module Answers
  class Plugin

    attr_accessor :name, :class_name, :controller, :directory, :url,
                  :dashboard, :always_allow_access, :menu_match,
                  :hide_from_menu, :pathname, :plugin_activity

    def self.register(&block)
      yield(plugin = self.new)

      raise "A plugin MUST have a name!: #{plugin.inspect}" if plugin.name.blank?

      # Set defaults.
      plugin.menu_match ||= %r{answers/#{plugin.name}(/.+?)?$}
      plugin.always_allow_access ||= false
      plugin.dashboard ||= false
      plugin.class_name ||= plugin.name.camelize

      # add the new plugin to the collection of registered plugins
      ::Answers::Plugins.registered << plugin
    end

    # Returns the internationalized version of the title
    def title
      ::I18n.translate(['answers', 'plugins', name, 'title'].join('.'))
    end

    # Returns the internationalized version of the description
    def description
      ::I18n.translate(['answers', 'plugins', name, 'description'].join('.'))
    end

    # Stores information that can be used to retrieve the latest activities of this plugin
    def activity=(activities)
      Answers.deprecate('Answers::Plugin#activity=', when: '3.1')
    end

    # Used to highlight the current tab in the admin interface
    def highlighted?(params)
      !!(params[:controller].try(:gsub, "admin/", "") =~ menu_match) || (dashboard && params[:action] == 'error_404')
    end

    def pathname=(value)
      value = Pathname.new(value) if value.is_a? String
      @pathname = value
    end

    # Returns a hash that can be used to create a url that points to the administration part of the plugin.
    def url
      @url ||= if controller.present?
        { :controller => "answers/admin/#{controller}" }
      elsif directory.present?
        { :controller => "answers/admin/#{directory.split('/').pop}" }
      else
        { :controller => "answers/admin/#{name}" }
      end

      if @url.is_a?(Hash)
        {:only_path => true}.merge(@url)
      elsif @url.respond_to?(:call)
        @url.call
      else
        @url
      end
    end

    # Make this protected, so that only Plugin.register can use it.
    protected
    def initialize
      # provide a default pathname to where this plugin is using its lib directory.
      depth = RUBY_VERSION >= "1.9.2" ? 4 : 3
      self.pathname ||= Pathname.new(caller(depth).first.match("(.*)#{File::SEPARATOR}lib")[1])
    end
  end
end