using System.IO.Compression;
using System.Text;
using Xunit;

namespace LehrerApp.Api.Tests;

public sealed class DwdWeatherServiceTests
{
    [Fact]
    public void ParseStationCatalog_LiestFestbreitenformatUndFindetNaechsteStation()
    {
        const string catalog = """
            ID    ICAO NAME                 LAT    LON     ELEV
            ----- ---- -------------------- -----  ------- -----
            10641 EDDF OFFENBACH-WETTERPARK 50.08    8.78   119
            10382 EDDT BERLIN-TEGEL         52.56   13.31    37
            """;

        var stations = DwdWeatherService.ParseStationCatalog(catalog);
        var nearest = DwdWeatherService.FindNearestStation(stations, 50.1, 8.7);

        Assert.Equal(2, stations.Count);
        Assert.Equal("10641", nearest!.Id);
        Assert.Equal("OFFENBACH-WETTERPARK", nearest.Name);
    }

    [Fact]
    public void ParseMosmix_KonvertiertEinheitenUndBehaeltFehlwerteAlsNull()
    {
        var now = DateTime.UtcNow.AddHours(1).ToString("yyyy-MM-dd'T'HH:00:00.000'Z'");
        var kml = $$"""
            <?xml version="1.0" encoding="UTF-8"?>
            <kml:kml xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:dwd="https://opendata.dwd.de/weather/lib/pointforecast_dwd_extension_V1_0.xsd">
              <kml:Document><kml:ExtendedData><dwd:ProductDefinition>
                <dwd:IssueTime>2026-08-23T15:00:00Z</dwd:IssueTime>
                <dwd:ForecastTimeSteps><dwd:TimeStep>{{now}}</dwd:TimeStep></dwd:ForecastTimeSteps>
              </dwd:ProductDefinition></kml:ExtendedData><kml:Placemark><kml:ExtendedData>
                <dwd:Forecast dwd:elementName="TTT"><dwd:value>293.15</dwd:value></dwd:Forecast>
                <dwd:Forecast dwd:elementName="FF"><dwd:value>5</dwd:value></dwd:Forecast>
                <dwd:Forecast dwd:elementName="FX1"><dwd:value>-</dwd:value></dwd:Forecast>
                <dwd:Forecast dwd:elementName="RR1c"><dwd:value>1.25</dwd:value></dwd:Forecast>
                <dwd:Forecast dwd:elementName="Neff"><dwd:value>75</dwd:value></dwd:Forecast>
                <dwd:Forecast dwd:elementName="ww"><dwd:value>61</dwd:value></dwd:Forecast>
              </kml:ExtendedData></kml:Placemark></kml:Document>
            </kml:kml>
            """;

        var parsed = DwdWeatherService.ParseMosmix(Zip("forecast.kml", kml));
        var hour = Assert.Single(parsed.Hours);

        Assert.Equal(20, hour.TemperatureC);
        Assert.Equal(18, hour.WindSpeedKmh);
        Assert.Null(hour.WindGustKmh);
        Assert.Equal(1.3, hour.PrecipitationMm);
        Assert.Equal(61, hour.WeatherCode);
    }

    [Fact]
    public void ParseMosmix_LiefertMehrAlsDreiTageFuerFolgewoche()
    {
        var start = DateTime.UtcNow.AddHours(1);
        var timeSteps = string.Join("", Enumerable.Range(0, 100)
            .Select(i => $"<dwd:TimeStep>{start.AddHours(i):yyyy-MM-dd'T'HH:mm:ss'Z'}</dwd:TimeStep>"));
        var values = string.Join(' ', Enumerable.Repeat("293.15", 100));
        var kml = $$"""
            <?xml version="1.0" encoding="UTF-8"?>
            <kml:kml xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:dwd="https://opendata.dwd.de/weather/lib/pointforecast_dwd_extension_V1_0.xsd">
              <kml:Document><kml:ExtendedData><dwd:ProductDefinition>
                <dwd:ForecastTimeSteps>{{timeSteps}}</dwd:ForecastTimeSteps>
              </dwd:ProductDefinition></kml:ExtendedData><kml:Placemark><kml:ExtendedData>
                <dwd:Forecast dwd:elementName="TTT"><dwd:value>{{values}}</dwd:value></dwd:Forecast>
              </kml:ExtendedData></kml:Placemark></kml:Document>
            </kml:kml>
            """;

        var parsed = DwdWeatherService.ParseMosmix(Zip("forecast.kml", kml));

        Assert.Equal(100, parsed.Hours.Count);
    }

    [Fact]
    public void ParseCapArchive_OrdnetWarnpolygonGeografischZu()
    {
        var xml = """
            <alert xmlns="urn:oasis:names:tc:emergency:cap:1.2">
              <identifier>warnung-1</identifier><status>Actual</status>
              <info><language>de-DE</language><event>GEWITTER</event><severity>Severe</severity>
                <onset>2026-08-23T18:00:00Z</onset><expires>2099-08-23T20:00:00Z</expires>
                <headline>Amtliche Warnung</headline><description>Test</description>
                <area><polygon>50.0,8.0 50.0,9.0 51.0,9.0 51.0,8.0 50.0,8.0</polygon></area>
              </info>
            </alert>
            """;

        var warning = Assert.Single(DwdWeatherService.ParseCapArchive(
            Zip("warning.xml", xml), DateTime.UtcNow));

        Assert.True(DwdWeatherService.PointInPolygon(warning.Polygons[0], 50.5, 8.5));
        Assert.False(DwdWeatherService.PointInPolygon(warning.Polygons[0], 52.0, 8.5));
        Assert.Equal("GEWITTER", warning.Warning.Event);
    }

    private static byte[] Zip(string fileName, string content)
    {
        using var memory = new MemoryStream();
        using (var archive = new ZipArchive(memory, ZipArchiveMode.Create, leaveOpen: true))
        {
            var entry = archive.CreateEntry(fileName);
            using var writer = new StreamWriter(entry.Open(), new UTF8Encoding(false));
            writer.Write(content);
        }
        return memory.ToArray();
    }
}