using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using static ZB.MOM.WW.OtOpcUa.Driver.Historian.Sql.Common.Tests.Fixture;

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

/// <summary>
///     Direct tests of the aggregate evaluator over hand-built bucket rows for tag A, 20 s intervals from T0, window
///     [t0, t0+80s): B0 = {10, 20}; B1 = {Bad 30, 40}; B2 = {50}; B3 empty. Literals from the SqlServer
///     <c>ProcessedReadTests</c>.
/// </summary>
public sealed class AggregateEvaluatorTests
{
    private static readonly DateTime Now = At(3600);

    private static Dictionary<long, BucketRow> RowsA(bool maximum = false) => new()
    {
        [0] = new BucketRow
        {
            Bucket = 0, Total = 2, Usable = 2, Good = 2, Bad = 0, NonNumeric = 0, Avg = 15, Min = 10, Max = 20, Sum = 30,
            First = HistorianValue.FromDouble(10), Last = HistorianValue.FromDouble(20),
            Extreme = maximum ? 20 : 10, ExtremeTime = maximum ? At(10) : At(0),
        },
        [1] = new BucketRow
        {
            Bucket = 1, Total = 2, Usable = 1, Good = 1, Bad = 1, NonNumeric = 0, Avg = 40, Min = 40, Max = 40, Sum = 40,
            First = HistorianValue.FromDouble(40), Last = HistorianValue.FromDouble(40), Extreme = 40, ExtremeTime = At(30),
        },
        [2] = new BucketRow
        {
            Bucket = 2, Total = 1, Usable = 1, Good = 1, Bad = 0, NonNumeric = 0, Avg = 50, Min = 50, Max = 50, Sum = 50,
            First = HistorianValue.FromDouble(50), Last = HistorianValue.FromDouble(50), Extreme = 50, ExtremeTime = At(40),
        },
    };

    private static IReadOnlyList<DataValueSnapshot> ReadA(HistoryAggregateType agg, bool maximum = false)
    {
        var plan = BucketPlan.Create(At(0), At(80), TimeSpan.FromSeconds(20));
        var evaluated = RowsA(maximum).ToDictionary(kv => kv.Key,
            kv => AggregateEvaluator.Evaluate(agg, kv.Value, plan.BucketStart(kv.Key), Now));
        return plan.Assemble(evaluated, t => AggregateEvaluator.NoData(t, Now));
    }

    [Theory]
    [InlineData(HistoryAggregateType.Average, 15d, 40d, 50d)]
    [InlineData(HistoryAggregateType.Minimum, 10d, 40d, 50d)]
    [InlineData(HistoryAggregateType.Maximum, 20d, 40d, 50d)]
    [InlineData(HistoryAggregateType.Total, 30d, 40d, 50d)]
    [InlineData(HistoryAggregateType.Start, 10d, 40d, 50d)]
    [InlineData(HistoryAggregateType.End, 20d, 40d, 50d)]
    [InlineData(HistoryAggregateType.Delta, 10d, 0d, 0d)]
    [InlineData(HistoryAggregateType.Range, 10d, 0d, 0d)]
    public void Numeric_aggregates_over_hand_built_bucket_rows(HistoryAggregateType agg, double b0, double b1, double b2)
    {
        var s = ReadA(agg);
        s.Count.ShouldBe(4);
        s.Select(x => x.Value).ShouldBe([b0, b1, b2, null]);
        s.Select(x => x.StatusCode).ShouldBe([GoodCalc, UncertainCalc, GoodCalc, NoDataCalc]);
        s.Select(x => x.SourceTimestampUtc).ShouldBe([At(0), At(20), At(40), At(60)]);
    }

    [Fact]
    public void Count_counts_usable_samples_as_int()
    {
        var s = ReadA(HistoryAggregateType.Count);
        s.Select(x => x.Value).ShouldBe([(object?)2, 1, 1, null]);
        s.Select(x => x.StatusCode).ShouldBe([GoodCalc, UncertainCalc, GoodCalc, NoDataCalc]);
    }

    [Theory]
    [InlineData(HistoryAggregateType.PercentGood, 100d, 50d, 100d)]
    [InlineData(HistoryAggregateType.PercentBad, 0d, 50d, 0d)]
    public void Percent_aggregates_count_every_sample_and_stay_good(HistoryAggregateType agg, double b0, double b1, double b2)
    {
        var s = ReadA(agg);
        s.Select(x => x.Value).ShouldBe([b0, b1, b2, null]);
        s.Select(x => x.StatusCode).ShouldBe([GoodCalc, GoodCalc, GoodCalc, NoDataCalc]);
    }

    [Fact]
    public void Actual_time_aggregates_stamp_the_sample_time()
    {
        var min = ReadA(HistoryAggregateType.MinimumActualTime);
        min.Select(x => x.Value).ShouldBe([10d, 40d, 50d, null]);
        min.Select(x => x.SourceTimestampUtc).ShouldBe([At(0), At(30), At(40), At(60)]);
        min.Select(x => x.StatusCode).ShouldBe([GoodCalc, UncertainCalc, GoodCalc, NoDataCalc]);
        var max = ReadA(HistoryAggregateType.MaximumActualTime, maximum: true);
        max.Select(x => x.Value).ShouldBe([20d, 40d, 50d, null]);
        max.Select(x => x.SourceTimestampUtc).ShouldBe([At(10), At(30), At(40), At(60)]);
    }

    [Fact]
    public void A_usable_non_numeric_sample_makes_a_numeric_aggregate_invalid_inputs_but_not_count()
    {
        var row = new BucketRow { Total = 2, Usable = 2, Good = 2, NonNumeric = 1, Avg = 1, First = HistorianValue.FromString("x"),
            Last = HistorianValue.FromDouble(1) };
        var avg = AggregateEvaluator.Evaluate(HistoryAggregateType.Average, row, At(0), Now);
        avg.Value.ShouldBeNull();
        avg.StatusCode.ShouldBe(InvalidInputsCalc);
        AggregateEvaluator.Evaluate(HistoryAggregateType.Count, row, At(0), Now).Value.ShouldBe(2);
        AggregateEvaluator.Evaluate(HistoryAggregateType.Delta, row, At(0), Now).StatusCode.ShouldBe(InvalidInputsCalc);
    }

    [Fact]
    public void A_bucket_with_only_bad_samples_is_no_data_except_for_the_percentages()
    {
        var row = new BucketRow { Total = 2, Usable = 0, Good = 0, Bad = 2 };
        var avg = AggregateEvaluator.Evaluate(HistoryAggregateType.Average, row, At(0), Now);
        avg.Value.ShouldBeNull();
        avg.StatusCode.ShouldBe(NoDataCalc);
        AggregateEvaluator.Evaluate(HistoryAggregateType.PercentBad, row, At(0), Now).Value.ShouldBe(100d);
    }

    [Fact]
    public void An_unsupported_aggregate_throws_not_supported()
    {
        var ex = Should.Throw<HistoryAggregateNotSupportedException>(() =>
            AggregateEvaluator.Evaluate(HistoryAggregateType.TimeAverage, RowsA()[0], At(0), Now));
        ex.Aggregate.ShouldBe(HistoryAggregateType.TimeAverage);
    }

    [Fact]
    public void An_uncertain_sample_in_a_bucket_degrades_the_aggregate_to_uncertain()
    {
        // Two usable samples, one Good and one Uncertain, no Bad: the value is computed, the status is Uncertain.
        var row = new BucketRow { Total = 2, Usable = 2, Good = 1, Bad = 0, Avg = 15, Min = 10, Max = 20, Sum = 30 };
        var avg = AggregateEvaluator.Evaluate(HistoryAggregateType.Average, row, At(0), Now);
        avg.Value.ShouldBe(15d);
        avg.StatusCode.ShouldBe(UncertainCalc);
    }
}