module Wizard
  module Controller
    module Concerns
      module Steps
        extend ActiveSupport::Concern
        
        included do
          # Give our Views helper methods!
          helper_method :step,   :next_step,          :wizard_steps,     :current_step?,
                        :past_step?,      :future_step?,     :previous_step?,
                        :next_step?, :last_step?
        end
        
        module ClassMethods
          private
          
          def wizard_steps(*wizard_steps)
            const_set 'WIZARD_STEPS', wizard_steps
            
            # TODO: clarify if we still need to generate actions when we have an update action and next_step trigger
            "::#{self.to_s}::WIZARD_STEPS".constantize.each do |wizard_step|  
              next if wizard_step == :initialization
              
              define_method wizard_step do
                setup_wizard
                
                send("before_#{wizard_step}") if self.respond_to?("before_#{wizard_step}")
                
                wizard_resource = wizard_resource_class_name.constantize.find(params[:id])
                resource_name = wizard_resource_class_name.underscore
                resource.attributes = params[resource_name.to_sym] if params[resource_name.to_sym]
                
                if @story.send(next_step)
                  redirect_to eval("#{next_step}_#{resource_name}_path(resource)")
                else
                  send("after_#{wizard_step}") if self.respond_to?("after_#{wizard_step}")
                end
              end
            end
          end
          
          def wizard_step_per_state(hash)
            const_set 'WIZARD_STEP_PER_STATE', hash
          end
        end
      
        def wizard_steps
          "#{controller_class_name}::WIZARD_STEPS".constantize
        end
        
        def wizard_step_per_state
          "#{controller_class_name}::WIZARD_STEP_PER_STATE".constantize rescue {}
        end
        
        def wizard_resource_class_name
          controller_name.classify
        end
      
        def jump_to(goto_step)
          @skip_to = goto_step
        end
      
        def skip_step
          @skip_to = @next_step
        end
      
        def step
          @step
        end
      
        # will return true if step passed in is the currently rendered step
        def current_step?(step_name)
          return false if step_name.nil? || step.nil?
          
          step == step_name
        end
      
        # will return true if the step passed in has already been executed by the wizard
        def past_step?(step_name)
          return false if wizard_steps.index(step).nil? || wizard_steps.index(step_name).nil?
          
          wizard_steps.index(step) > wizard_steps.index(step_name)
        end
      
        # will return true if the step passed in has already been executed by the wizard
        def future_step?(step_name)
          return false if wizard_steps.index(step).nil? || wizard_steps.index(step_name).nil?
          
          wizard_steps.index(step) < wizard_steps.index(step_name)
        end
      
        # will return true if the last step is the step passed in
        def previous_step?(step_name)
          return false if wizard_steps.index(step).nil? || wizard_steps.index(step_name).nil?
          
          wizard_steps.index(step) - 1  == wizard_steps.index(step_name)
        end
      
        # will return true if the next step is the step passed in
        def next_step?(step_name)
          return false if wizard_steps.index(step).nil? || wizard_steps.index(step_name).nil?
          
          wizard_steps.index(step) + 1  == wizard_steps.index(step_name)
        end
       
        def previous_step(current_step = nil)
          return @previous_step if current_step == nil
          
          index =  wizard_steps.index(current_step)
          step  =  wizard_steps.at(index - 1) if index.present? && index != 0
          step ||= wizard_steps.first
          
          step
        end
      
        def next_step(current_step = nil)
          return @next_step if current_step == nil
          
          index = wizard_steps.index(current_step)
          step  = wizard_steps.at(index + 1) if index.present?
          step  ||= :finish
          
          step
        end
        
        def last_step?(current_step = nil)
          current_step = current_step || step
          
          current_step == wizard_steps.last
        end
        
        private
        
        def controller_class_name
          name = self.to_s.gsub(/#|<|>|#/, '').split(':').select{|e| !e.blank? }
          name.pop
          name.join('::')
        end
      end
    end
  end
end