Capistrano::Configuration.instance(:must_exist).load do
  namespace :ndr_dev_support do
    desc <<~DESC
      Ensure that the required ruby version is installed.

      This can be installed from /opt/rbenv.tar.gz (first installation only) or vendor/rbenv/

      To place an offline copy of rbenv in /opt/rbenv.tar.gz
      For ruby 3.1.6, run the following commands:
      $ mkdir clone_rbenv
      $ git clone https://github.com/rbenv/rbenv.git clone_rbenv/.rbenv
      $ git clone https://github.com/rbenv/ruby-build.git clone_rbenv/.rbenv/plugins/ruby-build
      $ mkdir clone_rbenv/.rbenv/cache
      $ (cd clone_rbenv/.rbenv/cache; curl -O https://cache.ruby-lang.org/pub/ruby/3.1/ruby-3.1.6.tar.gz)
      $ (cd clone_rbenv; rm -f ../rbenv.tar.gz; tar czf ../rbenv.tar.gz .rbenv)
      $ rm -rf clone_rbenv
      $ scp -p rbenv.tar.gz app-server:/opt/rbenv.tar.gz

      To add rbenv, ruby-build and additional ruby versions to the application vendor directory
      For ruby 3.2.6:
      $ mkdir clone_rbenv
      $ git clone https://github.com/rbenv/rbenv.git clone_rbenv/.rbenv
      $ mkdir -p vendor/rbenv; rm -f vendor/rbenv/rbenv.tar.gz
      $ tar czf vendor/rbenv/rbenv.tar.gz -C clone_rbenv .rbenv
      $ rm -rf clone_rbenv
      $ mkdir clone_ruby-build
      $ git clone https://github.com/rbenv/ruby-build.git clone_ruby-build/ruby-build
      $ mkdir -p vendor/rbenv/cache; rm -f vendor/rbenv/ruby-build.tar.gz
      $ tar czf vendor/rbenv/ruby-build.tar.gz -C clone_ruby-build ruby-build
      $ rm -rf clone_ruby-build
      $ (cd vendor/rbenv/cache; curl -O https://cache.ruby-lang.org/pub/ruby/3.2/ruby-3.2.6.tar.gz)
      $ git add vendor/rbenv/{rbenv,ruby-build}.tar.gz vendor/rbenv/cache/*
    DESC
    task :install_ruby do
      version = fetch(:ruby)
      # Note that ruby 3.1.x on CentOS 7 generally installs successfully but then reports an error:
      #   ERROR:  While executing gem ... (URI::InvalidURIError)
      #   bad URI(is not URI?): "bundler\r"
      # For this reason, we ignore the exit status, and run our own test.
      #
      # For some reason, SSH keepalive options have no effect with capistrano 2 and net-ssh 7.
      # So we run a poor-man's keepalive, because this installation can take over 10 minutes
      # and some of our SSH servers disconnect inactive sessions after 5 minutes.
      # We have a keepalive time limit of 40 minutes in case the installation fails unexpectedly.
      #
      # We remove ~/.rbenv paths from capistrano-defined PATH when running `rbenv init`
      # so that it knows the path is needed in ~/.bash_profile
      #
      # We use latest_release: this is broadly well-defined, and will point to the in-progress
      # release if we're part way through a deployment, or the most recent release if run
      # after a deployment has happened, or be blank if attempted after cap deploy:setup
      run <<~SHELL
        set -e;
        if ! rbenv versions --bare 2> /dev/null | grep -q ^#{Regexp.escape(version)}$; then
          echo Installing ruby #{version};
          { sleep 10; for i in `seq 1 80`; do echo -n '.'; sleep 30; done & } 2> /dev/null;
          sudo -i -n -u #{fetch(:application_user)} sh -c "
            if [ ! -e .rbenv ] && [ -e /opt/rbenv.tar.gz ]; then
              tar xf /opt/rbenv.tar.gz .rbenv;
              PATH=\\`echo \\"\\$PATH\\"|sed -e \\"s_[^:=]*/[.]rbenv[^:]*:__g\\"\\` .rbenv/bin/rbenv init bash;
            fi;
            if [ ! -e .rbenv ] && [ -f #{latest_release}/vendor/rbenv/rbenv.tar.gz ]; then
              tar xf #{latest_release}/vendor/rbenv/rbenv.tar.gz .rbenv;
              PATH=\\`echo \\"\\$PATH\\"|sed -e \\"s_[^:=]*/[.]rbenv[^:]*:__g\\"\\` .rbenv/bin/rbenv init bash;
            fi;
            if [ ! -e .rbenv ]; then
              echo rbenv not installed: aborting;
            else
              if [ -d #{latest_release}/vendor/rbenv/cache ] && [ -n \\"\\`ls #{latest_release}/vendor/rbenv/cache\\`\\" ]; then
                mkdir -p .rbenv/cache/;
                cp -nvp #{latest_release}/vendor/rbenv/cache/* .rbenv/cache/;
              fi;
              if [ -f #{latest_release}/vendor/rbenv/ruby-build.tar.gz ]; then
                mkdir -p .rbenv/plugins/;
                tar xf #{latest_release}/vendor/rbenv/ruby-build.tar.gz -C .rbenv/plugins/ ruby-build;
              fi;
              eval \\"\\$(.rbenv/bin/rbenv init - --no-rehash bash)\\";
              export TMPDIR=\\`mktemp -d \\"\\$HOME\\"/rbenv_tmp_XXXX\\`;
              if rbenv install #{version} --skip-existing 2>&1; then
                RBENV_VERSION=#{version} ruby --version;
                rm -rf \\"\\`printenv TMPDIR\\`\\";
                rbenv global #{version};
              fi;
            fi;
          ";
          { kill % && wait; } 2> /dev/null;
          set -e;
          if [ "`RBENV_VERSION=#{version} gem list --exact --installed bundler`" == "true" ]; then
            echo 'Please ignore the following error above:';
            echo '> ERROR:  While executing gem ... (URI::InvalidURIError)';
            echo '> bad URI(is not URI?): "bundler\\r"';
            echo Successfully installed ruby #{version};
          else
            echo ERROR: Failure installing ruby #{version}: aborting;
            exit 1;
          fi;
        fi
      SHELL
    end
  end

  before 'bundle:install', 'ndr_dev_support:install_ruby'
end