"""tests/test_io.py —— IO 读写单元测试。"""

import pytest
import geopandas as gpd
from pathlib import Path

from geo_tools.io.readers import read_vector, read_gpkg, list_gpkg_layers, read_csv_points
from geo_tools.io.writers import write_vector, write_gpkg, write_csv


class TestReadVector:
    def test_read_geojson(self, tmp_geojson_path):
        gdf = read_vector(tmp_geojson_path)
        assert isinstance(gdf, gpd.GeoDataFrame)
        assert len(gdf) == 3
        assert gdf.crs is not None

    def test_read_with_crs_reprojection(self, tmp_geojson_path):
        gdf = read_vector(tmp_geojson_path, crs="EPSG:3857")
        assert gdf.crs.to_epsg() == 3857

    def test_read_nonexistent_raises(self, tmp_path):
        with pytest.raises(FileNotFoundError):
            read_vector(tmp_path / "nonexistent.geojson")

    def test_read_unsupported_format_raises(self, tmp_path):
        bad_file = tmp_path / "data.xyz"
        bad_file.write_text("dummy")
        with pytest.raises(ValueError, match="不支持"):
            read_vector(bad_file)


class TestWriteReadRoundtrip:
    def test_geojson_roundtrip(self, sample_points_gdf, tmp_output_dir):
        out = tmp_output_dir / "out.geojson"
        write_vector(sample_points_gdf, out)
        loaded = read_vector(out)
        assert len(loaded) == len(sample_points_gdf)
        assert list(loaded.columns) == list(sample_points_gdf.columns)

    def test_gpkg_roundtrip(self, sample_points_gdf, tmp_output_dir):
        out = tmp_output_dir / "out.gpkg"
        write_gpkg(sample_points_gdf, out, layer="points")
        loaded = read_gpkg(out, layer="points")
        assert len(loaded) == len(sample_points_gdf)

    def test_gpkg_multiple_layers(self, sample_points_gdf, sample_polygon_gdf, tmp_output_dir):
        out = tmp_output_dir / "multi.gpkg"
        write_gpkg(sample_points_gdf, out, layer="points")
        write_gpkg(sample_polygon_gdf, out, layer="polygons", mode="a")
        layers = list_gpkg_layers(out)
        assert "points" in layers
        assert "polygons" in layers

    def test_csv_roundtrip(self, sample_points_gdf, tmp_output_dir):
        out = tmp_output_dir / "out.csv"
        write_csv(sample_points_gdf, out)
        # CSV 写出的是 WKT geometry 列，用 pandas 读回验证
        import pandas as pd
        df = pd.read_csv(out)
        assert "geometry" in df.columns          # 存在 WKT 几何列
        assert len(df) == len(sample_points_gdf)  # 行数一致
        # 再用 read_csv_points 以 WKT 模式读回
        from geo_tools.io.readers import _read_csv_vector
        from pathlib import Path
        gdf_back = _read_csv_vector(Path(out), wkt_col="geometry")
        assert len(gdf_back) == len(sample_points_gdf)


class TestReadCsvPoints:
    def test_read_csv_with_latlon(self, tmp_path):
        import pandas as pd
        csv_path = tmp_path / "points.csv"
        pd.DataFrame({
            "longitude": [116.4, 121.5],
            "latitude": [39.9, 31.2],
            "name": ["北京", "上海"],
        }).to_csv(csv_path, index=False)
        gdf = read_csv_points(csv_path)
        assert len(gdf) == 2
        assert gdf.crs.to_epsg() == 4326