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

namespace MeterVault.Core.Tests;

public sealed class RuntimeAndTankTests
{
    private readonly INormalizationEngine _engine = NormalizationEngine.CreateDefault();

    [Fact]
    public void Runtime_counter_multiplies_delta_hours_by_fixed_rate()
    {
        var ctx = new NormalizationContext
        {
            Meter = new MeterConfig
            {
                MeterId = 20,
                Mode = MeterMode.RuntimeCounter,
                Unit = "L",
                InitialBaseline = 7785,
                Tank = new TankConfig { Capacity = 7000, RateMode = TankRateMode.Fixed, FixedRate = 2.0 },
            },
            Readings = [Reading(20, Month(2023, 1), 7785), Reading(20, Month(2023, 2), 7952)],
        };

        var result = _engine.Normalize(ctx);

        // Δhours: 0, then 167 × 2.0 L/h = 334 L.
        Assert.Equal([0d, 334d], result.Select(c => c.Amount));
    }

    [Fact]
    public void Tank_consumption_is_level_delta_between_dipsticks()
    {
        // Linear calibration 7000 L / 150 cm ≈ 46.667 L/cm (SDD §2.4).
        var calibration = new CalibrationCurve(7000d / 150d);
        var ctx = new NormalizationContext
        {
            Meter = new MeterConfig
            {
                MeterId = 30,
                Mode = MeterMode.ConsumableBalance,
                Unit = "L",
                Tank = new TankConfig { Capacity = 7000, Calibration = calibration },
            },
            Events =
            [
                Delivery(30, Month(2020, 9), 3500),          // pre-first-level delivery: absorbed
                TankLevelCm(30, Month(2022, 9), 35),          // first level: no consumption emitted
                TankLevelCm(30, Month(2022, 10), 34),         // ~46.7 L drawn
                TankLevelCm(30, Month(2022, 11), 27),         // ~326.7 L drawn
            ],
        };

        var result = _engine.Normalize(ctx);

        Assert.Equal(2, result.Count);
        Assert.Equal(46.7, result[0].Amount, 1);
        Assert.Equal(326.7, result[1].Amount, 1);
    }

    [Fact]
    public void Delivery_between_dipsticks_reconciles_into_the_balance()
    {
        var calibration = new CalibrationCurve(7000d / 150d);
        var ctx = new NormalizationContext
        {
            Meter = new MeterConfig
            {
                MeterId = 30,
                Mode = MeterMode.ConsumableBalance,
                Unit = "L",
                Tank = new TankConfig { Capacity = 7000, Calibration = calibration },
            },
            Events =
            [
                TankLevelCm(30, Month(2022, 9), 20),   // 933.3 L
                Delivery(30, Month(2022, 10), 2000),
                TankLevelCm(30, Month(2022, 11), 50),  // 2333.3 L
            ],
        };

        var result = _engine.Normalize(ctx);

        // consumption = 933.3 + 2000 − 2333.3 = 600.
        Assert.Single(result);
        Assert.Equal(600d, result[0].Amount, 1);
    }
}