/* jshint maxlen:160 */
'use strict';

////////////////////////////////////////////////////////////////////////////////
/// @brief Graph Data for Example
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2014 triagens GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Michael Hackstein
/// @author Copyright 2011-2014, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

var Graph = require("@arangodb/general-graph");
var db = require("internal").db;

var arangodb = require("@arangodb");
var ArangoError = arangodb.ArangoError;

// we create a graph with 'knows' pointing from 'persons' to 'persons'
var createTraversalExample = function() {
  var g = Graph._create("knows_graph",
    [Graph._relation("knows", "persons", "persons")]
  );
  var a = g.persons.save({name: "Alice", _key: "alice"})._id;
  var b = g.persons.save({name: "Bob", _key: "bob"})._id;
  var c = g.persons.save({name: "Charlie", _key: "charlie"})._id;
  var d = g.persons.save({name: "Dave", _key: "dave"})._id;
  var e = g.persons.save({name: "Eve", _key: "eve"})._id;
  g.knows.save(a, b, {});
  g.knows.save(b, c, {});
  g.knows.save(b, d, {});
  g.knows.save(e, a, {});
  g.knows.save(e, b, {});
  return g;
};

// we create a graph with 'relation' pointing from 'female' to 'male' and 'male
var createSocialGraph = function() {
  var edgeDefinition = [];
  edgeDefinition.push(Graph._relation("relation", ["female", "male"], ["female", "male"]));
  var g = Graph._create("social", edgeDefinition);
  var a = g.female.save({name: "Alice", _key: "alice"});
  var b = g.male.save({name: "Bob", _key: "bob"});
  var c = g.male.save({name: "Charly", _key: "charly"});
  var d = g.female.save({name: "Diana", _key: "diana"});
  g.relation.save(a._id, b._id, {type: "married", _key: "aliceAndBob"});
  g.relation.save(a._id, c._id, {type: "friend", _key: "aliceAndCharly"});
  g.relation.save(c._id, d._id, {type: "married", _key: "charlyAndDiana"});
  g.relation.save(b._id, d._id, {type: "friend", _key: "bobAndDiana"});
  return g;
};

var createRoutePlannerGraph = function() {
  var edgeDefinition = [];
  edgeDefinition.push(Graph._relation(
    "germanHighway", ["germanCity"], ["germanCity"])
  );
  edgeDefinition.push(
    Graph._relation("frenchHighway", ["frenchCity"], ["frenchCity"])
  );
  edgeDefinition.push(Graph._relation(
    "internationalHighway", ["frenchCity", "germanCity"], ["frenchCity", "germanCity"])
  );

  var g = Graph._create("routeplanner", edgeDefinition);
  var berlin = g.germanCity.save({_key: "Berlin", population : 3000000, isCapital : true, loc: [52.5167, 13.3833]});
  var cologne = g.germanCity.save({_key: "Cologne", population : 1000000, isCapital : false, loc: [50.9364, 6.9528]});
  var hamburg = g.germanCity.save({_key: "Hamburg", population : 1000000, isCapital : false, loc: [53.5653, 10.0014]});
  var lyon = g.frenchCity.save({_key: "Lyon", population : 80000, isCapital : false, loc: [45.7600, 4.8400]});
  var paris = g.frenchCity.save({_key: "Paris", population : 4000000, isCapital : true, loc: [48.8567, 2.3508]});
  g.germanCity.ensureGeoIndex("loc");
  g.frenchCity.ensureGeoIndex("loc");
  g.germanHighway.save(berlin._id, cologne._id, {distance: 850});
  g.germanHighway.save(berlin._id, hamburg._id, {distance: 400});
  g.germanHighway.save(hamburg._id, cologne._id, {distance: 500});
  g.frenchHighway.save(paris._id, lyon._id, {distance: 550});
  g.internationalHighway.save(berlin._id, lyon._id, {distance: 1100});
  g.internationalHighway.save(berlin._id, paris._id, {distance: 1200});
  g.internationalHighway.save(hamburg._id, paris._id, {distance: 900});
  g.internationalHighway.save(hamburg._id, lyon._id, {distance: 1300});
  g.internationalHighway.save(cologne._id, lyon._id, {distance: 700});
  g.internationalHighway.save(cologne._id, paris._id, {distance: 550});
  return g;
};

var saveWorldCountryGraphData = function() {
  // This example writes the graph data without using the general graph interface.
  // it expects to find the collections to be already created.
  // It can be called either via createWorldCountryGraph() that will create a managed graph
  // or via dropWorldCountryUnManaged that will simply generate a set of vertex and edge collections.
  // instead of using 
  //    var world  = worldCountryGraph.worldVertices.save({ _key: "world", name: "World", type: "root" });
  //    var africa = worldCountryGraph.worldVertices.save({ _key: "continent-africa", name: "Africa", type: "continent" });
  //    worldCountryGraph.worldEdges.save(world._id, africa._id, { type: "is-in" });
  //
  // we will directly put the documents into their respective collections
  // and have to ensure graph consistency by ourselves.

  // vertices: root node 
  var db = require("internal").db;
  db.worldVertices.save({ _key: "world", name: "World", type: "root" });

  // vertices: continents 
  db.worldVertices.save({ _key: "continent-africa", name: "Africa", type: "continent" });
  db.worldVertices.save({ _key: "continent-asia", name: "Asia", type: "continent" });
  db.worldVertices.save({ _key: "continent-australia", name: "Australia", type: "continent" });
  db.worldVertices.save({ _key: "continent-europe", name: "Europe", type: "continent" });
  db.worldVertices.save({ _key: "continent-north-america", name: "North America", type: "continent" });
  db.worldVertices.save({ _key: "continent-south-america", name: "South America", type: "continent" });

  // vertices: countries 
  db.worldVertices.save({ _key: "country-afghanistan", name: "Afghanistan", type: "country", code: "AFG" });
  db.worldVertices.save({ _key: "country-albania", name: "Albania", type: "country", code: "ALB" });
  db.worldVertices.save({ _key: "country-algeria", name: "Algeria", type: "country", code: "DZA" });
  db.worldVertices.save({ _key: "country-andorra", name: "Andorra", type: "country", code: "AND" });
  db.worldVertices.save({ _key: "country-angola", name: "Angola", type: "country", code: "AGO" });
  db.worldVertices.save({ _key: "country-antigua-and-barbuda", name: "Antigua and Barbuda", type: "country", code: "ATG" });
  db.worldVertices.save({ _key: "country-argentina", name: "Argentina", type: "country", code: "ARG" });
  db.worldVertices.save({ _key: "country-australia", name: "Australia", type: "country", code: "AUS" });
  db.worldVertices.save({ _key: "country-austria", name: "Austria", type: "country", code: "AUT" });
  db.worldVertices.save({ _key: "country-bahamas", name: "Bahamas", type: "country", code: "BHS" });
  db.worldVertices.save({ _key: "country-bahrain", name: "Bahrain", type: "country", code: "BHR" });
  db.worldVertices.save({ _key: "country-bangladesh", name: "Bangladesh", type: "country", code: "BGD" });
  db.worldVertices.save({ _key: "country-barbados", name: "Barbados", type: "country", code: "BRB" });
  db.worldVertices.save({ _key: "country-belgium", name: "Belgium", type: "country", code: "BEL" });
  db.worldVertices.save({ _key: "country-bhutan", name: "Bhutan", type: "country", code: "BTN" });
  db.worldVertices.save({ _key: "country-bolivia", name: "Bolivia", type: "country", code: "BOL" });
  db.worldVertices.save({ _key: "country-bosnia-and-herzegovina", name: "Bosnia and Herzegovina", type: "country", code: "BIH" });
  db.worldVertices.save({ _key: "country-botswana", name: "Botswana", type: "country", code: "BWA" });
  db.worldVertices.save({ _key: "country-brazil", name: "Brazil", type: "country", code: "BRA" });
  db.worldVertices.save({ _key: "country-brunei", name: "Brunei", type: "country", code: "BRN" });
  db.worldVertices.save({ _key: "country-bulgaria", name: "Bulgaria", type: "country", code: "BGR" });
  db.worldVertices.save({ _key: "country-burkina-faso", name: "Burkina Faso", type: "country", code: "BFA" });
  db.worldVertices.save({ _key: "country-burundi", name: "Burundi", type: "country", code: "BDI" });
  db.worldVertices.save({ _key: "country-cambodia", name: "Cambodia", type: "country", code: "KHM" });
  db.worldVertices.save({ _key: "country-cameroon", name: "Cameroon", type: "country", code: "CMR" });
  db.worldVertices.save({ _key: "country-canada", name: "Canada", type: "country", code: "CAN" });
  db.worldVertices.save({ _key: "country-chad", name: "Chad", type: "country", code: "TCD" });
  db.worldVertices.save({ _key: "country-chile", name: "Chile", type: "country", code: "CHL" });
  db.worldVertices.save({ _key: "country-colombia", name: "Colombia", type: "country", code: "COL" });
  db.worldVertices.save({ _key: "country-cote-d-ivoire", name: "Cote d'Ivoire", type: "country", code: "CIV" });
  db.worldVertices.save({ _key: "country-croatia", name: "Croatia", type: "country", code: "HRV" });
  db.worldVertices.save({ _key: "country-czech-republic", name: "Czech Republic", type: "country", code: "CZE" });
  db.worldVertices.save({ _key: "country-denmark", name: "Denmark", type: "country", code: "DNK" });
  db.worldVertices.save({ _key: "country-ecuador", name: "Ecuador", type: "country", code: "ECU" });
  db.worldVertices.save({ _key: "country-egypt", name: "Egypt", type: "country", code: "EGY" });
  db.worldVertices.save({ _key: "country-eritrea", name: "Eritrea", type: "country", code: "ERI" });
  db.worldVertices.save({ _key: "country-finland", name: "Finland", type: "country", code: "FIN" });
  db.worldVertices.save({ _key: "country-france", name: "France", type: "country", code: "FRA" });
  db.worldVertices.save({ _key: "country-germany", name: "Germany", type: "country", code: "DEU" });
  db.worldVertices.save({ _key: "country-people-s-republic-of-china", name: "People's Republic of China", type: "country", code: "CHN" });

  // vertices: capitals 
  db.worldVertices.save({ _key: "capital-algiers", name: "Algiers", type: "capital" });
  db.worldVertices.save({ _key: "capital-andorra-la-vella", name: "Andorra la Vella", type: "capital" });
  db.worldVertices.save({ _key: "capital-asmara", name: "Asmara", type: "capital" });
  db.worldVertices.save({ _key: "capital-bandar-seri-begawan", name: "Bandar Seri Begawan", type: "capital" });
  db.worldVertices.save({ _key: "capital-beijing", name: "Beijing", type: "capital" });
  db.worldVertices.save({ _key: "capital-berlin", name: "Berlin", type: "capital" });
  db.worldVertices.save({ _key: "capital-bogota", name: "Bogota", type: "capital" });
  db.worldVertices.save({ _key: "capital-brasilia", name: "Brasilia", type: "capital" });
  db.worldVertices.save({ _key: "capital-bridgetown", name: "Bridgetown", type: "capital" });
  db.worldVertices.save({ _key: "capital-brussels", name: "Brussels", type: "capital" });
  db.worldVertices.save({ _key: "capital-buenos-aires", name: "Buenos Aires", type: "capital" });
  db.worldVertices.save({ _key: "capital-bujumbura", name: "Bujumbura", type: "capital" });
  db.worldVertices.save({ _key: "capital-cairo", name: "Cairo", type: "capital" });
  db.worldVertices.save({ _key: "capital-canberra", name: "Canberra", type: "capital" });
  db.worldVertices.save({ _key: "capital-copenhagen", name: "Copenhagen", type: "capital" });
  db.worldVertices.save({ _key: "capital-dhaka", name: "Dhaka", type: "capital" });
  db.worldVertices.save({ _key: "capital-gaborone", name: "Gaborone", type: "capital" });
  db.worldVertices.save({ _key: "capital-helsinki", name: "Helsinki", type: "capital" });
  db.worldVertices.save({ _key: "capital-kabul", name: "Kabul", type: "capital" });
  db.worldVertices.save({ _key: "capital-la-paz", name: "La Paz", type: "capital" });
  db.worldVertices.save({ _key: "capital-luanda", name: "Luanda", type: "capital" });
  db.worldVertices.save({ _key: "capital-manama", name: "Manama", type: "capital" });
  db.worldVertices.save({ _key: "capital-nassau", name: "Nassau", type: "capital" });
  db.worldVertices.save({ _key: "capital-n-djamena", name: "N'Djamena", type: "capital" });
  db.worldVertices.save({ _key: "capital-ottawa", name: "Ottawa", type: "capital" });
  db.worldVertices.save({ _key: "capital-ouagadougou", name: "Ouagadougou", type: "capital" });
  db.worldVertices.save({ _key: "capital-paris", name: "Paris", type: "capital" });
  db.worldVertices.save({ _key: "capital-phnom-penh", name: "Phnom Penh", type: "capital" });
  db.worldVertices.save({ _key: "capital-prague", name: "Prague", type: "capital" });
  db.worldVertices.save({ _key: "capital-quito", name: "Quito", type: "capital" });
  db.worldVertices.save({ _key: "capital-saint-john-s", name: "Saint John's", type: "capital" });
  db.worldVertices.save({ _key: "capital-santiago", name: "Santiago", type: "capital" });
  db.worldVertices.save({ _key: "capital-sarajevo", name: "Sarajevo", type: "capital" });
  db.worldVertices.save({ _key: "capital-sofia", name: "Sofia", type: "capital" });
  db.worldVertices.save({ _key: "capital-thimphu", name: "Thimphu", type: "capital" });
  db.worldVertices.save({ _key: "capital-tirana", name: "Tirana", type: "capital" });
  db.worldVertices.save({ _key: "capital-vienna", name: "Vienna", type: "capital" });
  db.worldVertices.save({ _key: "capital-yamoussoukro", name: "Yamoussoukro", type: "capital" });
  db.worldVertices.save({ _key: "capital-yaounde", name: "Yaounde", type: "capital" });
  db.worldVertices.save({ _key: "capital-zagreb", name: "Zagreb", type: "capital" });

  // edges: continent -> world 
  db.worldEdges.save("worldVertices/continent-africa", "worldVertices/world", { type: "is-in" });
  db.worldEdges.save("worldVertices/continent-asia", "worldVertices/world", { type: "is-in" });
  db.worldEdges.save("worldVertices/continent-australia", "worldVertices/world", { type: "is-in" });
  db.worldEdges.save("worldVertices/continent-europe", "worldVertices/world", { type: "is-in" });
  db.worldEdges.save("worldVertices/continent-north-america", "worldVertices/world", { type: "is-in" });
  db.worldEdges.save("worldVertices/continent-south-america", "worldVertices/world", { type: "is-in" });

  // edges: country -> continent 
  db.worldEdges.save("worldVertices/country-afghanistan", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-albania", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-algeria", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-andorra", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-angola", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-antigua-and-barbuda", "worldVertices/continent-north-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-argentina", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-australia", "worldVertices/continent-australia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-austria", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bahamas", "worldVertices/continent-north-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bahrain", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bangladesh", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-barbados", "worldVertices/continent-north-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-belgium", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bhutan", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bolivia", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bosnia-and-herzegovina", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-botswana", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-brazil", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-brunei", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-bulgaria", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-burkina-faso", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-burundi", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-cambodia", "worldVertices/continent-asia", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-cameroon", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-canada", "worldVertices/continent-north-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-chad", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-chile", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-colombia", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-cote-d-ivoire", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-croatia", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-czech-republic", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-denmark", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-ecuador", "worldVertices/continent-south-america", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-egypt", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-eritrea", "worldVertices/continent-africa", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-finland", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-france", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-germany", "worldVertices/continent-europe", { type: "is-in" });
  db.worldEdges.save("worldVertices/country-people-s-republic-of-china", "worldVertices/continent-asia", { type: "is-in" });

  // edges: capital -> country 
  db.worldEdges.save("worldVertices/capital-algiers", "worldVertices/country-algeria", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-andorra-la-vella", "worldVertices/country-andorra", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-asmara", "worldVertices/country-eritrea", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-bandar-seri-begawan", "worldVertices/country-brunei", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-beijing", "worldVertices/country-people-s-republic-of-china", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-berlin", "worldVertices/country-germany", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-bogota", "worldVertices/country-colombia", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-brasilia", "worldVertices/country-brazil", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-bridgetown", "worldVertices/country-barbados", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-brussels", "worldVertices/country-belgium", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-buenos-aires", "worldVertices/country-argentina", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-bujumbura", "worldVertices/country-burundi", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-cairo", "worldVertices/country-egypt", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-canberra", "worldVertices/country-australia", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-copenhagen", "worldVertices/country-denmark", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-dhaka", "worldVertices/country-bangladesh", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-gaborone", "worldVertices/country-botswana", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-helsinki", "worldVertices/country-finland", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-kabul", "worldVertices/country-afghanistan", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-la-paz", "worldVertices/country-bolivia", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-luanda", "worldVertices/country-angola", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-manama", "worldVertices/country-bahrain", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-nassau", "worldVertices/country-bahamas", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-n-djamena", "worldVertices/country-chad", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-ottawa", "worldVertices/country-canada", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-ouagadougou", "worldVertices/country-burkina-faso", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-paris", "worldVertices/country-france", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-phnom-penh", "worldVertices/country-cambodia", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-prague", "worldVertices/country-czech-republic", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-quito", "worldVertices/country-ecuador", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-saint-john-s", "worldVertices/country-antigua-and-barbuda", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-santiago", "worldVertices/country-chile", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-sarajevo", "worldVertices/country-bosnia-and-herzegovina", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-sofia", "worldVertices/country-bulgaria", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-thimphu", "worldVertices/country-bhutan", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-tirana", "worldVertices/country-albania", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-vienna", "worldVertices/country-austria", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-yamoussoukro", "worldVertices/country-cote-d-ivoire", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-yaounde", "worldVertices/country-cameroon", { type: "is-in" });
  db.worldEdges.save("worldVertices/capital-zagreb", "worldVertices/country-croatia", { type: "is-in" });
};

var createWorldCountryGraph = function() {

  // Here we use the graph module to create the collections for the world example:
/* jshint ignore:start */
  var worldCountryGraph = Graph._create("worldCountry",
                                        [Graph._relation("worldEdges", ["worldVertices"], ["worldVertices"])]
                                       );
/* jshint ignore:end */
  // and load the data of the graph into the collections created by the graph module:
  saveWorldCountryGraphData();
};

var createWorldCountryGraphUnManaged = function() {
  // if we don't manage the graph, we need to drop the vertex/edge collections manually.
  var db = require("internal").db;
  db._create("worldVertices");
  db._createEdgeCollection("worldEdges");
  saveWorldCountryGraphData();
};

var dropWorldCountryUnManaged = function() {

  // here we just use flat vertex/edge collections
  var db = require("internal").db;
  db._drop("worldVertices");
  db._drop("worldEdges");
};


var createTraversalGraph = function() {
    var graph_module = require("@arangodb/general-graph");
    
    var graph = graph_module._create("traversalGraph", [
        graph_module._relation("edges", "circles", ["circles"])]);
    
    // Add circle circles
    graph.circles.save({"_key": "A", "label":  '1'});
    graph.circles.save({"_key": "B", "label":  '2'});
    graph.circles.save({"_key": "C", "label":  '3'});
    graph.circles.save({"_key": "D", "label":  '4'});
    graph.circles.save({"_key": "E", "label":  '5'});
    graph.circles.save({"_key": "F", "label":  '6'});
    graph.circles.save({"_key": "G", "label":  '7'});
    graph.circles.save({"_key": "H", "label":  '8'});
    graph.circles.save({"_key": "I", "label":  '9'});
    graph.circles.save({"_key": "J", "label": '10'});
    graph.circles.save({"_key": "K", "label": '11'});
   
    // Add relevant edges - left branch:
    graph.edges.save("circles/A", "circles/B", {theFalse: false, theTruth: true, "label": 'left_bar'});
    graph.edges.save("circles/B", "circles/C", {theFalse: false, theTruth: true, "label": 'left_blarg'});
    graph.edges.save("circles/C", "circles/D", {theFalse: false, theTruth: true, "label": 'left_blorg'});
    graph.edges.save("circles/B", "circles/E", {theFalse: false, theTruth: true, "label": 'left_blub'});
    graph.edges.save("circles/E", "circles/F", {theFalse: false, theTruth: true, "label": 'left_schubi'});
    
    // Add relevant edges - right branch:
    graph.edges.save("circles/A", "circles/G", {theFalse: false, theTruth: true, "label": 'right_foo'});
    graph.edges.save("circles/G", "circles/H", {theFalse: false, theTruth: true, "label": 'right_blob'});
    graph.edges.save("circles/H", "circles/I", {theFalse: false, theTruth: true, "label": 'right_blub'});
    graph.edges.save("circles/G", "circles/J", {theFalse: false, theTruth: true, "label": 'right_zip'});
    graph.edges.save("circles/J", "circles/K", {theFalse: false, theTruth: true, "label": 'right_zup'});
};


var knownGraphs = {
  "knows_graph"           : {create: createTraversalExample, dependencies: [
    "knows", "persons"
  ]},
  "routeplanner"          : {create: createRoutePlannerGraph, dependencies: [
    "frenchHighway", "frenchCity", "germanCity", "germanHighway", "internationalHighway"
  ]},
  "social"                : {create: createSocialGraph, dependencies: [
    "relation", "female", "male"
  ]},
  "worldCountry"          : {create: createWorldCountryGraph, dependencies: [
    "worldVertices", "worldEdges"
  ]},
  "worldCountryUnManaged" : {create: createWorldCountryGraphUnManaged, dependencies: [
    "worldVertices", "worldEdges"
  ]},
  "traversalGraph"        : {create: createTraversalGraph, dependencies: [
    "edges", "circles"
  ]}
};

var unManagedGraphs = {
  "worldCountryUnManaged" : dropWorldCountryUnManaged
};

var dropGraph = function (name, prefixed) {

  if (! knownGraphs.hasOwnProperty(name)) {
    // trying to drop an unknown graph - better not do it
    return false;
  }
  if (unManagedGraphs.hasOwnProperty(name)) {
    unManagedGraphs[name]();
  }
  else {
    if (prefixed) {
      name = "UnitTest" + name;
    }
    if (Graph._exists(name)) {
      return Graph._drop(name, true);
    }
  }
};

var loadGraph = function (name, prefixed) {
  if (! knownGraphs.hasOwnProperty(name)) {
    // trying to drop an unknown graph - better not do it
    return false;
  }
  else {
    var collections = [];

    db._collections().forEach(function(c) {
      collections.push(c.name());
    });

    var dependencies = [];

    knownGraphs[name].dependencies.forEach(function(val) {
      collections.forEach(function (c) {
        if (val === c) {
          dependencies.push(val);
        }
      });
    });

    if (dependencies.length > 0) {
      var err = new ArangoError();
      err.errorNum = arangodb.ERROR_ARANGO_DUPLICATE_NAME;
      if (dependencies.loadGraph > 1) {
        err.errorMessage = "the collections: " + JSON.stringify(dependencies) + " already exist. Please clean up and try again.";
      }
      else {
        err.errorMessage = "the collection: " + JSON.stringify(dependencies) + " already exists. Please clean up and try again.";
      }
      throw err;
    }
  }

  dropGraph(name);
  return knownGraphs[name].create(prefixed);
};

exports.loadGraph = loadGraph;
exports.dropGraph = dropGraph;