defmodule Microwaveprop.Buildings.BulkFetchTest do
  use ExUnit.Case, async: false

  import ExUnit.CaptureLog

  alias Microwaveprop.Buildings.BulkFetch

  doctest BulkFetch

  setup do
    tmp_dir =
      Path.join(System.tmp_dir!(), "bulk_fetch_test_#{System.unique_integer([:positive])}")

    File.mkdir_p!(tmp_dir)

    prev_cache_dir = Application.get_env(:microwaveprop, :buildings_cache_dir)
    prev_http_get = Application.get_env(:microwaveprop, :ms_footprints_http_get)

    Application.put_env(:microwaveprop, :buildings_cache_dir, tmp_dir)

    Application.put_env(:microwaveprop, :ms_footprints_http_get, fn _url, _opts ->
      {:ok, %{status: 200, body: "Location\tQuadkey\tUrl\tSize\n"}}
    end)

    Microwaveprop.Cache.invalidate(:ms_footprints_index)

    on_exit(fn ->
      File.rm_rf!(tmp_dir)

      if prev_cache_dir,
        do: Application.put_env(:microwaveprop, :buildings_cache_dir, prev_cache_dir),
        else: Application.delete_env(:microwaveprop, :buildings_cache_dir)

      if prev_http_get,
        do: Application.put_env(:microwaveprop, :ms_footprints_http_get, prev_http_get),
        else: Application.delete_env(:microwaveprop, :ms_footprints_http_get)
    end)

    %{tmp_dir: tmp_dir}
  end

  describe "run/4" do
    test "returns the result struct with zero counters when index is empty" do
      # Stub the dataset index fetch to return empty TSV -> no quadkeys
      # in index -> no downloads attempted.
      Application.put_env(:microwaveprop, :ms_footprints_http_get, fn _url, _opts ->
        {:ok, %{status: 200, body: "Location\tQuadkey\tUrl\tSize\n"}}
      end)

      # Need to invalidate the dataset_index cache so our stub takes effect.
      Microwaveprop.Cache.invalidate(:ms_footprints_index)

      capture_log(fn ->
        result = BulkFetch.run(32.8, -97.0, 1, concurrency: 1)
        send(self(), result)
      end)

      assert_received %{
        downloaded: 0,
        cached: 0,
        failed: 0,
        missing: missing,
        cache_dir: cache_dir
      }

      assert is_integer(missing)
      assert byte_size(cache_dir) > 0
    end
  end
end