import hashlib
import json
from pathlib import Path

from PIL import Image

import overview
from leonida.coords import SLICE


def _ring(x0, z0, x1, z1):
    return [[x0, z0], [x1, z0], [x1, z1], [x0, z1], [x0, z0]]


def _fixture(tmp_path: Path) -> Path:
    """Ein einziger Chunk A1 (Nordwest): Land, eine Straße, ein Gebäude, eine Palme.

    Chunk-lokale Koordinaten von chunk_0_0 fallen bei scale 1 genau auf die Kartenpixel,
    weil der Chunk-Ursprung die Nordwest-Ecke des Ausschnitts ist.
    """
    chunk = {
        "chunk": [0, 0],
        "origin": [SLICE["x0"], -SLICE["y1"]],
        "land": [[_ring(0, 0, 250, 250)]],
        "surfaces": [],
        "roads": [{"poly": [_ring(100, 0, 120, 250)], "bridge": False}],
        "centerlines": [],
        "buildings": [{"poly": [_ring(20, 20, 60, 60)], "height": 12.0, "source": "district", "speculative": False}],
        "palms": [[200.0, 200.0]],
    }
    (tmp_path / "chunk_0_0.json").write_text(json.dumps(chunk))
    (tmp_path / "manifest.json").write_text('{"slice": "vice-a"}\n')
    return tmp_path


def test_map_picture_has_one_pixel_per_metre_and_no_palms(tmp_path):
    src = tmp_path / "chunks"
    src.mkdir()
    _fixture(src)
    dst = tmp_path / "out"
    overview.render_map(src, dst)
    picture = Image.open(dst / "map.png")
    assert picture.size == (3000, 3000)
    assert picture.getpixel((110, 125)) == overview.ROAD
    assert picture.getpixel((40, 40)) == overview._building_shade(12.0)
    assert picture.getpixel((200, 200)) == overview.LAND      # Palme wird nicht gezeichnet
    assert picture.getpixel((1500, 1500)) == overview.WATER


def test_walkable_mask_blocks_buildings_and_water(tmp_path):
    src = tmp_path / "chunks"
    src.mkdir()
    _fixture(src)
    dst = tmp_path / "out"
    overview.render_map(src, dst)
    mask = Image.open(dst / "map-walkable.png")
    assert mask.mode == "L"
    assert mask.size == (750, 750)
    assert mask.getpixel((10, 10)) == overview.BLOCKED       # Gebäude bei 40 m / 40 m
    assert mask.getpixel((27, 31)) == overview.WALKABLE      # Straße bei 110 m / 125 m
    assert mask.getpixel((50, 50)) == overview.WALKABLE      # Land bei 200 m / 200 m
    assert mask.getpixel((375, 375)) == overview.BLOCKED     # Wasser


def test_map_json_carries_scale_slice_and_manifest_fingerprint(tmp_path):
    src = tmp_path / "chunks"
    src.mkdir()
    _fixture(src)
    dst = tmp_path / "out"
    overview.render_map(src, dst)
    info = json.loads((dst / "map.json").read_text())
    assert info["scale"] == 1.0
    assert info["walkable_scale"] == 0.25
    assert info["slice"] == SLICE
    assert info["manifest_sha256"] == hashlib.sha256((src / "manifest.json").read_bytes()).hexdigest()


def test_debug_overview_still_draws_palms(tmp_path):
    src = tmp_path / "chunks"
    src.mkdir()
    _fixture(src)
    dst = tmp_path / "debug.png"
    stats = overview.render(src, dst)
    assert stats["palmen"] == 1
    assert Image.open(dst).getpixel((100, 100)) == overview.PALM   # 200 m bei 0,5 px/m