defmodule Exred.Library do
  @moduledoc """
  Library application for Exred. Handles storage and access of flows.
  """
  
  alias Exred.Library.DbProxy
  alias Exred.Library.Utils
  alias Exred.Library.Node
  alias Exred.Library.Connection

  @doc """
  Get all node instances from the database
  """
  def get_all_nodes do
    query_stm = "select id, name, category, module, config, flow_id from nodes where not is_prototype;"
    {:ok, result} = DbProxy.query query_stm, []

    # convert result from db to node struct
    Enum.map result.rows, fn([id, name, category, module, config, flow_id]) ->

      node_id = id |> UUID.binary_to_string! |> String.to_atom
      node_module = String.to_existing_atom module
      node_config = Utils.convert_to_atom_map config
      flow_id = flow_id |> UUID.binary_to_string! |> String.to_atom
      
      %Node{
        id: node_id,
        name: name,
        category: category,
        module: node_module,
        config: node_config,
        flow_id: flow_id
      }
    end
      
  end
  
  def get_all_connections do
    query_stm = "select id, source_id, target_id, flow_id from connections;"
    {:ok, result} = DbProxy.query query_stm, []

    # convert result from db to node struct
    Enum.map result.rows, fn([id, source_id, target_id, flow_id]) ->

      conn_id   = id |> UUID.binary_to_string! |> String.to_atom
      source_id = source_id |> UUID.binary_to_string! |> String.to_atom
      target_id = target_id |> UUID.binary_to_string! |> String.to_atom
      flow_id   = flow_id |> UUID.binary_to_string! |> String.to_atom
      
      %Connection{
        id: conn_id,
        source_id: source_id,
        target_id: target_id,
        flow_id: flow_id
      }
    end    
  end

  def start_nodes do
    nodes = get_all_nodes()
    Enum.each nodes, fn(node) ->
      instance = node.module.create_instance(node.id, node.config)
      IO.inspect instance, label: node.name
    end
  end

end