module Merb
  module Virtuozzo
    class << self
      ##
      # Returns the expected location of a deployment configuration file.
      def config_file() Merb.root / "config" / "virtuozzo.yml" end
        
      ##
      # Returnes the expected location of a sample configuration file.
      def sample_dest() Merb.root / "config" / "virtuozzo.yml.sample" end
        
      ##
      # Returnes the location of the template for a sample configuration file.
      def sample_source() File.dirname(__FILE__) / "virtuozzo.yml.sample" end

      ##
      # Copies the template for the sample configuration file into the
      # application's config folder.
      def copy_sample_config
        FileUtils.cp sample_source, sample_dest unless File.exists?(sample_dest)
      end

      ##
      # Parses the configuration file converting keys to symbols and stores
      # values to Merb::Plugins.config[:virtuozzo].
      def config
        @config ||= begin
          # Convert string keys to symbols
          full_config = Erubis.load_yaml_file(config_file)
          config = (Merb::Plugins.config[:virtuozzo] = {})
          (full_config[Merb.environment.to_sym] || full_config[Merb.environment] || full_config[:development]).each do |key, value|
            config[key.to_sym] = value
          end
          config
        end
      end
      
      ##
      # Extract and merge default values from configuration options.
      def config_options(config = {})
        options = {}

        options[:host] = (config[:host] || "https://localhost:4646")
        options[:username] = (config[:username] || config[:user] || "")
        options[:password] = config[:password] || ""

        options
      end

      ##
      # Singleton method for accessing an established connection session.
      def connection
        @connection ||= connect
      end

      ##
      # Establishes connection or logs errors returning the connection on
      # success.
      def connect
        if File.exists?(config_file)
          Merb.logger.info!("Connecting to the Virtuozzo Agent at '#{config[:host]}' ...")
          
          o = config_options(config)
          
          connection_options = [
              o[:host],
              o[:username],
              o[:password],
              o.except(:host, :username, :password)
            ]
          
          @connection = ::Virtuozzo::SOAP::Connection.new(*connection_options)
          Merb.logger.error!("Connection Error: #{e}") unless @connection
          connection
        else
          copy_sample_config
          Merb.logger.set_log(STDERR)
          Merb.logger.error! "No virtuozzo.yml file found in #{Merb.root}/config."
          Merb.logger.error! "A sample file was created called config/virtuozzo.yml.sample for you to copy and edit."
          exit(1)
        end
      end
    end
  end
end