defmodule Microwaveprop.Radio do
  @moduledoc false

  import Ecto.Query

  alias Microwaveprop.Radio.Qso
  alias Microwaveprop.Repo

  @per_page 20
  @sortable_fields ~w(station1 station2 band mode distance_km qso_timestamp)a

  def list_qsos(opts \\ []) do
    page = max(Keyword.get(opts, :page, 1), 1)
    offset = (page - 1) * @per_page

    {sort_field, sort_dir} = sort_opts(opts)

    total_entries = Repo.aggregate(Qso, :count)
    total_pages = max(ceil(total_entries / @per_page), 1)

    entries =
      Qso
      |> order_by([q], [{^sort_dir, field(q, ^sort_field)}])
      |> limit(^@per_page)
      |> offset(^offset)
      |> Repo.all()

    %{
      entries: entries,
      page: page,
      total_pages: total_pages,
      total_entries: total_entries
    }
  end

  defp sort_opts(opts) do
    sort_by = Keyword.get(opts, :sort_by, :qso_timestamp)
    sort_order = Keyword.get(opts, :sort_order, :desc)

    field = if sort_by in @sortable_fields, do: sort_by, else: :qso_timestamp
    dir = if sort_order in [:asc, :desc], do: sort_order, else: :desc

    {field, dir}
  end

  def get_qso!(id) do
    Repo.get!(Qso, id)
  end
end