from __future__ import annotations

from pathlib import Path

from PIL import Image

from tmux_shot.render import frames_to_gif, render_ansi_to_png


def test_render_plain_text_produces_correctly_sized_image(out_dir: Path) -> None:
    path = render_ansi_to_png("hello world", out_dir / "plain.png", cols=20, rows=3, font_size=14)
    img = Image.open(path)
    assert img.size[0] > 0 and img.size[1] > 0
    # 20 cols x 3 rows of cells, image should be a whole multiple of cell size in each axis
    assert img.width % 20 == 0
    assert img.height % 3 == 0


def test_render_resolves_truecolor_background_and_foreground(out_dir: Path) -> None:
    # SGR 38;2 = truecolor fg, 48;2 = truecolor bg. Pure red bg, pure green text.
    ansi = "\x1b[48;2;255;0;0m\x1b[38;2;0;255;0mX\x1b[0m"
    path = render_ansi_to_png(ansi, out_dir / "color.png", cols=1, rows=1, font_size=20)
    img = Image.open(path)
    # corner pixel is background-only (no glyph ink there)
    corner = img.getpixel((0, 0))
    assert corner == (255, 0, 0)


def test_render_reverse_video_swaps_fg_and_bg(out_dir: Path) -> None:
    ansi = "\x1b[38;2;255;0;0m\x1b[48;2;0;0;255m\x1b[7mX\x1b[0m"  # red fg, blue bg, reversed
    path = render_ansi_to_png(ansi, out_dir / "reverse.png", cols=1, rows=1, font_size=20)
    img = Image.open(path)
    # reversed: background should now be the (originally-foreground) red
    assert img.getpixel((0, 0)) == (255, 0, 0)


def test_render_handles_ansi_16_color_names(out_dir: Path) -> None:
    ansi = "\x1b[42mX\x1b[0m"  # classic SGR green background
    path = render_ansi_to_png(ansi, out_dir / "named.png", cols=1, rows=1, font_size=20)
    img = Image.open(path)
    assert img.getpixel((0, 0)) == (0, 205, 0)


def test_frames_to_gif_stitches_multiple_pngs_into_one_animation(out_dir: Path) -> None:
    frame_paths = []
    for i, label in enumerate(["one", "two", "three"]):
        p = render_ansi_to_png(f"frame {label}", out_dir / f"f{i}.png", cols=10, rows=1, font_size=14)
        frame_paths.append(p)

    gif_path = frames_to_gif(frame_paths, out_dir / "movie.gif", duration_ms=100)
    assert Path(gif_path).exists()

    with Image.open(gif_path) as gif:
        assert gif.is_animated
        assert gif.n_frames == 3


def test_frames_to_gif_rejects_empty_input(out_dir: Path) -> None:
    import pytest

    with pytest.raises(ValueError):
        frames_to_gif([], out_dir / "empty.gif")