defmodule ExCnab.Cnab240.Templates.Details.ModelN do
  @moduledoc """
  Template to generate an cnab 240 object from file, following the N-segment pattern;
  """
  import Helpers.ConvertPosition

  @doc """
  This function generate a Header Chunk Map from a Cnab240 file, using the **FEBRABAN** convention. The fields follows the O-segment hierarchy,
  and the returns is in PT BR.

  You can see all hierarchy in the FEBRABAN documentation.

  ```md
  CNAB
  ├── Controle
  │   ├── Banco (1..3)
  │   ├── Lote (4..7)
  │   └── Registro (8..8)
  │
  ├── Serviço
  │   ├── N do registro (9..13)
  │   ├── Segmento (14..14)
  │   └── Movimento
  │         ├── Tipo (15..15)
  │         └── Código (16..17)
  │
  ├── Pagamento
  │   ├── Seu numero (18..37)
  │   │
  │   ├── Nosso numero (38..57)
  │   │
  │   ├── Contribuinte (58..57)
  │   │
  │   ├── Data pagamento (88..95)
  │   │
  │   └── Valor pagamento (96..110)
  │
  ├── Informacoes complementares (111..230)
  │
  └── Ocorrências (231..240)
  """

  @spec generate(String.t()) :: {:ok, Map.t()}
  def generate(raw_string) do
    control_field = control_field(raw_string)
    service_field = service_field(raw_string)
    payment_field = payment_field(raw_string)

    complementary_info =
      raw_string
      |> convert_position(133, 134)
      |> complementary_info_fields(raw_string)

    {:ok,
     %{
       controle: control_field,
       servico: service_field,
       pagamento: payment_field,
       informacoes_complementares: complementary_info,
       ocorrencias: convert_position(raw_string, 231, 240)
     }}
  end

  defp control_field(raw_string) do
    %{
      banco: convert_position(raw_string, 1, 3),
      lote: convert_position(raw_string, 4, 7),
      registro: convert_position(raw_string, 8)
    }
  end

  defp service_field(raw_string) do
    %{
      n_registro: convert_position(raw_string, 9, 13),
      segmento: convert_position(raw_string, 14),
      movimento: %{
        tipo: convert_position(raw_string, 15),
        codigo: convert_position(raw_string, 16, 17)
      }
    }
  end

  defp payment_field(raw_string) do
    %{
      seu_numero: convert_position(raw_string, 18, 37),
      nosso_numero: convert_position(raw_string, 38, 57),
      contribuinte: convert_position(raw_string, 58, 87),
      data_pagamento: convert_position(raw_string, 88, 95),
      valor_pagamento: convert_position(raw_string, 96, 110)
    }
  end

  # DARF
  defp complementary_info_fields("16", raw_string) do
    %{
      receita: convert_position(raw_string, 111, 116),
      tipo_id_contribuinte: convert_position(raw_string, 117, 118),
      id_contribuinte: convert_position(raw_string, 119, 132),
      id_tributo: convert_position(raw_string, 133, 134),
      periodo: convert_position(raw_string, 135, 142),
      referencia: convert_position(raw_string, 143, 159),
      valor_principal: convert_position(raw_string, 158, 174),
      valor_multa: convert_position(raw_string, 175, 189),
      juros_e_encargos: convert_position(raw_string, 190, 204),
      data_vencimento: convert_position(raw_string, 205, 212),
      cnab: convert_position(raw_string, 213, 230)
    }
  end

  # GPS
  defp complementary_info_fields("17", raw_string) do
    %{
      receita: convert_position(raw_string, 111, 116),
      tipo_id_contribuinte: convert_position(raw_string, 117, 118),
      id_contribuinte: convert_position(raw_string, 119, 132),
      id_tributo: convert_position(raw_string, 133, 134),
      competencia: convert_position(raw_string, 135, 140),
      valor_tributo: convert_position(raw_string, 141, 155),
      valor_outras_entidades: convert_position(raw_string, 156, 170),
      atualizacao_monetaria: convert_position(raw_string, 171, 185),
      cnab: convert_position(raw_string, 186, 230)
    }
  end

  # DARF SIMPLES
  defp complementary_info_fields("18", raw_string) do
    %{
      receita: convert_position(raw_string, 111, 116),
      tipo_id_contribuinte: convert_position(raw_string, 117, 118),
      id_contribuinte: convert_position(raw_string, 119, 132),
      id_tributo: convert_position(raw_string, 133, 134),
      periodo: convert_position(raw_string, 135, 142),
      receita_bruta: convert_position(raw_string, 143, 157),
      percentual: convert_position(raw_string, 158, 164),
      valor_principal: convert_position(raw_string, 165, 179),
      valor_multa: convert_position(raw_string, 180, 194),
      juros_e_encargos: convert_position(raw_string, 195, 209),
      cnab: convert_position(raw_string, 210, 230)
    }
  end
end