class RSpec::GraphRunner
  module Tg
    def all(usage_style = :read_write, indices = true, &block)
      tg(usage_style, indices, &block)
    end

    def tg(usage_style = :read_write, indices = true, &block)
      return unless use_graph? 'tg'
      describe 'tg' do
        let(:graph) do
          g = Pacer.tg
          unless indices
            g.drop_index :vertices
            g.drop_index :edges
          end
          g
        end
        let(:graph2) { Pacer.tg }
        instance_eval(&block)
      end
    end

    def dex(*args)
    end
  end

  module RubyGraph
    def all(usage_style = :read_write, indices = true, &block)
      super
      rg(usage_style, indices, &block)
    end

    def rg(usage_style = :read_write, indices = true, &block)
      for_graph('rg', usage_style, indices, false, ruby_graph, ruby_graph2, nil, block)
    end

    protected

    def ruby_graph
      Pacer::RubyGraph.new
    end

    def ruby_graph2
      Pacer::RubyGraph.new
    end
  end

  module MultiGraph
    def all(usage_style = :read_write, indices = true, &block)
      super
      multigraph(usage_style, indices, &block)
    end

    def multigraph(usage_style = :read_write, indices = true, &block)
      for_graph('multigraph', usage_style, indices, false, multi_graph, multi_graph2, nil, block)
    end

    protected

    def multi_graph
      Pacer::MultiGraph.new
    end

    def multi_graph2
      Pacer::MultiGraph.new
    end
  end

  include Tg
  include RubyGraph
  include MultiGraph

  def initialize(*graphs)
    @graphs = graphs.map { |s| s.to_s.downcase.split(/\s*,\s*/) }.flatten.map { |s| s.strip }.reject { |s| s == '' }
  end

  def inspect
    if @graphs.empty?
      "Testing all graphs."
    else
      "Testing graphs: #{ @graphs.join ', ' }."
    end
  end

  def use_graph?(name)
    if @graphs.empty?
      true
    else
      @graphs.include? name
    end
  end

protected

  def for_graph(name, usage_style, indices, transactions, source_graph_1, source_graph_2, unindexed_graph, block)
    return unless use_graph? name
    describe name do
      let(:graph) do
        if indices
          source_graph_1
        else
          unindexed_graph
        end
      end
      let(:graph2) do
        source_graph_2
      end
      if usage_style == :read_only
        before(:all) do
          source_graph_1.v.delete!
          source_graph_2.v.delete!
          unindexed_graph.v.delete! if unindexed_graph
        end
      end
      around do |spec|
        if usage_style == :read_write
          source_graph_1.v.delete!
          source_graph_2.v.delete!
          unindexed_graph.v.delete! if unindexed_graph
        end
        if transactions and spec.use_transactions?
          graph.manual_transactions do
            graph2.manual_transactions do
              begin
                graph.begin_transaction
                graph2.begin_transaction
                spec.run
              ensure
                graph.rollback_transaction rescue nil
                graph2.rollback_transaction rescue nil
              end
            end
          end
        else
          spec.run
        end
      end
      instance_eval(&block)
    end
  end
end