"""The BBS frames: grey edges, corners fading white → grey → cyan."""

from __future__ import annotations

from rich.text import Text

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

#: The original ladder, used as a fixed reference in these tests.
STOPS = PALETTES["spectrum"]
HOT = STOPS[-1]  # 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_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, hot end last
    assert [style for _text, style in spans[-4:-1]] == [
        STOPS[-4],
        STOPS[-3],
        STOPS[-2],
    ]
    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]] == [
        STOPS[-2],
        STOPS[-3],
        STOPS[-4],
    ]
    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,
        STOPS[-4],
        STOPS[-3],
        STOPS[-2],
    ]
    # right column fades down from the top-right corner
    assert [frame.side_style(row, 10, "right", STOPS) for row in range(10)] == [
        STOPS[-2],
        STOPS[-3],
        STOPS[-4],
        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