module SimpleNavigation

  # View helpers to render the navigation.
  #
  # Use render_navigation as following to render your navigation:
  # * call <tt>render_navigation</tt> without :level option to render your navigation as nested tree.
  # * call <tt>render_navigation(:level => x)</tt> to render a specific navigation level (e.g. :level => 1 to render your primary navigation, :level => 2 to render the sub navigation and so forth)
  #
  # ==== Examples (using Haml)
  #   #primary_navigation= render_navigation(:level => 1)
  #
  #   #sub_navigation= render_navigation(:level => 2)
  #
  #   #nested_navigation= render_navigation
  #
  # Please note that <tt>render_primary_navigation</tt> and <tt>render_sub_navigation</tt> still work, but have been deprecated and may be removed in a future release.
  module Helpers

    # Renders the navigation according to the specified options-hash.
    #
    # The following options are supported:
    # * <tt>:level</tt> - defaults to :nested which renders the the sub_navigation for an active primary_navigation inside that active primary_navigation item.
    #   Specify a specific level to only render that level of navigation (e.g. :level => 1 for primary_navigation etc...).
    # * <tt>:context</tt> - specifies the context for which you would render the navigation. Defaults to :default which loads the default navigation.rb (i.e. config/navigation.rb).
    #   If you specify a context then the plugin tries to load the configuration file for that context, e.g. if you call <tt>render_navigation(:context => :admin)</tt> the file config/admin_navigation.rb
    #   will be loaded and used for rendering the navigation.
    #
    def render_navigation(*args)
      args = [Hash.new] if args.empty?
      options = extract_backwards_compatible_options(*args)
      options = {:context => :default, :level => :nested}.merge(options)
      SimpleNavigation.load_config(options[:context])
      SimpleNavigation::Configuration.eval_config(self, options[:context])
      SimpleNavigation.handle_explicit_navigation
      case options[:level]
        when Integer
          active_item_container = SimpleNavigation.active_item_container_for(options[:level])
          active_item_container.render if active_item_container
        when :nested
          SimpleNavigation.primary_navigation.render(true)
        when :all
          SimpleNavigation.primary_navigation.render(true,:all=>true)
        else
          raise ArgumentError, "Invalid navigation level: #{options[:level]}"
      end
    end

    # Deprecated. Renders the primary_navigation with the configured renderer. Calling render_navigation(:level => 0) has the same effect.
    def render_primary_navigation(options = {})
      ActiveSupport::Deprecation.warn("SimpleNavigation::Helpers.render_primary_navigation has been deprected. Please use render_navigation(:level => 1) instead")
      render_navigation(options.merge(:level => 1))
    end

    # Deprecated. Renders the sub_navigation with the configured renderer. Calling render_navigation(:level => 1) has the same effect.
    def render_sub_navigation(options = {})
      ActiveSupport::Deprecation.warn("SimpleNavigation::Helpers.render_primary_navigation has been deprected. Please use render_navigation(:level => 2) instead")
      render_navigation(options.merge(:level => 2))
    end

    private

    def extract_backwards_compatible_options(*args)
      case args.first
        when Hash
          options = args.first
          options[:level] = 1 if options[:level] == :primary
          options[:level] = 2 if options[:level] == :secondary
        when Symbol
          raise ArgumentError, "Invalid arguments" unless [:primary, :secondary, :nested].include? args.first
          options = Hash.new
          options[:level] = args.first
          options[:level] = 1 if options[:level] == :primary
          options[:level] = 2 if options[:level] == :secondary
          options.merge!(args[1] || {})
        else
          raise ArgumentError, "Invalid arguments"
      end
      options
    end

  end
end