require "active_support"

module Workflower
  mattr_accessor :workflower_state_column_name, :default_workflow_id
  module ActsAsWorkflower
    extend ActiveSupport::Concern

    module InstanceMethods
      # mattr_accessor :workflower_base
      attr_accessor :possible_events, :allowed_events, :allowed_transitions, :workflow_transition_event_name, :workflow_transition_flow

      def set_initial_state
        write_attribute self.class.workflower_state_column_name, workflower_initial_state
      end

      def workflower_initial_state
        workflower_base.set_initial_state
      end

      def workflower_base
        @workflower_base
      end

      def source_workflow
        @source_workflow_instance ||= source.new(self)
        @source_workflow_instance.get_workflows_for_workflow_id(workflow_id)
      end

      def workflower_initializer
        @source_workflow_instance ||= source.new(self)

        @workflower_base ||= Workflower::Manager.new(self, @source_workflow_instance)

        @workflower_base.allowed_transitions.each do |flow|
          define_singleton_method flow.trigger_action_name.to_s do
            @workflow_transition_event_name = flow.event
            @workflow_transition_flow = flow
            @workflower_base.process_transition!(flow)
          end

          define_singleton_method flow.boolean_action_name.to_s do
            @workflower_base.transition_possible?(flow)
          end
        end

        @possible_events     ||= @workflower_base.events
        @allowed_events      ||= @workflower_base.allowed_events
        @allowed_transitions ||= @workflower_base.allowed_transitions
      end

      def workflower_uninitializer(reset_source_workflow_instance: false)
        @workflower_base.uninitialize
        @workflower_base = nil

        @source_workflow_instance = nil if reset_source_workflow_instance
        @possible_events     = nil
        @allowed_events      = nil
        @allowed_transitions = nil
      end

      def initialize(*)
        super
        write_attribute :workflow_id, default_workflow_id if workflow_id.blank?

        workflower_initializer
      end
    end

    module ClassMethods
      def workflower(default_workflow_id:, source:, workflower_state_column_name: "workflow_state", skip_setting_initial_state: false)
        raise Workflower::WorkflowerError, "Options can't be blank" if source.blank? || default_workflow_id.blank?

        cattr_accessor :source,                       default: source
        cattr_accessor :workflower_state_column_name, default: workflower_state_column_name
        cattr_accessor :default_workflow_id,          default: default_workflow_id

        self.workflower_state_column_name = workflower_state_column_name
        self.source                       = source
        self.default_workflow_id          = default_workflow_id

        # self.validates  "#{workflow_model.tableize.singularize}_id", presence: true
        before_create :set_initial_state unless skip_setting_initial_state
      end

      def workflower_abilities(workflow_selector: nil)
        # workflow_selector helps dynamic transition selection when we have multiple workflows that needs to change depending on the workflow_selector.
        load = source.new(new).get_workflows.values.flatten.uniq unless workflow_selector.present?
        load = source.new(workflow_selector.to_sym).get_workflows.values.flatten.uniq if workflow_selector.present? 

        unless load.blank?
          # transitions = load.transitions.where("(metadata->>'roles') IS NOT NULL")
          transitions = load.select { |item| item.try(:[], :metadata).try(:key?, :roles) }

          roles = transitions.map { |item| item[:metadata][:roles] }.flatten.uniq

          roles_hash = {}

          roles.each do |role|
            roles_hash[role] = transitions.select { |trans| trans[:metadata][:roles].to_a.include?(role) }.map { |item| item[:event] }.uniq
          end

          roles_hash
        end
      end
    end

    def self.included(base)
      base.send :include, InstanceMethods
      base.extend(ClassMethods)
    end
  end
end