require 'pathname'
require 'tempfile'

module Geordi
  module FirefoxForSelenium
    include Geordi::Interaction

    FIREFOX_FOR_SELENIUM_BASE_PATH = Pathname.new('~/bin/firefoxes').expand_path
    FIREFOX_FOR_SELENIUM_PROFILE_NAME = 'firefox-for-selenium'
    DEFAULT_FIREFOX_VERSION = "5.0.1"
    VERSION_SPECIFICATION_FILE = Pathname.new(".firefox-version")

    def self.install(version)
      Installer.new(version).run
    end

    def self.path_from_config
      PathFromConfig.new.run
    end

    def self.path(version)
      FIREFOX_FOR_SELENIUM_BASE_PATH.join(version)
    end

    def self.binary(version, name = "firefox")
      path(version).join(name)
    end

    def self.setup_firefox
      path = path_from_config
      if path
        ENV['PATH'] = "#{path}:#{ENV['PATH']}"
      end
    end


    class PathFromConfig
      include Geordi::Interaction

      def run
        unless system_firefox
          get_version
          validate_install
          path
        end
      end

      private

      def path
        FirefoxForSelenium.path(@version)
      end

      def system_firefox
        version_from_cuc_file == "system"
      end

      def get_version
        @version = version_from_cuc_file || default_version
      end

      def default_version
        warn "No firefox version given, defaulting to #{DEFAULT_FIREFOX_VERSION}."
        note "Specify a version by putting it in a file named \"#{VERSION_SPECIFICATION_FILE}\"."
        puts
        DEFAULT_FIREFOX_VERSION
      end

      def validate_install
        unless FirefoxForSelenium.binary(@version).exist?
          note "Firefox #{@version} not found."

          puts strip_heredoc(<<-INSTRUCTIONS)
          Install it with
            geordi setup_firefox_for_selenium #{@version}

          If you want to use your system firefox and not see this message, add
          a .firefox-version file with the content "system".

          INSTRUCTIONS

          prompt "Press ENTER to continue or press CTRL+C to abort."
        end
      end

      def version_from_cuc_file
        File.read(VERSION_SPECIFICATION_FILE).strip if VERSION_SPECIFICATION_FILE.exist?
      end

    end


    class Installer
      include Geordi::Interaction

      def initialize(version)
        @version = version
      end

      def run
        say_hello
        check_if_run_before
        download_firefox
        create_separate_profile # do this before the patching because the patched binary calls firefox with a profile that does not yet exist
        patch_old_firefox
        configure_old_firefox
        kkthxbb
      end


      private

      def execute_command(cmd)
        system(cmd) or raise "Error while executing command: #{cmd}"
      end

      def run_firefox_for_selenium(args = '')
        execute_command("PATH=#{path}:$PATH firefox #{args}")
      end

      def path
        FirefoxForSelenium.path(@version)
      end

      def download_url
        "ftp://ftp.mozilla.org/pub/firefox/releases/#{@version}/"
      end

      def binary
        FirefoxForSelenium.binary(@version)
      end

      def original_binary
        FirefoxForSelenium.binary(@version, "firefox-original")
      end

      def say_hello
        execute_command('clear')

        puts strip_heredoc(<<-HELLO)
        Whenever Firefox updates, Selenium breaks. This is annoying. This
        script will help you create an unchanging version of Firefox for your
        Selenium tests.

        In particular, this new copy of Firefox will have the following
        properties:

        - It won't update itself with a newer version
        - It can co-exist with your regular Firefox installation (which you can
          update at will)
        - It will use a profile separate from the one you use for regular
          Firefox browsing
        - It will not try to re-use existing Firefox windows
        - It will automatically be used for your Selenium scenarios if you run
          your Cucumber using the cuc binary from the geordi gem.
        - It will live in #{path}
        HELLO

        prompt "Press ENTER when you're ready to begin."
      end

      def check_if_run_before
        if original_binary.exist?
          note 'This version seems to be already installed.'
          prompt 'Press ENTER to continue anyway or press CTRL+C to abort.'
        end
      end

      def download_firefox
        path.mkpath

        puts strip_heredoc(<<-INSTRUCTION)
        Please download an old version of Firefox from: #{download_url}
        Unpack it with: tar xvjf firefox-#{@version}.tar.bz2 -C #{path} --strip-components=1
        Now #{path.join('firefox')} should be the firefox binary, not a directory.
        INSTRUCTION
        prompt "Press ENTER when you're done."

        File.file?(binary) or raise "Could not find #{binary}"
      end

      def create_separate_profile
        note "Creating a separate profile named '#{FIREFOX_FOR_SELENIUM_PROFILE_NAME}' so your own profile will be safe..."
        # don't use the patched firefox binary for this, we don't want to give
        # a -p option here
        execute_command("PATH=#{path}:$PATH firefox -no-remote -CreateProfile #{FIREFOX_FOR_SELENIUM_PROFILE_NAME}")
        puts
      end

      def patch_old_firefox
        note "Patching #{binary} so it uses the new profile and never re-uses windows from other Firefoxes..."
        execute_command("mv #{binary} #{original_binary}")
        execute_command("mv #{binary}-bin #{original_binary}-bin")
        patched_binary = Tempfile.new('firefox')
        patched_binary.write strip_heredoc(<<-PATCH)
          #!/usr/bin/env ruby
          exec('#{original_binary}', '-no-remote', '-P', '#{FIREFOX_FOR_SELENIUM_PROFILE_NAME}', *ARGV)
          PATCH
        patched_binary.close
        execute_command("mv #{patched_binary.path} #{binary}")
        execute_command("chmod +x #{binary}")
        puts
      end

      def configure_old_firefox
        puts strip_heredoc(<<-INSTRUCTION)
        You will now have to do some manual configuration.

        This script will open the patched copy of Firefox when you press ENTER.
        Please perform the following steps manually:

        - Disable the default browser check when Firefox launches
        - Check that the version number is correct (#{@version})
        - You should not see your bookmarks, add-ons, plugins from your regular
          Firefox profile
        - Disable all automatic updates under Edit / Preferences / Advanced /
          Update (do this quickly or Firefox will already have updated)
        INSTRUCTION

        prompt 'Open the patched copy of Firefox with ENTER.'
        run_firefox_for_selenium
      end

      def kkthxbb
        success "Congratulations, you're done!"

        puts
        puts strip_heredoc(<<-INSTRUCTION)
        Your patched copy of Firefox will be used when you run Cucumber using
        the cucumber script that comes with the geordi gem. If you prefer to run
        Cucumber on your own, you must call it like this:

          PATH=#{path}:$PATH cucumber

        Enjoy!
        INSTRUCTION
      end

    end
  end
end