module Petergate
  module ActionController
    module Base
      module ClassMethods
        def const_missing(const_name)
          if [:AllRest, :ALLREST].include?(const_name)
            warn "`AllRest` and `ALLREST` has been deprecated. Use :all instead."
            return ALLRESTDEP
          else
            return super 
          end
        end

        def all_actions
          ->{self.action_methods.to_a.map(&:to_sym) - [:check_access, :title]}.call
        end

        def except_actions(arr = [])
          all_actions - arr
        end

        def access(rules = {}, &block)
          if block
            b_rules = block.call
            rules = rules.merge(b_rules) if b_rules.is_a?(Hash)
          end

          instance_eval do
            @_controller_rules = rules
            @_controller_message = rules.delete(:message)

            def controller_rules
              @_controller_rules
            end

            def controller_message
              @_controller_message || "Permission Denied"
            end

            def inherited(subclass)
              super
              subclass.instance_variable_set("@_controller_rules", instance_variable_get("@_controller_rules"))
              subclass.instance_variable_set("@_controller_message", instance_variable_get("@_controller_message"))
            end
          end

          before_action do 
            unless logged_in?(:root_admin)
              message = permissions(self.class.controller_rules)
              if message == false || message.is_a?(String)
                if current_user || @user
                  forbidden! message
                else
                  unauthorized!
                end
              end
            end
          end
        end
      end

      ALLRESTDEP = [:show, :index, :new, :edit, :update, :create, :destroy]

      def self.included(base)
        base.extend(ClassMethods)
        base.helper_method :logged_in?, :forbidden!, :unauthorized!
      end

      def parse_permission_rules(rules)
        rules = rules.inject({}) do |h, (k, v)| 
          special_values = case v.class.to_s
                           when "Symbol"
                             v == :all ? self.class.all_actions : raise("No action for: #{v}")
                           when "Hash"
                             v[:except].present? ? self.class.except_actions(v[:except]) : raise("Invalid values for except: #{v.values}")
                           when "Array"
                             v
                           else
                             raise("No action for: #{v}")
                           end

          h.merge({k => special_values})
        end
        # Allows Array's of keys for the same hash.
        rules = rules.inject({}){|h, (k, v)| k.class == Array ? h.merge(Hash[k.map{|kk| [kk, v]}]) : h.merge(k => v) }
      end

      def permissions(rules = {all: [:index, :show], customer: [], wiring: []})
        rules = parse_permission_rules(rules)
        allowances = [rules[:all]]
        current_user.roles.each do |role|
          allowances << rules[role]
        end if user_logged_in? 
        allowances.flatten.compact.include?(action_name.to_sym)
      end

      def logged_in?(*roles)
        current_user && current_user.has_roles?(*roles)
      end

      def user_logged_in?
        !!current_user
      end

      def custom_message
        defined?(self.class.controller_message) ? self.class.controller_message : 'Permission Denied'
      end

      def unauthorized!
        respond_to do |format|
          format.any(:js, :json, :xml) do 
            head(:unauthorized)
          end
          format.html do
            return authenticate_user! 
          end
        end
      end

      def forbidden!(msg = nil)
        respond_to do |format|
          format.any(:js, :json, :xml) do 
            head(:forbidden)
          end
          format.html do
            destination = current_user.present? ? request.headers['Referrer'] || after_sign_in_path_for(current_user) : root_path
            redirect_to destination, notice: (msg || request.headers['msg'] || custom_message)
          end
        end
      end
    end
  end
end

class ActionController::Base
  include Petergate::ActionController::Base
end
