"""Unit tests for POST /palette/extract."""

from __future__ import annotations

import base64
import io

import pytest
from PIL import Image

from svrnty_vision.routers.palette import PaletteRequest, PaletteResponse, extract


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _make_png_b64(color: tuple[int, int, int], size: int = 50) -> str:
    img = Image.new("RGB", (size, size), color=color)
    buf = io.BytesIO()
    img.save(buf, format="PNG")
    return base64.b64encode(buf.getvalue()).decode("ascii")


# ---------------------------------------------------------------------------
# Unit tests (pure function / TestClient — no network)
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_solid_red_dominant_is_red() -> None:
    req = PaletteRequest(image_base64=_make_png_b64((255, 0, 0)), color_count=3)
    resp: PaletteResponse = await extract(req)
    r, g, b = resp.dominant
    assert r > 200, "dominant R channel should be high for solid red"
    assert g < 80
    assert b < 80


@pytest.mark.asyncio
async def test_palette_color_count_respected() -> None:
    req = PaletteRequest(image_base64=_make_png_b64((0, 128, 255)), color_count=4)
    resp = await extract(req)
    assert resp.color_count <= 4
    assert len(resp.palette) == resp.color_count


@pytest.mark.asyncio
async def test_palette_each_entry_is_rgb_triple() -> None:
    req = PaletteRequest(image_base64=_make_png_b64((100, 200, 50)), color_count=6)
    resp = await extract(req)
    for entry in resp.palette:
        assert len(entry) == 3
        assert all(0 <= c <= 255 for c in entry)


@pytest.mark.asyncio
async def test_palette_missing_image_raises_400() -> None:
    from fastapi import HTTPException
    with pytest.raises(HTTPException) as exc_info:
        await extract(PaletteRequest())
    assert exc_info.value.status_code == 400


@pytest.mark.asyncio
async def test_palette_bad_base64_raises_400() -> None:
    from fastapi import HTTPException
    with pytest.raises(HTTPException) as exc_info:
        await extract(PaletteRequest(image_base64="!!!notbase64!!!"))
    assert exc_info.value.status_code == 400


def test_palette_via_test_client(client, red_png_b64) -> None:
    resp = client.post("/palette/extract", json={"image_base64": red_png_b64, "color_count": 5})
    assert resp.status_code == 200
    body = resp.json()
    assert "dominant" in body
    assert len(body["dominant"]) == 3
    assert body["color_count"] <= 5
    assert len(body["palette"]) == body["color_count"]