using MeterVault.Core.Domain;
using MeterVault.Core.Normalization;
using static MeterVault.Core.Tests.TestData;

namespace MeterVault.Core.Tests;

/// <summary>
/// The electricity derived columns are data-driven virtual expressions, not hardcoded formulas
/// (SDD §2.2, §7.4): Netz Einsparung = Haus − Netz, Anlage Eigenverbrauch = Erzeugung − Einsparung.
/// </summary>
public sealed class VirtualMeterTests
{
    private readonly INormalizationEngine _engine = NormalizationEngine.CreateDefault();

    private static Consumption Cons(int meterId, DateTimeOffset time, double amount) => new()
    {
        MeterId = meterId,
        Time = time,
        Amount = amount,
        Kind = ConsumptionKind.Consumption,
        Quality = ReadingQuality.Imported,
    };

    [Fact]
    public void Netz_einsparung_is_haus_minus_netz()
    {
        var oct = Month(2022, 10);
        var nov = Month(2022, 11);
        var ctx = new NormalizationContext
        {
            Meter = new MeterConfig
            {
                MeterId = 100,
                Mode = MeterMode.Virtual,
                Unit = "kWh",
                Virtual = new VirtualSpec { Expression = "m1 - m2", ReferencedMeterIds = [1, 2] },
            },
            ReferencedSeries = new Dictionary<int, IReadOnlyList<Consumption>>
            {
                [1] = [Cons(1, oct, 411), Cons(1, nov, 742)], // Haus Verbrauch
                [2] = [Cons(2, oct, 416), Cons(2, nov, 832)], // Netz Verbrauch
            },
        };

        var result = _engine.Normalize(ctx);

        Assert.Equal([-5d, -90d], result.Select(c => c.Amount));
    }

    [Fact]
    public void Eigenverbrauch_is_erzeugung_minus_einsparung()
    {
        var oct = Month(2022, 10);
        var ctx = new NormalizationContext
        {
            Meter = new MeterConfig
            {
                MeterId = 101,
                Mode = MeterMode.Virtual,
                Unit = "kWh",
                Virtual = new VirtualSpec { Expression = "m50 - m100", ReferencedMeterIds = [50, 100] },
            },
            ReferencedSeries = new Dictionary<int, IReadOnlyList<Consumption>>
            {
                [50] = [Cons(50, oct, 76)],   // Solar Erzeugung
                [100] = [Cons(100, oct, -5)], // Netz Einsparung (from the previous test)
            },
        };

        var result = _engine.Normalize(ctx);

        // 76 − (−5) = 81 (Anlage Eigenverbrauch Okt 2022).
        Assert.Equal([81d], result.Select(c => c.Amount));
    }
}