"""The BBS frames: grey edges, and a short palette glow in two corners."""

from __future__ import annotations

from rich.text import Text

from beefy_player.palettes import PALETTES, brightness
from beefy_player.widgets import frame

#: The original ladder, used as a fixed reference in these tests.
STOPS = PALETTES["spectrum"]
#: Its glow: the brightest cell first, dimmer cells towards the edge.
RAMP = frame.fade_ramp(STOPS)
HOT = RAMP[0]  # the corner colour


def styles_of(line: Text) -> list[tuple[str, str]]:
    return [
        (line.plain[span.start : span.end], str(span.style)) for span in line.spans
    ]


def test_the_corner_gets_the_brightest_colour_of_the_fade() -> None:
    ranks = [brightness(colour) for colour in RAMP]
    assert ranks == sorted(ranks, reverse=True)
    # spectrum's hot end is red, which is dimmer than the yellow before it:
    # the corner must still be the bright one, not the ladder's last stop
    assert STOPS[-1] != HOT
    assert brightness(HOT) > brightness(STOPS[-1])
    assert set(RAMP) <= set(STOPS)
    assert frame.corner_fade(len(RAMP), STOPS) == frame.EDGE


def test_only_the_top_right_corner_fades_on_the_top_edge() -> None:
    spans = styles_of(frame.top(30, stops=STOPS))
    assert spans[0] == ("╭", frame.EDGE)  # plain grey corner
    # the fade runs into the top-right corner, brightest cell last
    assert [style for _text, style in spans[-4:-1]] == [RAMP[3], RAMP[2], RAMP[1]]
    assert spans[-1] == ("╮", f"bold {HOT}")


def test_only_the_bottom_left_corner_fades_on_the_bottom_edge() -> None:
    spans = styles_of(frame.bottom(30, STOPS))
    assert spans[0] == ("╰", f"bold {HOT}")
    assert [style for _text, style in spans[1:4]] == [RAMP[1], RAMP[2], RAMP[3]]
    assert spans[-1] == ("╯", frame.EDGE)  # plain grey corner


def test_the_sides_glow_towards_their_own_corner_only() -> None:
    # left column fades up from the bottom-left corner
    assert [frame.side_style(row, 10, "left", STOPS) for row in range(10)] == [
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        RAMP[3],
        RAMP[2],
        RAMP[1],
    ]
    # right column fades down from the top-right corner
    assert [frame.side_style(row, 10, "right", STOPS) for row in range(10)] == [
        RAMP[1],
        RAMP[2],
        RAMP[3],
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
        frame.EDGE,
    ]


def test_the_title_sits_after_the_left_fade() -> None:
    line = frame.top(30, "STATIONS", STOPS)
    assert line.plain.startswith("╭─ STATIONS ─")
    assert "STATIONS" in line.plain
    # a pane too narrow for the title drops it rather than truncating
    assert "STATIONS" not in frame.top(10, "STATIONS", STOPS).plain


def test_wrap_frames_the_content_on_every_row() -> None:
    content = [Text("hello"), Text("world")]
    group = frame.wrap(content, 20, 6, "PANE", STOPS)
    lines = [line.plain for line in group.renderables]
    assert len(lines) == 6
    assert lines[0].startswith("╭") and lines[-1].startswith("╰")
    assert all(len(line) == 20 for line in lines)
    assert all(line.startswith("│") and line.endswith("│") for line in lines[1:-1])
    assert lines[1].startswith("│hello")


def test_content_wider_than_the_pane_is_trimmed_not_spilled() -> None:
    """A pane must never draw over its neighbour."""
    long_line = Text("x" * 40)
    group = frame.wrap([long_line], 20, 4, "PANE", STOPS)
    lines = [line.plain for line in group.renderables]
    assert all(len(line) == 20 for line in lines)
    assert lines[1].endswith("│")
    # the original renderable is left untouched
    assert long_line.plain == "x" * 40


def test_a_short_pane_still_glows_in_its_bottom_left_corner() -> None:
    """The fade follows the pane's height, not the number of content rows."""
    group = frame.wrap([Text("one line")], 20, 6, stops=STOPS)
    lines = list(group.renderables)
    # rows 1-4 are the content box; the fade climbs its last three rows
    assert str(lines[1].spans[0].style) == frame.EDGE
    assert [str(line.spans[0].style) for line in lines[2:5]] == [
        RAMP[3],
        RAMP[2],
        RAMP[1],
    ]