using MeterVault.Core.Domain;

namespace MeterVault.Core.Normalization;

/// <summary>
/// The immutable, infrastructure-free view of a meter that the normalization engine needs.
/// Infrastructure projects a <see cref="Meter"/> (+ optional <see cref="Tank"/>) into this.
/// </summary>
public sealed record MeterConfig
{
    public required int MeterId { get; init; }

    public required MeterMode Mode { get; init; }

    public required string Unit { get; init; }

    /// <summary>Register baseline for a newly installed meter (SDD §7.1). Default 0.</summary>
    public double InitialBaseline { get; init; }

    /// <summary>Tank/runtime configuration for consumable_balance and runtime_counter meters.</summary>
    public TankConfig? Tank { get; init; }

    /// <summary>Expression + referenced meters for virtual meters.</summary>
    public VirtualSpec? Virtual { get; init; }
}

/// <summary>Consumable/runtime parameters (SDD §5.3 <c>tank</c>).</summary>
public sealed record TankConfig
{
    public double Capacity { get; init; }

    public TankRateMode RateMode { get; init; } = TankRateMode.Empirical;

    /// <summary>Litres per runtime-hour when <see cref="RateMode"/> is Fixed.</summary>
    public double? FixedRate { get; init; }

    /// <summary>Physical-level (cm) → volume curve. Present when dipstick readings are recorded.</summary>
    public CalibrationCurve? Calibration { get; init; }
}

/// <summary>A virtual meter's expression over other meters' series (SDD §7.4).</summary>
public sealed record VirtualSpec
{
    public required string Expression { get; init; }

    public IReadOnlyList<int> ReferencedMeterIds { get; init; } = [];
}