require_relative "test_helper"
require "maptool/fit"

class FitTest < Minitest::Test
  def le32(n)
    [n].pack("l<")
  end

  # A minimal hand-built FIT file: header + one definition message (local
  # type 0, global mesg 20 "record", fields position_lat/position_long,
  # both sint32) + data messages. Exercises the header/definition/data
  # framing without needing an external fixture file.
  def build_fit(records)
    definition = [0, 0].pack("CC") + [20].pack("S<") + [2].pack("C") +
                 [0, 4, 0x85].pack("C3") + [1, 4, 0x85].pack("C3")
    definition_header = [0b01000000].pack("C")

    data = records.map { |lat, lon| [0b00000000].pack("C") + le32(lat) + le32(lon) }.join

    body = definition_header + definition + data
    header = [12, 16, 0, 0].pack("C2S<") + le32(body.bytesize) + ".FIT"
    header + body + "\x00\x00"
  end

  def write_fit(records)
    path = File.join(Dir.mktmpdir, "test.fit")
    File.binwrite(path, build_fit(records))
    path
  end

  def test_parses_coordinates_from_record_messages
    path = write_fit([[100_000_000, 200_000_000], [100_000_100, 200_000_100]])

    geojson = Maptool::Fit.to_geojson(path)
    coords = geojson["features"][0]["geometry"]["coordinates"][0]

    assert_equal 2, coords.size
    expected_lat = 100_000_000 * Maptool::Fit::SEMICIRCLE_TO_DEGREES
    expected_lon = 200_000_000 * Maptool::Fit::SEMICIRCLE_TO_DEGREES
    assert_in_delta expected_lat, coords[0][1], 1e-9
    assert_in_delta expected_lon, coords[0][0], 1e-9
  end

  def test_kinds_is_track_when_positioned
    assert_equal ["track"], Maptool::Fit.kinds(write_fit([[100_000_000, 200_000_000]]))
  end

  def test_a_file_with_no_positioned_records_has_no_features_or_kinds
    path = write_fit([])
    assert_empty Maptool::Fit.to_geojson(path)["features"]
    assert_empty Maptool::Fit.kinds(path)
  end

  def test_garbage_input_raises_parse_error
    path = File.join(Dir.mktmpdir, "garbage.fit")
    File.binwrite(path, "not a fit file at all")

    assert_raises(Maptool::Fit::ParseError) { Maptool::Fit.to_geojson(path) }
  end
end