defmodule Mix.Tasks.Analytics3i.Count do
  use Mix.Task

  require Logger

  @shortdoc "Count"

  def run(_) do
    {:ok, _} = Application.ensure_all_started(:analytics_3i)

    Logger.add_backend {LoggerFileBackend, :debug}

    Logger.configure_backend {LoggerFileBackend, :debug},
                             path: Path.expand("../../../log/debug.log", __DIR__),
                             format: "$time $metadata[$level] $message\n"

    otrasl_list = load_yaml("data/otrasl.yml")
    st_list = load_yaml("data/st.yml")

    result =
      Path.wildcard("output/*.csv")
      |> Enum.reduce(%{dataProvider: %{}}, fn (file_name, acc) ->
        {otrasl, st} = otrasl_st(file_name)

        count = File.stream!(file_name)
                |> Stream.with_index
                |> Enum.count()

        otrasl_data = Map.get(acc[:dataProvider], otrasl, %{name: otrasl_list[otrasl]["name"], data: %{}})
        otrasl_data = Map.put(otrasl_data, :data, Map.put(otrasl_data[:data], st, count - 1))

        Map.put(acc, :dataProvider, Map.put(acc[:dataProvider], otrasl, otrasl_data))
      end)

    dataValues =
      result[:dataProvider]
      |> Enum.map(fn {_, value} ->
        result =
          value[:data]
          |> Enum.reduce(%{}, fn ({k, v}, acc) ->
            Map.put(acc, st_list[k]["name"], v)
          end)
        total =
          result
          |> Enum.reduce(0, fn {_, v}, acc -> acc + v end)
        result
          |> Map.put(:Label, value[:name])
          |> Map.put(:Total, total)

      end)

    write_csv!(Map.keys(List.first(dataValues)), dataValues)
  end

  defp otrasl_st(file_name) do
    info = String.split(Path.basename(file_name), ~r{[_.]})

    otrasl_name_size = Enum.count(info) - 3
    otrasl_name_size = if Enum.at(info, otrasl_name_size) == "new", do: otrasl_name_size - 1, else: otrasl_name_size
    otrasl_name = (1..otrasl_name_size) |> Enum.map(fn x -> Enum.at(info, x) end) |> Enum.join("_")

    st_name_size = Enum.count(info) - otrasl_name_size - 2
    st_name = (otrasl_name_size + 1..otrasl_name_size + st_name_size) |> Enum.map(fn x -> Enum.at(info, x) end) |> Enum.join("_")

    {otrasl_name, st_name}
  end

  defp load_yaml(path) do
    path = File.cwd! |> Path.join(path)
    {:ok, data} = YamlElixir.read_from_file path

    data
  end

  defp write_csv!(keys, values) do
    File.open("data/graph_dots_total.csv", [:write, :utf8], fn(file) ->
      values
      |> CSV.encode(headers: keys)
      |> Enum.each(&IO.write(file, &1))
    end)
  end
end