"""The braille renderer, which is the one part of the dashboard that is logic.

The screens around it are wiring the type checker already covers; this is
arithmetic that a wrong sign would silently flip upside down.
"""

from fluksio.tui.chart import (
    DOTS,
    GUTTER,
    SERIES_STYLES,
    _cells,
    _place,
    legend,
    plot,
    shorten,
)


def test_a_diagonal_lands_in_the_corners_it_should() -> None:
    """Bottom left to top right, on a grid small enough to name every dot."""
    # Two cells across, one down: a 4x4 dot grid.
    cells, bounds = _cells([("a", [[0.0, 0.0], [1.0, 1.0]])], cols=2, rows=1)
    assert bounds == (0.0, 1.0, 0.0, 1.0)
    assert set(cells) == {(0, 0), (0, 1)}
    # The low reading sits at the bottom of the left cell...
    assert cells[0, 0][0] & DOTS[0][3]
    # ...and the high one at the top of the right, which is the y axis being
    # the right way up.
    assert cells[0, 1][0] & DOTS[1][0]
    assert cells[0, 0][1] == cells[0, 1][1] == 0


def test_readings_are_joined_rather_than_dotted() -> None:
    """Two readings far apart are a line, not two lonely dots."""
    cells, _ = _cells([("a", [[0.0, 0.0], [1.0, 1.0]])], cols=10, rows=4)
    assert len(cells) >= 9


def test_a_flat_curve_is_drawn_down_the_middle() -> None:
    """A metric that never moved has no range to divide by."""
    assert _place(5.0, 5.0, 5.0, 8) == 3
    drawn = plot([("a", [[0.0, 5.0], [1.0, 5.0], [2.0, 5.0]])], 40, 6)
    assert "5" in drawn.plain


def test_each_series_keeps_its_own_colour() -> None:
    drawn = plot(
        [("a", [[0.0, 0.0], [1.0, 0.0]]), ("b", [[0.0, 9.0], [1.0, 9.0]])], 40, 8
    )
    used = {span.style for span in drawn.spans}
    assert SERIES_STYLES[0] in used
    assert SERIES_STYLES[1] in used


def test_the_gutter_carries_the_real_bounds() -> None:
    drawn = plot([("a", [[0.0, 0.5], [10.0, 9.5]])], 60, 8, x_label="step")
    assert "9.5" in drawn.plain
    assert "0.5" in drawn.plain
    # And the x axis says what it is and where it ran.
    assert "step" in drawn.plain
    assert "10" in drawn.plain
    # Nothing wraps: a chart that reflowed would be unreadable.
    assert all(len(line) <= 60 for line in drawn.plain.splitlines())


def test_nothing_to_draw_says_so_instead_of_raising() -> None:
    assert "No readings" in plot([], 40, 8).plain
    assert "No readings" in plot([("a", [])], 40, 8).plain
    # One reading is a dot, not a division by zero.
    assert plot([("a", [[1.0, 2.0]])], 40, 8).plain.count("\n") == 7
    # And a pane with no room for a gutter says that rather than drawing junk.
    assert "Too small" in plot([("a", [[0.0, 1.0]])], GUTTER + 4, 3).plain


def test_a_run_is_named_by_the_tail_of_its_id() -> None:
    assert (
        shorten("0193ab7c-dead-beef-1234-aabbccddeeff (seed 3)") == "ccddeeff (seed 3)"
    )
    assert "■" in legend(["run-aaaaaaaa"]).plain