module Graphml2Json

# File lib/graphml2json.rb, line 6
def self.generate(xml_string)
  doc = Nokogiri::XML(xml_string)
  doc.remove_namespaces!
  graph = doc.xpath('//graph')
  nodes = graph.xpath('//node')
  edges = graph.xpath('//edge')

  @mapping = {}
  @json_nodes = []

  @graph = {}
  @graph[:nodes] = []
  @graph[:edges] = []

  nodes.each_with_index do |n, index|

    attributes = data_attributes(n)
    @mapping[n[:id]] = index
    new_node = {:name => index}.merge(attributes)
    @graph[:nodes] << new_node
  end

  @json_edges = []
  edges.each do |e|
    source = @mapping[e[:source]]
    target = @mapping[e[:target]]
    attributes = data_attributes(e)
    new_edge = { :source => source, :target => target }.merge(attributes)
    @graph[:edges] << new_edge
  end

  JSON.generate(@graph)
end

# File lib/graphml2json.rb, line 42
def self.data_attributes(node)
  data_nodes = node.xpath('./data')

  attributes = data_nodes.map do |d|
    {d[:key] => d.text}
  end.inject(&:merge)

  attributes || {}
end