"""app.weather_render -- pure-logic drawing helpers, no HTTP/DB.
Mirrors calendar_render.py's own testing posture (this module has no
dedicated test file there either, since it's exercised indirectly via
test_widgets_calendar.py) but covers the non-obvious behavior worth
pinning down directly: build_multi_city's label shortening, and that
weather icons are filled with the panel's *exact* ink colors (not an
arbitrary bitmap's anti-aliased ones) -- the whole reason icons are
hand-drawn rather than a fetched/vendored image: an exact palette match
quantizes with zero dithering error to diffuse, where anything else
dithers into a visible speckle at these small on-panel sizes."""

from __future__ import annotations

from PIL import Image, ImageDraw

from app import weather_render
from app.image_pipeline import DEFAULT_PALETTE_RGB, _quantize


def test_build_multi_city_shortens_full_geocoder_labels_for_display(monkeypatch):
    """Cached entries carry the full disambiguated geocoder label (e.g.
    "Seattle, Washington, United States" -- see get_or_refresh_weather_
    widget_data/weather.geocode_city). Drawing the whole thing made a
    single city's row overflow past the widget's own width in practice
    (caught via browser verification) -- only the city name should reach
    draw_weather_row, same shortening calendar_render.py's
    _weather_for_day already does for its own embedded strip."""
    seen_labels = []
    real_draw_weather_row = weather_render.draw_weather_row

    def spy(img, draw, x0, y0, max_w, entries, icon_r, font, units, show_labels=True, palette_rgb=None):
        seen_labels.extend(e["label"] for e in entries)
        return real_draw_weather_row(img, draw, x0, y0, max_w, entries, icon_r, font, units, show_labels,
                                     palette_rgb)

    monkeypatch.setattr(weather_render, "draw_weather_row", spy)

    cities = [
        {"label": "Seattle, Washington, United States", "high": 65, "low": 50, "category": "rain"},
        {"label": "Portland, Oregon, United States", "high": 75, "low": 55, "category": "clear"},
    ]
    img = weather_render.build_multi_city(cities, 400, 150)
    assert img.size == (400, 150)
    assert seen_labels == ["Seattle", "Portland"]


def test_build_multi_city_empty_list_returns_blank_canvas():
    img = weather_render.build_multi_city([], 400, 150)
    assert img.size == (400, 150)


def _colors_present(img: Image.Image) -> set[tuple[int, int, int]]:
    return {c for _, c in img.getcolors(maxcolors=100_000)}


def test_draw_weather_icon_clear_uses_exact_panel_yellow():
    img = Image.new("RGB", (100, 100), (255, 255, 255))
    draw = ImageDraw.Draw(img)
    weather_render.draw_weather_icon(draw, 50, 50, 30, "clear")
    assert tuple(DEFAULT_PALETTE_RGB[2]) in _colors_present(img)  # yellow sun
    assert (0, 0, 0) not in _colors_present(img)  # not a flat-black glyph


def test_draw_weather_icon_rain_uses_exact_panel_blue():
    img = Image.new("RGB", (100, 100), (255, 255, 255))
    draw = ImageDraw.Draw(img)
    weather_render.draw_weather_icon(draw, 50, 50, 30, "rain")
    assert tuple(DEFAULT_PALETTE_RGB[4]) in _colors_present(img)  # blue raindrops


def test_draw_weather_icon_thunderstorm_uses_exact_panel_yellow():
    img = Image.new("RGB", (100, 100), (255, 255, 255))
    draw = ImageDraw.Draw(img)
    weather_render.draw_weather_icon(draw, 50, 50, 30, "thunderstorm")
    assert tuple(DEFAULT_PALETTE_RGB[2]) in _colors_present(img)  # yellow bolt


def test_draw_weather_icon_respects_a_custom_frame_palette():
    """A frame with an Advanced-configuration palette override (see
    Frame.palette_rgb) should still get ITS actual yellow, not the
    hardcoded default -- same resolution rule as calendar_render.py's
    _event_colors."""
    custom_palette = [(0, 0, 0), (255, 255, 255), (10, 20, 30), (0, 0, 0), (0, 0, 0), (0, 0, 0)]
    img = Image.new("RGB", (100, 100), (255, 255, 255))
    draw = ImageDraw.Draw(img)
    weather_render.draw_weather_icon(draw, 50, 50, 30, "clear", palette_rgb=custom_palette)
    assert (10, 20, 30) in _colors_present(img)


def test_icon_fill_quantizes_uniformly_with_no_dithering_speckle():
    """The actual point of hand-drawing icons in exact panel colors: a
    small crop taken from deep inside the sun disc (nowhere near its own
    edge) is a single flat fill -- if that fill weren't an exact palette
    match, _quantize's Floyd-Steinberg dithering would diffuse rounding
    error across it, breaking the crop into a speckle of 2+ colors. An
    exact match has zero error to diffuse, so the crop stays perfectly
    uniform after quantizing, same as before."""
    img = Image.new("RGB", (200, 200), (255, 255, 255))
    draw = ImageDraw.Draw(img)
    weather_render.draw_weather_icon(draw, 100, 100, 60, "clear")
    quantized = _quantize(img, DEFAULT_PALETTE_RGB, dither_strength=1.0).convert("RGB")

    # A 20x20 crop centered on the disc -- draw_sun's disc radius is
    # 0.55*60=33px, comfortably clear of both the outer edge and the ray
    # triangles' base line.
    crop = quantized.crop((90, 90, 110, 110))
    colors_in_crop = _colors_present(crop)
    assert colors_in_crop == {tuple(DEFAULT_PALETTE_RGB[2])}  # solid yellow, no speckle