^echo/ }
        expect(echo).to_not be_nil
      end

      context 'when the old fqdn has a trailing dot' do
        let(:old_hostname) { 'oldhostname.withtrailing.dot.' }

        it 'modifies /etc/hosts properly' do
          original_etc_hosts = <<-ETC_HOSTS.gsub(/^ */, '')
            127.0.0.1 localhost
            127.0.1.1 oldhostname.withtrailing.dot. oldhostname
          ETC_HOSTS

          modified_etc_hosts = original_etc_hosts.gsub(search, replace)

          expect(modified_etc_hosts).to eq <<-RESULT.gsub(/^ */, '')
            127.0.0.1 localhost
            127.0.1.1 newhostname.newdomain.tld newhostname
          RESULT
        end
      end
    end
  end
end