"""Tests for visualization functions.

Each test creates a small synthetic DEM and runs a visualization function,
checking that it produces a valid output file.
"""

import numpy as np
import pytest
from pathlib import Path


# --- Core terrain visualizations (no GPU required) ---

class TestHillshade:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_hillshade
        result = generate_hillshade(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()
        assert result.suffix == ".tif"

    def test_output_values_valid(self, synthetic_dem, tmp_output_dir):
        import rasterio
        from lidar_pipeline.visualizations import generate_hillshade
        result = generate_hillshade(synthetic_dem, "test", tmp_output_dir, 5.0)
        with rasterio.open(result) as src:
            data = src.read(1)
            assert data.shape[0] > 0
            assert np.nanmin(data) >= 0
            assert np.nanmax(data) <= 1


class TestSlope:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_slope
        result = generate_slope(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()

    def test_slope_values_degrees(self, synthetic_dem, tmp_output_dir):
        import rasterio
        from lidar_pipeline.visualizations import generate_slope
        result = generate_slope(synthetic_dem, "test", tmp_output_dir, 5.0)
        with rasterio.open(result) as src:
            data = src.read(1)
            assert np.nanmin(data) >= 0
            assert np.nanmax(data) <= 90


# --- GPU-accelerated visualizations ---

class TestSVF:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_svf
        result = generate_svf(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()

    def test_svf_values_0_1(self, synthetic_dem, tmp_output_dir):
        import rasterio
        from lidar_pipeline.visualizations import generate_svf
        result = generate_svf(synthetic_dem, "test", tmp_output_dir, 5.0)
        with rasterio.open(result) as src:
            data = src.read(1)
            valid = data[~np.isnan(data)]
            assert np.nanmin(valid) >= 0
            assert np.nanmax(valid) <= 1


class TestOpenness:
    def test_positive_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_openness
        result = generate_openness(synthetic_dem, "test", tmp_output_dir, 5.0, positive=True)
        assert result is not None
        assert result.exists()

    def test_negative_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_openness
        result = generate_openness(synthetic_dem, "test", tmp_output_dir, 5.0, positive=False)
        assert result is not None
        assert result.exists()


class TestMSLRM:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_mslrm
        result = generate_mslrm(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()


class TestSAILORE:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_sailore
        result = generate_sailore(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()


class TestRoughness:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_roughness
        result = generate_roughness(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()

    def test_roughness_non_negative(self, synthetic_dem, tmp_output_dir):
        import rasterio
        from lidar_pipeline.visualizations import generate_roughness
        result = generate_roughness(synthetic_dem, "test", tmp_output_dir, 5.0)
        with rasterio.open(result) as src:
            data = src.read(1)
            # Standard deviation is always >= 0
            assert np.nanmin(data) >= 0


class TestWavelet:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_wavelet
        result = generate_wavelet(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()


class TestFlowAccumulation:
    def test_generates_tif(self, synthetic_dem, tmp_output_dir):
        from lidar_pipeline.visualizations import generate_flow_accumulation
        result = generate_flow_accumulation(synthetic_dem, "test", tmp_output_dir, 5.0)
        assert result is not None
        assert result.exists()

    def test_flow_log_values(self, synthetic_dem, tmp_output_dir):
        import rasterio
        from lidar_pipeline.visualizations import generate_flow_accumulation
        result = generate_flow_accumulation(synthetic_dem, "test", tmp_output_dir, 5.0)
        with rasterio.open(result) as src:
            data = src.read(1)
            # log10(x) >= 0 for x >= 1
            valid = data[~np.isnan(data)]
            assert np.nanmin(valid) >= 0


class TestRayTrace:
    def test_rays_are_traced(self, synthetic_dem, tmp_output_dir):
        """Verify _ray_trace_horizons returns expected shapes."""
        from lidar_pipeline.visualizations import _ray_trace_horizons, _prepare_dem_for_raycast
        import rasterio
        with rasterio.open(synthetic_dem) as src:
            dem_np = src.read(1)
        rows, cols = dem_np.shape
        # Create a simple filled DEM for testing
        import numpy as np
        filled = np.nan_to_num(dem_np, nan=0)
        # Test with numpy (no GPU)
        pos, neg = _ray_trace_horizons(
            filled, rows, cols, 5.0, n_dirs=4, max_dist=10, radii_m=[25, 50]
        )
        assert pos.shape == (4, 2, rows, cols)
        assert neg.shape == (4, 2, rows, cols)