dodgerogers/nucleus-core

module NucleusCore
  module Workflow
    class Graph
      INITIAL_STATE = :initial

      attr_reader :nodes, :execution

      def initialize(opts={})
        @nodes = {}
        @execution = opts.fetch(:execution, :default)

        define
      end

      def chain_of_command?
        execution == :chain_of_command
      end

      def define
        raise NotImplementedError, "Subclasses must implement the define method"
      end

      def start_node(signals={})
        add_node(state: INITIAL_STATE, signals: signals)
      end

      def add_node(node_attrs={})
        state = node_attrs[:state]
        raise ArgumentError, "state #{state} is already defined" if nodes.key?(state)

        NucleusCore::Workflow::Node.new(node_attrs).tap do |node|
          nodes[node.state] = node
        end
      end

      def fetch_node(state)
        nodes[state]
      end

      def self.call(signal: nil, process: nil, context: nil)
        manager = NucleusCore::Workflow::Manager.new(process: process, context: context, graph: new)
        manager.call(signal)
        manager
      end

      def self.rollback(process:, context:)
        manager = NucleusCore::Workflow::Manager.new(process: process, context: context, graph: new)
        manager.rollback
        manager
      end
    end
  end
end