# 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

  class CassandraConfigurator

    SOURCE_BASE_URL  = 'http://archive.apache.org/dist/cassandra/VERSION/apache-cassandra-VERSION-bin.tar.gz'
    DEFAULT_CASSANDRA_INSTALL = ['/opt/cassandra', File.join(ENV['HOME'], 'cassandra')]

    include Configurator

    register :cassandra

    description 'Installs Cassandra'

    setting  'version',         'Cassandra version to install', :required => true
    setting  'install_path',    'Path to Cassandra installation directory, uses /opt/cassandra if it ' +
                                  'is writable by the current user or ~/cassandra otherwise by default'
    setting  'abort_on_failure','Whether to abort if Cassandra failed to install (false by default)'
    setting  'endpoint_snitch', 'Set custom endpoint snitch for installed cassandra'

    # Check whether Cassandra is installed
    #
    # === Return
    # true:: If Cassandra is installed
    # false:: Otherwise
    def check_linux
      report_check('Checking for Cassandra')
      installed = Command.execute('cassandra', '-h').success?
      report_result(installed)
      installed
    end
    alias :check_darwin :check_linux

    # Check on windows
    #
    # === Return
    # true:: Always return true
    def check_windows
      true
    end

    # Install Linux Mercurial package
    #
    # === Return
    # true:: Always return true
    def run_linux
      install_path(default_install_path) if install_path.nil?
      abort_on_failure(true) if abort_on_failure.nil?
      report_check('Installing Cassandra')
      url = SOURCE_BASE_URL.gsub('VERSION', version)
      if File.exist?(install_path)
        FileUtils.rm_rf("#{install_path}_old")
        FileUtils.mv(install_path, "#{install_path}_old")
        post_note "Had to move #{install_path} to #{install_path}_old"
      end
      FileUtils.mkdir_p(install_path)
      Dir.chdir(install_path) do
        Command.execute('curl', '-O', '-f', url, abort_option('Failed to download Cassandra')) unless File.exist?(File.join(install_path, File.basename(url)))
        Command.execute('tar', 'xvzf', File.basename(url), abort_option('Failed to untar Cassandra'))
      end
      bin_path = File.join(install_path, "apache-cassandra-#{version}", 'bin')
      if EnvironmentUpdater.update("PATH=$PATH:#{bin_path}", ['PATH'])
        post_note 'Cassandra was installed, please reload your shell to activate it and re-run rconf'
        aborting(true)
      end
      report_success
      if (endpoint_snitch)
        report_check 'Change cassandra configuration.'
        config_path = File.join(install_path, "apache-cassandra-#{version}", 'conf', 'cassandra.yaml')
        backup_ext = '.orig'
        Command.execute('sed', '-i', backup_ext, '-e', "s%^endpoint_snitch: .*$%endpoint_snitch: #{endpoint_snitch}%", config_path)
        report_success
        post_note "Origin config file in #{config_path}#{backup_ext}"
      end
    end
    alias :run_darwin :run_linux

    # Install Windows software
    #
    # === Return
    # true:: Always return true
    def run_windows
      # TBD
    end

    protected

    # Retrieve default install path
    # Try /opt/cassandra and revert to ~/cassandra if not writable
    #
    # === Return
    # path:: Default cassandra install path
    def default_install_path
      path = if File.exist?('/opt')
        if File.exist?('/opt/cassandra')
          pick_default_path(File.writable?('/opt/cassandra'))
        else
          res = Command.execute('mkdir', '/opt/cassandra')
          pick_default_path(res.success?)
        end
      else
        res = Command.execute('mkdir', '-p', '/opt/cassandra')
        pick_default_path(res.success?)
      end
    end

    # First or second choice nginx install path
    #
    # === Parameter
    # first_choice(TrueClass|FalseClass):: Whether to use first or second choice path
    #
    # === Return
    # path(String):: Path
    def pick_default_path(first_choice)
      path = DEFAULT_CASSANDRA_INSTALL[first_choice && 0 || 1]
    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