"""Inference must refuse to guess a CRS.

Detection QA rejects a tile without explicit CRS metadata, but the inference
side silently assumed EPSG:4326. That produced geometry that renders as a
plausible polygon in the wrong place, which is worse than a clear failure:
"fail closed" is the stated rule for the runtime.
"""

from __future__ import annotations

import pytest

from app.core.errors import AppError
from app.services.detection_georeferencing import (
    pixel_bbox_to_epsg4326_polygon,
    pixel_points_to_epsg4326_polygon,
)
from app.services.detection_service import DetectionService


TILE_WITHOUT_CRS = {
    "bounds": [4.0, 51.0, 5.0, 52.0],
    "pixel_window": [0, 0, 100, 100],
}


def test_manifest_without_crs_is_rejected() -> None:
    with pytest.raises(AppError) as exc_info:
        DetectionService._require_manifest_crs({"tiles": [{"bounds": [0, 0, 1, 1]}]})

    assert exc_info.value.code == "DETECTION_TILE_MANIFEST_INVALID"


def test_manifest_crs_is_read_from_any_of_the_documented_keys() -> None:
    assert DetectionService._require_manifest_crs({"crs": "EPSG:31370"}) == "EPSG:31370"
    assert DetectionService._require_manifest_crs({"source_crs": "EPSG:31370"}) == "EPSG:31370"
    assert DetectionService._require_manifest_crs({"dataset_crs": "EPSG:3812"}) == "EPSG:3812"


def test_bbox_georeferencing_requires_an_explicit_crs() -> None:
    with pytest.raises(AppError) as exc_info:
        pixel_bbox_to_epsg4326_polygon(bbox=[0.0, 0.0, 10.0, 10.0], tile=TILE_WITHOUT_CRS)

    assert exc_info.value.code == "DETECTION_TILE_CRS_REQUIRED"


def test_mask_georeferencing_requires_an_explicit_crs() -> None:
    with pytest.raises(AppError) as exc_info:
        pixel_points_to_epsg4326_polygon(
            points=[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0]], tile=TILE_WITHOUT_CRS
        )

    assert exc_info.value.code == "DETECTION_TILE_CRS_REQUIRED"


def test_explicit_crs_on_the_tile_is_used() -> None:
    tile = {**TILE_WITHOUT_CRS, "crs": "EPSG:4326"}

    polygon = pixel_bbox_to_epsg4326_polygon(bbox=[0.0, 0.0, 50.0, 50.0], tile=tile)

    assert polygon.bounds == pytest.approx((4.0, 51.5, 4.5, 52.0))


def test_projected_bounds_are_reprojected_as_a_whole_rectangle() -> None:
    # Lambert 72 around Mol. All four corners must be transformed, otherwise a
    # rotated footprint is understated.
    bounds = DetectionService._bounds_to_epsg4326([200000.0, 200000.0, 201000.0, 201000.0], "EPSG:31370")

    assert bounds is not None
    min_x, min_y, max_x, max_y = bounds
    assert 4.0 < min_x < 6.0
    assert 50.0 < min_y < 52.0
    assert max_x > min_x and max_y > min_y