# Copyright (C) 2011-2012 RightScale, Inc, All Rights Reserved Worldwide.
#
# THIS PROGRAM IS CONFIDENTIAL AND PROPRIETARY TO RIGHTSCALE
# AND CONSTITUTES A VALUABLE TRADE SECRET. Any unauthorized use,
# reproduction, modification, or disclosure of this program is
# strictly prohibited. Any use of this program by an authorized
# licensee is strictly subject to the terms and conditions,
# including confidentiality obligations, set forth in the applicable
# License Agreement between RightScale.com, Inc. and
# the licensee

module RightConf

  # Specify rbenv and ruby-build git revision for installation
  RBENV_GIT_REPO = 'git://github.com/sstephenson/rbenv.git'
  RBENV_GIT_REVISION = "9375e99f921f428849f19efe2a2e500b3295d1a7"

  RUBYBUILD_GIT_REPO = 'git://github.com/sstephenson/ruby-build.git'
  RUBY_BUILD_GIT_REVISION = "28b9bcb6df1bc18fb2b06e25ee65f397ac3d4632"

  # Local installation target folders
  RBENV_INSTALL_TARGET = "#{ENV['HOME']}/.rbenv"
  RUBYBUILD_TARGET = "#{RBENV_INSTALL_TARGET}/plugins/ruby-build"


  class RubyConfigurator

    include Configurator

    register :ruby

    description "Installs ruby interpreter and rubygems.\n" +
                'Installs and uses rbenv on supported (i.e. non-Windows) platforms'

    setting 'version',  'Ruby version using rbenv notation (see "rbenv versions")', :required => true

    updater lambda { update_rbenv_installation }


    # Message to display to the user when rbenv isn't in the path.
    PATH_ADVICE  = "You should add rbenv to your path and 'eval \"$(rbenv init -)\"' to your .bash_profile / .bashrc etc. " +
        "so rbenv is properly initialized in new shells.\n\n" +
        "If you are a bash user (e.g. Mac OS X), you can add the following to ~/.bash_profile:\n\n" +
        "  echo 'export PATH=\"$HOME/.rbenv/bin:$PATH\"' >> ~/.bash_profile\n" +
        "  echo 'eval \"$(rbenv init -)\"' >> ~/.bash_profile\n\n"

    # Let configurator run, it is idempotent
    #
    # === Return
    # false:: Always return false
    def check_linux
      false
    end
    alias :check_darwin :check_linux
    alias :check_windows :check_linux

    # Switch to ruby version defined in settings
    # Use rbenv and install it if needed
    #
    # === Return
    # true:: Always return true
    def run_linux
      if Command.execute('rvm').success?
        report_fatal "rconf detected an installation of RVM, rconf now uses rbenv to configure ruby versions.\n" +
          "Unfortunately rbenv and RVM cannot be installed together on the same machine (see https://github.com/sstephenson/rbenv/).\n" +
          "Please uninstall RVM and try again ('rvm implode' will delete RVM and all installed rubies and gems).\n" +
          "Once RVM is uninstalled please start a new shell (you may also need to remove references to RVM from your ~/.bash_profile)"
        return true
      end
      check_rbenv
      return true if aborting
      check_ruby
      Command.set_ruby(ruby_version)
     true
    end
    alias :run_darwin :run_linux

    # Switch to ruby version defined in settings
    # TBD
    #
    # === Return
    # true:: Always return true
    def run_windows
    end

    protected

    # Make our version specifier compatible with RVM-style specifiers (override base class accessor)
    def ruby_version
      @ruby_version ||= version.start_with?('ruby-') ? version[5..-1] : version
    end

    # Check whether rbenv and ruby-build are installed and installs it/them if not
    #
    # === Return
    # true:: Always return true
    def check_rbenv
      rbenv_present = File.exist?(File.join(ENV['HOME'], '.rbenv', 'bin', 'rbenv'))

      res = Command.execute('rbenv')
      rbenv_in_path = res.success?

      if rbenv_present && !rbenv_in_path
        # Bail if rbenv isn't correctly initialized (we can't use it in this state)
        post_note "rconf detected rbenv is installed in #{rbenv_path} but it is not in the PATH.\n" + PATH_ADVICE
        aborting(true)
      elsif rbenv_in_path
        # rbenv is installed and initialized; make sure we have a suitable version
        res.output =~ /^rbenv ([0-9]+)\.([0-9]+)\.([0-9]+)$/
        maj, min, build = [$1.to_i, $2.to_i, $3.to_i]
        if maj == 0 && min < 4
          report_fatal("rconf requires rbenv version 0.4.0 or greater, you have #{maj}.#{min}.#{build} installed, "+
                       "please upgrade (e.g. via 'brew upgrade rbenv') and try again")
        end
      else
        # No sign of rbenv; try to install it
        install_rbenv_from_git
      end

      true
    end


    # Overwrite ruby-build definition file to use our own, patched version of REE and to set certain compile options
    # so that it REE works with newer versions of GCC as well.
    #
    # === Return
    # true:: Always return true
    def self.add_custom_ree_definition
      curr_dir=File.dirname(__FILE__)
      patched_ree = "#{curr_dir}/../../patches/ree-1.8.7-2012.02-rs-custom"
      FileUtils.cp patched_ree, "#{RUBYBUILD_TARGET}/share/ruby-build/ree-1.8.7-2012.02"

      true
    end


    # Update rbenv and ruby-build to the version specified through the git commit version constant
    #
    # === Return
    # true:: Always return true
    def self.update_rbenv_installation
      puts "Updating rbenv ..."
      if File.directory?("#{RBENV_INSTALL_TARGET}/.git")
        # Perform the pull only if rbenv has been installed by using a git pull (and not through a package manager)
        system("cd #{RBENV_INSTALL_TARGET}; git fetch -q; git checkout -q #{RBENV_GIT_REVISION}")
      end

      puts "Updating ruby-build ..."
      if File.directory?("#{RUBYBUILD_TARGET}/.git")
        # Perform the pull only if ruby-build has been installed by using a git pull (and not through a package manager)
        # Before checking out the new branch, reset the repository to avoid conflicts
        system("cd #{RUBYBUILD_TARGET}; git reset -q --hard; git fetch -q; git checkout -q #{RUBY_BUILD_GIT_REVISION}")

        # Add our ree definition again because the repository has been reset
        RubyConfigurator.add_custom_ree_definition
      end

      true
    end


    # Install rbenv
    # 1. Fetch rbenv from repository and install it
    # 2. Fetch ruby-build from repository and install it
    # 3. Install custom ree installation definition into ruby-build so that our patched REE gets installed
    #
    # === Return
    # true:: Always return true
    def install_rbenv_from_git

      # Require: git
      res = Command.execute('git', '--version').success?
      if !res
        # Install git
        opts = { :report => true, :post_install => update_msg }.merge(abort_option('Failed to install git, required for rbenv'))
        PackageInstaller.install('git', opts)
      end


      # Fetch and install rbenv
      # ***********************

      # Fetch rbenv from git repo
      Command.execute('git', 'clone', RBENV_GIT_REPO, RBENV_INSTALL_TARGET, {:abort_on_failure => 'Git clone of rbnev failed - server down?'})
      Kernel.system("cd #{RBENV_INSTALL_TARGET}; git checkout #{RBENV_GIT_REVISION}")

      # Fetch, install and patch ruby-build
      # ***********************************

      # Create plugins directory (target for ruby-build)
      ret = FileUtils.mkdir_p(RUBYBUILD_TARGET)
      if !ret
        report_fatal("Could not create directory: #{RUBYBUILD_TARGET}");
      end

      Command.execute('git', 'clone', RUBYBUILD_GIT_REPO, RUBYBUILD_TARGET, {:abort_on_failure => 'Git clone of ruby-build failed - server down?'})
      Kernel.system("cd #{RUBYBUILD_TARGET}; git checkout #{RUBY_BUILD_GIT_REVISION}")

      RubyConfigurator.add_custom_ree_definition
    end

    # Check .ruby-version and its content
    #
    # === Return
    # true:: Always return true
    def check_ruby
      unless Command.execute('rbenv', 'local', ruby_version).success?
        report_check("Installing ruby #{ruby_version} (this will take a while, please be patient)")
        Platform.dispatch(ruby_version) { :install_ruby }
      end

      which = Command.execute('which', 'ruby').output.strip
      if (which =~ %r(^(/usr)?/bin.*ruby$))
        post_note "Your PATH is not setup correctly for rbenv; ('which ruby' => #{which}).\n" + PATH_ADVICE
        aborting(true)
      end

      true
    end

    # Install given ruby version using rbenv
    # Install any prerequesites first
    #
    # === Parameters
    # ruby(String):: Ruby version compatible with rbenv
    #
    # === Return
    # true:: Always return true
    def install_ruby(ruby)
      Platform.dispatch(ruby) { :install_ruby_prerequisites }
      # Can't abort on failure rbenv install seems to exist with a non zero error code even when successful :(
      Command.execute('rbenv', 'install', ruby)
      report_success
      post_note "rconf installed ruby #{ruby} and needs to be restarted so the right ruby tools get activated\nPlease run 'rconf' again."
      aborting(true)
      true
    end

    # Install given ruby version using rbenv
    # On Lion, need to setup CC env var before running rbenv install
    #
    # === Parameters
    # ruby(String):: Ruby version compatible with rbenv
    #
    # === Return
    # true:: Always return true
    def install_ruby_darwin(ruby)
      Platform.dispatch(ruby) { :install_ruby_prerequisites }
      c_version = `system_profiler SPDeveloperToolsDataType -xml | xpath "//*[text()='_items']/following-sibling::array/dict/child::key[text()='spdevtools_version']/following-sibling::string/text()" 2> /dev/null`
      env = {}

      # Ensure we're using a sane GCC 4.2, not Apple's LLVM-based lookalike.
      gcc42 = ['/usr/local/bin/gcc-4.2', '/usr/bin/gcc-4.2'].detect { |p| File.executable?(p) }
      if c_version =~ /^4\.2\.[0-9]+/
        if gcc42.nil?
          report_fatal("The C compiler included with Xcode #{c_version} produces buggy ruby interpreters, please install the C compilers from https://github.com/downloads/kennethreitz/osx-gcc-installer/GCC-10.7-v2.pkg or update your version of Xcode and re-run rconf")
        else
          env['CC'] = gcc42
        end
      end

      # Ruby 1.8 force-installs the Tk stdlib extension, no way to opt out.
      # Ensure XQuartz is installed and its headers are on the path.
      if ruby =~ /1\.8/
        if File.directory?('/opt/X11/include')
          env['CC'] = gcc42
          env['CPPFLAGS'] = '-I/opt/X11/include'
        else
          report_fatal("Installing ruby 1.8 (or ree 1.8) on Mac OS X requires that XQuartz be installed on the machine first, please go to http://xquartz.macosforge.org/landing/, install XQuartz and try again")
        end
      end

      Command.execute('rbenv', 'install', ruby, :abort_on_failure => 'Failed to install ruby', :env => env)
      report_success
    end

    # Make sure to install all required linux packages first
    #
    # === Return
    # true:: Always return true
    def install_ruby_prerequisites_linux_ubuntu(ruby)
      report_check("Installing required packages, this could take a while")
      packages = []
      packages = %w(build-essential bison openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev)
      Command.sudo('apt-get', 'install', '-y', *packages)
      report_success
    end

    alias install_ruby_prerequisites_linux_debian install_ruby_prerequisites_linux_ubuntu

    # Make sure to install all required CentOS / RedHhat packages first
    # NOTE: For centos 5.4 final iconv-devel might not be available :(
    #
    # === Return
    # true:: Always return true
    def install_ruby_prerequisites_linux_centos(ruby)
      report_check("Installing required packages, this could take a while")
      packages = []
      if ruby =~ /^ree-|^ruby-/
        packages = %w(gcc-c++ patch readline readline-devel zlib zlib-devel libyaml-devel libffi-devel openssl-devel iconv-devel)
      end # TBD Define packages needed for other rubies
      Command.sudo('yum', 'install', '-y', *packages)
      report_success
    end
    alias :install_ruby_prerequisites_linux_redhat :install_ruby_prerequisites_linux_centos

    # No pre-requesites to install ree or Matz ruby on Mac (TBD others)
    #
    # === Return
    # true:: Always return true
    def install_ruby_prerequisites_darwin(ruby)
      version_output = `sw_vers`
      if m = /ProductVersion:\s*([0-9.]+)/m.match(version_output)
        osx_version = m[1].split(".").map { |c| c.to_i }
      else
        raise RuntimeError, "Can't determine OS X version from sw_vers output (#{version_output})"
      end

      if (osx_version[0] > 10 || osx_version[1] > 6)
        report_check("installing non-LLVM GCC 4.2")
        PackageInstaller.install('https://raw.github.com/Homebrew/homebrew-dupes/master/apple-gcc42.rb', :abort_on_failure => "Could not install gcc 4.2")
        report_success
      end

      true
    end


    # Produce abort on failure option
    #
    # === Parameters
    # message(String):: Abort message to be used in case abort option should be set
    #
    # === Return
    # {}:: Empty hash if 'abort_on_failure' is notset
    # opts(Hash):: Abort option with give message otherwise
    def abort_option(message)
      opts = abort_on_failure && { :abort_on_failure => message } || {}
    end

  end
end