defmodule Microwaveprop.DataCase do
  @moduledoc """
  This module defines the setup for tests requiring
  access to the application's data layer.

  You may define functions here to be used as helpers in
  your tests.

  Finally, if the test case interacts with the database,
  we enable the SQL sandbox, so changes done to the database
  are reverted at the end of every test. If you are using
  PostgreSQL, you can even run database tests asynchronously
  by setting `use Microwaveprop.DataCase, async: true`, although
  this option is not recommended for other databases.
  """

  use ExUnit.CaseTemplate

  alias Ecto.Adapters.SQL.Sandbox

  using do
    quote do
      import Ecto
      import Ecto.Changeset
      import Ecto.Query
      import Microwaveprop.DataCase

      alias Microwaveprop.Repo
    end
  end

  setup tags do
    Microwaveprop.DataCase.setup_sandbox(tags)
    Microwaveprop.DataCase.reset_score_files()
    Microwaveprop.DataCase.stub_nexrad_default()
    :ok
  end

  @doc """
  Installs a default 404 stub for the IEM NEXRAD client so tests that
  trigger `CommonVolumeRadarWorker` via `enqueue_for_contact/1` don't
  crash for lack of a Req.Test plug. Individual tests can override with
  their own `Req.Test.stub/2`.
  """
  def stub_nexrad_default do
    Req.Test.stub(Microwaveprop.Weather.NexradClient, fn conn ->
      Plug.Conn.send_resp(conn, 404, "not found")
    end)
  end

  @doc """
  Sets up the sandbox based on the test tags.
  """
  def setup_sandbox(tags) do
    pid = Sandbox.start_owner!(Microwaveprop.Repo, shared: not tags[:async])
    on_exit(fn -> Sandbox.stop_owner(pid) end)
  end

  @doc """
  Wipe the propagation ScoresFile tree between tests so files don't
  leak between cases sharing the same tmp dir.
  """
  def reset_score_files do
    dir = Application.get_env(:microwaveprop, :propagation_scores_dir)
    if is_binary(dir), do: File.rm_rf!(dir)
  end

  @doc """
  A helper that transforms changeset errors into a map of messages.

      assert {:error, changeset} = Accounts.create_user(%{password: "short"})
      assert "password is too short" in errors_on(changeset).password
      assert %{password: ["password is too short"]} = errors_on(changeset)

  """
  def errors_on(changeset) do
    Ecto.Changeset.traverse_errors(changeset, fn {message, opts} ->
      Regex.replace(~r"%{(\w+)}", message, fn _, key ->
        opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
      end)
    end)
  end
end
