class Card
  require 'card/location'

  # Card::Env can differ for each request; Card.config should not
  module Env
    class << self
      def reset args={}
        @@env = { main_name: nil }

        if c = args[:controller]
          self[:controller] = c
          self[:session]    = c.request.session
          self[:params]     = c.params
          self[:ip]         = c.request.remote_ip
          self[:ajax]       = c.request.xhr? || c.request.params[:simulate_xhr]
          self[:html]       = [nil, 'html'].member?(c.params[:format])
          self[:host]       = Card.config.override_host     || c.request.env['HTTP_HOST']
          self[:protocol]   = Card.config.override_protocol || c.request.protocol
        end
      end

      def [] key
        @@env[key.to_sym]
      end

      def []= key, value
        @@env[key.to_sym] = value
      end


      def params
        self[:params] ||= {}
      end

      def session
        self[:session] ||= {}
      end

      def success cardname=nil
        self[:success] ||= Card::Success.new(cardname, params[:success])
      end


      def ajax?
        self[:ajax]
      end

      def html?
        !self[:controller] || self[:html]
      end

      def method_missing method_id, *args
        case args.length
        when 0 ; self[ method_id ]
        when 1 ; self[ method_id ] = args[0]
        else   ; super
        end
      end
    end

    # session history helpers: we keep a history stack so that in the case of
    # card removal we can crawl back up to the last un-removed location
    module LocationHistory
      #include Card::Location

      def location_history
        session[:history] ||= [Card::Location.card_path('')]
        session[:history].shift if session[:history].size > 5
        session[:history]
      end

      def save_location card
        return if Env.ajax? || !Env.html? || !card.known? ||
                  (card.codename == 'signin')
        discard_locations_for card
        session[:previous_location] =
          Card::Location.card_path card.cardname.url_key
        location_history.push previous_location
      end

      def previous_location
        return unless location_history
        session[:previous_location] ||= location_history.last
      end

      def discard_locations_for card
        # quoting necessary because cards have things like "+*" in the names..
        session[:history] = location_history.reject do |loc|
          if (url_key = url_key_for_location(loc))
            url_key.to_name.key == card.key
          end
        end.compact
        session[:previous_location] = nil
      end

      def save_interrupted_action uri
        session[:interrupted_action] = uri
      end

      def interrupted_action
        session.delete :interrupted_action
      end

      def url_key_for_location(location)
        location.match( /\/([^\/]*$)/ ) ? $1 : nil
      end
    end

    extend LocationHistory

  end



  Env.reset
end