using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Sql.Common;

/// <summary>The query shape that serves an aggregate. One query per family.</summary>
public enum AggregateFamily
{
    /// <summary>Average / Minimum / Maximum / Count / Range / PercentGood / PercentBad: one GROUP BY.</summary>
    Simple,

    /// <summary>Start / End / Delta: first + last usable sample per bucket.</summary>
    StartEnd,

    /// <summary>MinimumActualTime / MaximumActualTime: extreme usable sample per bucket, ties ⇒ earliest.</summary>
    ActualTime,

    /// <summary>
    ///     TimeAverage / TimeAverage2 / Total / Total2 / Interpolative: Part 13 time-weighted, with bounding values.
    ///     The backend streams the window's samples plus the bounding rows and <see cref="TimeWeightedAggregator"/>
    ///     evaluates them (identically for every backend).
    /// </summary>
    TimeWeighted,
}

/// <summary>Which aggregates the SQL historian backends serve, and by which family.</summary>
public static class AggregateFamilies
{
    /// <summary>The family that serves <paramref name="aggregate"/>, or null when the backends do not.</summary>
    /// <param name="aggregate">Requested aggregate.</param>
    /// <returns>The family, or null for an unsupported aggregate.</returns>
    public static AggregateFamily? FamilyOf(HistoryAggregateType aggregate) => aggregate switch
    {
        HistoryAggregateType.Average or HistoryAggregateType.Minimum or HistoryAggregateType.Maximum
            or HistoryAggregateType.Count or HistoryAggregateType.Range
            or HistoryAggregateType.PercentGood or HistoryAggregateType.PercentBad => AggregateFamily.Simple,
        HistoryAggregateType.Start or HistoryAggregateType.End or HistoryAggregateType.Delta => AggregateFamily.StartEnd,
        HistoryAggregateType.MinimumActualTime or HistoryAggregateType.MaximumActualTime => AggregateFamily.ActualTime,
        HistoryAggregateType.TimeAverage or HistoryAggregateType.TimeAverage2 or HistoryAggregateType.Total
            or HistoryAggregateType.Total2 or HistoryAggregateType.Interpolative => AggregateFamily.TimeWeighted,
        _ => null,
    };
}