module Crumbs
  module ActionController
    module Base
      extend ActiveSupport::Concern

      included do
        before_filter :define_crumbs
      end

      protected    

      def define_crumbs    
        check_referer
        parts = request.path.split('/')
        parts.pop unless Rails.application.config.crumbs.show_last
        @crumbs = []
        while parts.size > 0
          path = join_parts(parts)
          if params = find_path_params(path)
            if name = History.get_name(params[:controller], params[:action], params)
              if index = in_referer?(path)
                path = session[:referer][index][:fullpath]
              end 
              @crumbs << { name: name, path: path }   
            end
          end       
          parts.pop      
        end  
        @crumbs.reverse!  
      end

      def find_path_params(path)
        begin
          Rails.application.routes.recognize_path(request.base_url + path) 
        rescue
          false
        end
      end

      def check_referer
        if session[:referer].nil?
          reset_referer
        elsif is_last_referer?
          last_index = session[:referer].size - 1
          session[:referer][last_index][:fullpath] = request.fullpath
        elsif add_to_referer?
          add_to_referer
        elsif index = in_referer_tree?
          session[:referer] = session[:referer].slice(Range.new(0, index))
          add_to_referer
        else
          reset_referer
        end  
      end

      def add_to_referer
        session[:referer] << { base_url: request.base_url, path: request.path, fullpath: request.fullpath }
      end

      def reset_referer
        session[:referer] = [{ base_url: request.base_url, path: request.path, fullpath: request.fullpath }]   
      end
      
      def join_parts(parts)
        path = parts.join('/')
        (path[0] != '/' ? "/#{path}" : path)
      end
    
      def is_last_referer?
        last = session[:referer].last
        last[:base_url] == request.base_url and last[:path] == request.path
      end

      def add_to_referer?   
        last = session[:referer].last
        parts = request.path.split('/')
        parts.size > 0 and last[:path] == join_parts(parts.slice(0, parts.size - 1))
      end

      def in_referer?(path)
        find_in_referer path
      end

      def in_referer_tree?
        parts = request.path.split('/')
        parts.pop
        while parts.size > 0
          index = find_in_referer_tree(parts)            
          return index unless index.nil?
          parts.pop
        end
      end

      def find_in_referer(path)
        session[:referer].index do |referer|
          referer[:base_url] == request.base_url and referer[:path] == path
        end
      end         

      def find_in_referer_tree(parts)
        session[:referer].index do |referer|
          referer[:base_url] == request.base_url and 
          referer[:path] == join_parts(parts) and
          referer[:path] != request.path
        end
      end

      module ClassMethods
        
        protected
        
        def crumb(action, name)
          controller = self.name.gsub('::', '/').gsub('Controller', '').underscore
          History.add(controller, action, name)
        end
        
      end
    end
  end
end