Elixir module for persisting a list of Rhea SolarSystem structs into Neo4j

map_graph.ex

defmodule GalaxyMap.Importers.MapGraph do
  @moduledoc """
  Responsible for building the game map within Neo4j
  - Creates each solar system within Neo4j
  - Builds relationships between solar system nodes within Neo4j
  """
  def run(solar_systems) do
    solar_systems
    |> Enum.map(fn(system) -> persist_system(system) end)
    |> Enum.map(fn(system) -> build_connections(system) end)
    |> Enum.filter(fn(system_query) -> system_query != nil end)
    |> Enum.map(fn(system_query) -> execute_query(system_query) end)
  end

  def clear_graph_data do
    execute_query("MATCH (n) DETACH DELETE n")
  end

  defp persist_system(system) do
    execute_query(persist_system_query(system))
    system
  end

  defp persist_system_query(system) do
    "CREATE (s:SolarSystem:#{system.name} \
    { id: \"#{system.id}\", name: '#{system.name}',\
    x: #{system.x}, y: #{system.y}, import_id: #{system.import_id},\
    parent: #{system.parent}})"
  end

  defp neo4j_client do
    Bolt.Sips.conn()
  end

  defp execute_query(query) do
    Bolt.Sips.query!(neo4j_client(), query)
  end

  def build_connections(system) do
    case system.import_id do
      0    -> nil
      2000 -> nil
         _ ->
             "MATCH (o:SolarSystem),(d:SolarSystem) \
              WHERE o.import_id = #{system.import_id} AND d.import_id = #{system.parent} \
              WITH o, d \
              CREATE (o)-[x:Gate]->(d) \
              WITH d, o \
              CREATE (d)-[y:Gate]->(o) \
              RETURN o, d;"
    end

  end
end