from __future__ import annotations

from io import BytesIO

import httpx
import pytest
from PIL import Image

from beefy_player import artwork


def png_bytes(size=(400, 200), alpha: int = 180) -> bytes:
    buffer = BytesIO()
    Image.new("RGBA", size, (20, 180, 220, alpha)).save(buffer, format="PNG")
    return buffer.getvalue()


def ink_bbox(image: Image.Image):
    """Where the artwork itself is, ignoring transparent or black padding."""
    return image.convert("RGB").getbbox()


def opaque_png_bytes(size=(400, 200)) -> bytes:
    buffer = BytesIO()
    Image.new("RGB", size, (20, 180, 220)).save(buffer, format="PNG")
    return buffer.getvalue()


def test_protocol_detection() -> None:
    assert artwork.detect_protocol({"KITTY_WINDOW_ID": "1"}) == "tgp"
    assert artwork.detect_protocol({"TERM": "xterm-kitty"}) == "tgp"
    assert artwork.detect_protocol({"TERM_PROGRAM": "WezTerm"}) == "iterm2"
    assert artwork.detect_protocol({"WEZTERM_EXECUTABLE": "/bin/wezterm"}) == "iterm2"
    assert artwork.detect_protocol({"TERM_PROGRAM": "iTerm.app"}) == "iterm2"
    assert artwork.detect_protocol({"ITERM_SESSION_ID": "x"}) == "iterm2"
    assert artwork.detect_protocol({"TERM_PROGRAM": "Apple_Terminal"}) is None
    assert artwork.detect_protocol({"TMUX": "/tmp/tmux", "KITTY_WINDOW_ID": "1"}) == "tgp"
    assert artwork.detect_protocol({"TMUX": "/tmp/tmux", "TERM_PROGRAM": "WezTerm"}) is None
    assert artwork.detect_protocol({"ZELLIJ": "1", "TERM_PROGRAM": "WezTerm"}) is None
    assert artwork.detect_protocol({"KITTY_PID": "1"}) == "tgp"
    assert artwork.detect_protocol({"NO_COLOR": "", "KITTY_WINDOW_ID": "1"}) is None
    assert artwork.detect_protocol({"BEEFY_IMAGES": "0", "KITTY_WINDOW_ID": "1"}) is None
    assert artwork.detect_protocol({"BEEFY_IMAGES": "tgp"}) == "tgp"
    assert artwork.detect_protocol({"BEEFY_IMAGES": "iterm2"}) == "iterm2"
    # the pre-rename variable still works
    assert artwork.detect_protocol({"SOMAFM_IMAGES": "0"}) is None


def test_fit_image_letterboxes_inside_the_cell_box() -> None:
    fitted = artwork.fit_image(png_bytes((400, 200)), 13, 8)
    assert fitted is not None
    cell_width, cell_height = artwork.cell_size()
    assert (fitted.width, fitted.height) == (13 * cell_width, 8 * cell_height)

    # the ink keeps its own 2:1 aspect instead of being cropped to the box
    ink = ink_bbox(fitted)
    assert ink is not None
    left, top, right, bottom = ink
    assert (right - left) / (bottom - top) == pytest.approx(2.0, rel=0.02)
    # a wide image is padded above and below, and spans the full width
    assert left == 0 and right == fitted.width
    assert top > 0 and bottom < fitted.height


def test_an_image_with_alpha_gets_a_black_backing() -> None:
    """Transparent artwork is drawn over the mosaic; black keeps it readable."""
    fitted = artwork.fit_image(png_bytes((400, 200)), 13, 8)
    assert fitted is not None
    # every pixel is opaque now, and the padding is black rather than mosaic
    assert fitted.getchannel("A").getextrema() == (255, 255)
    assert fitted.getpixel((0, 0)) == (0, 0, 0, 255)
    # the ink is still letterboxed, not cropped: its own 2:1 aspect survives
    ink = ink_bbox(fitted)
    assert ink is not None
    left, top, right, bottom = ink
    assert (right - left) / (bottom - top) == pytest.approx(2.0, rel=0.02)


def test_an_opaque_image_keeps_the_transparent_padding() -> None:
    """No alpha channel: nothing to hide, so the mosaic shows through."""
    fitted = artwork.fit_image(opaque_png_bytes((400, 200)), 13, 8)
    assert fitted is not None
    assert fitted.getpixel((0, 0))[3] == 0
    ink = ink_bbox(fitted)
    assert ink is not None
    left, top, right, bottom = ink
    assert (right - left) / (bottom - top) == pytest.approx(2.0, rel=0.02)


def test_fit_image_centres_a_tall_image() -> None:
    fitted = artwork.fit_image(png_bytes((100, 400)), 13, 8)
    assert fitted is not None
    ink = ink_bbox(fitted)
    assert ink is not None
    left, _, right, _ = ink
    assert left > 0 and right < fitted.width
    assert right - left == pytest.approx(fitted.height / 4, rel=0.05)


def test_fit_image_rejects_garbage() -> None:
    assert artwork.fit_image(b"not an image", 13, 8) is None


def test_image_cache_roundtrip() -> None:
    data = png_bytes()
    url = "https://example.invalid/art.png"
    artwork.save_cached(url, data)
    assert artwork.load_cached(url) == data
    assert artwork.load_cached("https://example.invalid/other.png") is None


@pytest.mark.asyncio
async def test_fetch_validates_and_caches() -> None:
    data = png_bytes((120, 120))
    url = "https://example.invalid/logo.png"

    def handler(request: httpx.Request) -> httpx.Response:
        return httpx.Response(200, content=data, headers={"content-type": "image/png"})

    async with httpx.AsyncClient(transport=httpx.MockTransport(handler)) as client:
        fetched = await artwork.fetch(client, url)
    assert fetched == data
    assert artwork.load_cached(url) == data


def test_multiplexer_env_values_that_mean_no() -> None:
    # Some wrappers export ZELLIJ=0 / TMUX=0 outside a multiplexer; that must
    # not disable iTerm2 or Kitty graphics.
    assert artwork.detect_protocol({"ZELLIJ": "0", "TERM_PROGRAM": "iTerm.app"}) == "iterm2"
    assert artwork.detect_protocol({"ZELLIJ": "", "TERM_PROGRAM": "iTerm.app"}) == "iterm2"
    assert artwork.detect_protocol({"TMUX": "0", "KITTY_WINDOW_ID": "1"}) == "tgp"
    # ...while a real multiplexer still downgrades to the mosaic.
    assert artwork.detect_protocol({"TMUX": "/tmp/tmux-501/default,1,0", "TERM_PROGRAM": "iTerm.app"}) is None
    assert artwork.detect_protocol({"STY": "1234.pts-0.host", "TERM_PROGRAM": "iTerm.app"}) is None