"""Tests for rendering module (colormaps, tif_to_png)."""

import numpy as np
import rasterio
from rasterio.transform import from_bounds
import pytest
from pathlib import Path


def _make_test_tif(tmp_path, data=None, size=50):
    """Create a small test GeoTIFF and return its path."""
    if data is None:
        rng = np.random.default_rng(42)
        data = rng.normal(0, 1, (size, size)).astype(np.float32)

    transform = from_bounds(660000, 6700000, 661000, 6701000, size, size)
    tif_file = tmp_path / "test_vis.tif"
    with rasterio.open(
        tif_file, 'w', driver='GTiff', height=size, width=size,
        count=1, dtype='float32', crs='EPSG:2154', transform=transform,
        compress='lzw'
    ) as dst:
        dst.write(data, 1)
    return tif_file


class TestColormaps:
    def test_colormaps_dict_exists(self):
        from lidar_pipeline.rendering import COLORMAPS
        assert isinstance(COLORMAPS, dict)

    def test_all_viz_steps_have_colormaps(self):
        """Every VIZ_STEPS entry should have a corresponding COLORMAPS entry or render correctly."""
        from lidar_pipeline.pipeline import VIZ_STEPS
        from lidar_pipeline.rendering import COLORMAPS
        # Some viz names differ from colormap keys
        name_map = {
            'pos_open': 'positive_openness',
            'neg_open': 'negative_openness',
        }
        # IGN overlays (ortho, topo) are RGB images — no colormap needed
        skip = {'ortho', 'topo'}
        for name, _ in VIZ_STEPS:
            if name in skip:
                continue
            cmap_key = name_map.get(name, name)
            assert cmap_key in COLORMAPS, f"Missing colormap for: {name} (looked as {cmap_key})"

    def test_colormap_has_required_keys(self):
        """Each colormap entry must have cmap, title, legend, description."""
        from lidar_pipeline.rendering import COLORMAPS
        required = {'cmap', 'title', 'legend', 'description'}
        for name, entry in COLORMAPS.items():
            missing = required - set(entry.keys())
            assert not missing, f"Colormap '{name}' missing keys: {missing}"


class TestTifToPng:
    def test_converts_tif_to_webp(self, tmp_path):
        from lidar_pipeline.rendering import tif_to_png
        tif_file = _make_test_tif(tmp_path)
        result = tif_to_png(tif_file, tmp_path, 5.0)
        assert result is not None
        assert result.exists()
        assert result.suffix == '.webp'

    def test_removes_source_tif(self, tmp_path):
        from lidar_pipeline.rendering import tif_to_png
        tif_file = _make_test_tif(tmp_path)
        assert tif_file.exists()
        tif_to_png(tif_file, tmp_path, 5.0)
        assert not tif_file.exists(), "Source TIF should be deleted after conversion"

    def test_webp_has_content(self, tmp_path):
        from lidar_pipeline.rendering import tif_to_png
        tif_file = _make_test_tif(tmp_path)
        result = tif_to_png(tif_file, tmp_path, 5.0)
        assert result.stat().st_size > 1000  # Must be a real image


class TestApplyColormap:
    def test_symmetric_mode(self, tmp_path):
        from lidar_pipeline.rendering import COLORMAPS, tif_to_png
        # LRM uses symmetric mode
        data = np.random.default_rng(42).normal(0, 0.5, (50, 50)).astype(np.float32)
        tif_file = _make_test_tif(tmp_path, data)
        result = tif_to_png(tif_file, tmp_path, 5.0)
        assert result is not None
        assert result.exists()

    def test_percentile_mode(self, tmp_path):
        from lidar_pipeline.rendering import tif_to_png
        # Most visualizations use percentile mode
        data = np.random.default_rng(42).normal(50, 10, (50, 50)).astype(np.float32)
        tif_file = _make_test_tif(tmp_path, data)
        result = tif_to_png(tif_file, tmp_path, 5.0)
        assert result is not None
        assert result.exists()