=begin
Streets Example

We load german cities from wikipedia and parse the document for cities and countries(states).
Further we load a collection of popular streetnames from a web-side called »strassen-in-deutschland«

We define three vertices, State, City and Street.
These are filled with the data from the web-sides

Then we connect the cities through streets just by creating edges.
At last we print the connected cities.

=end
module DataImport
  def read_german_street_names
    doc = Nokogiri::HTML(open('http://www.strassen-in-deutschland.de/die-haeufigsten-strassennamen-in-deutschland.html'))
    strassen = doc.css("td[data-header='Straßenname: '] a") # identified via css-inspector in browser
    # search for the css and include only links, then display the text-part
    strassen.children.map( &:to_s )[3..-1]  # omit the first three (strassen in deutschland, straßenverzeichnis, straßen)
  end

  def read_german_cities_from_wikipedia
    # we extract <li> -elements and use the text until "("
    #doc.xpath("//li").at(80)
    # => #<Nokogiri::XML::Element:0x1ba551c name="li" children=[#<Nokogiri::XML::Element:0x1ba533c name="a" attributes=[#<Nokogiri::XML::Attr:0x1ba52d8 name="href" value="/wiki/Angerm%C3%BCnde">, #<Nokogiri::XML::Attr:0x1ba52c4 name="title" value="Angermünde">] children=[#<Nokogiri::XML::Text:0x1ba4c84 "Angermünde">]>, #<Nokogiri::XML::Text:0x1ba4ae0 " (Brandenburg)">]>

    doc = Nokogiri::HTML(open('https://en.wikipedia.org/wiki/List_of_cities_and_towns_in_Germany'))
    print doc
    doc.xpath("//li").map{|x| x.text[0 .. x.text.index('(')-2] if x.text.index('(').present? }.compact
  end

  def read_german_cities_and_states_from_wikipedia
    doc =
    Nokogiri::HTML(open('https://en.wikipedia.org/wiki/List_of_cities_and_towns_in_Germany'))
    doc.xpath("//li").map do |x|
      if x.text.index('(').present?
        [ x.text[0 .. x.text.index('(')-2] , x.text[ x.text.index('(')+1 .. x.text.index(')')-1] ]
      end
    end.compact
  end

end # module

class StreetExample

  include  DataImport
  def initialize db, rebuild: true
    if rebuild
      db.delete_class :State
      db.delete_class :City
      db.delete_class :Street
      db.delete_class :CONNECTS
      db.create_vertex_class :State
      db.create_vertex_class :City
      db.create_vertex_class :Street
      db.create_edge_class :CONNECTS
      ActiveOrient::Model::State.create_property( :name, type: :string, index: :unique )
      ActiveOrient::Model::City.create_properties(  { name: { type: :string },
      state: { type: :link, :linked_class => 'State' } }
      ) do
        { citi_idx: :unique }
      end
      ActiveOrient::Model::Street.create_property :name , type: :string, index: :notunique
      ActiveOrient::Model::CONNECTS.create_property :distance, type: :integer, index: :notunique
      ActiveOrient::OrientDB.logger.progname = "StreetsExample#Initialize"
      ActiveOrient::OrientDB.logger.info { "Vertex- and Edge-Classes rebuilded" }
    end
  end


  def read_from_web
    read_german_cities_and_states_from_wikipedia.each do |city,state|
      state =  State.update_or_create( where: { name: state }).first
      City.create name: city, state: "##{state.rid}"
    end
    ActiveOrient::OrientDB.logger.progname = "StreetsExample#ReadFromWeb"
    ActiveOrient::OrientDB.logger.info { "#{City.count} Cities imported from Wikipedia " }

    cities_rids =  City.all.map &:rid
    read_german_street_names.each_with_index do |street, i|
      street_record =  Street.create name: street
      count = i
      cities =  Array.new
      while  count < cities_rids.size && cities.size < 5 do
        cities << cities_rids[count]
        count =  count + i
      end
      C.create_edge :from => street_record,  :to => cities
    end
    ActiveOrient::OrientDB.logger.progname = "StreetsExample#ReadFromWeb"
    ActiveOrient::OrientDB.logger.info { "#{C.count} Edges between Streets and Cities created " }
  end

  def display_streets_per_state
    State.all.each do |state|
      streets= Street.all.map do |street |
        if street.connects.in.detect{|x| x.state == state }
          street.name + " connects " + street.connects.in.map( &:name ).join('; ')
        end
      end.compact
      unless streets.empty?
        puts "..................................."
        puts state.name
        puts "..................................."
        puts streets.join("\n")
      end
    end
  end
end

if $0 == __FILE__

  require '../config/boot'
  require 'open-uri'
  require 'nokogiri'

  ActiveOrient::OrientDB.default_server= { user: 'root', password: 'tretretre' }
  r = ActiveOrient::OrientDB.new database: 'StreetTest'
  ActiveOrient::OrientDB.logger.level = Logger::INFO
  s= StreetExample.new r, rebuild:  true

  City = r.open_class :City
  State = r.open_class :State
  Street = r.open_class :Street
  C = r.open_class :CONNECTS

  s.read_from_web if City.count.zero?
  s.display_streets_per_state

end