using BenchmarkDotNet.Attributes;

namespace Just.PreciseMath.Benchmarks;

/// <summary>Measures bounded dependent chains; each invocation resets the seed.</summary>
[MemoryDiagnoser]
[CategoriesColumn]
public class ArithmeticLatencyBenchmarks
{
    private DoubleDouble[] _left = [];
    private DoubleDouble[] _right = [];
    private double[] _scalarRight = [];

    [Params("BothResidual", "Mixed")]
    public string Scenario { get; set; } = "BothResidual";

    [GlobalSetup]
    public void Setup()
    {
        ArithmeticInputs inputs = ArithmeticInputs.Create(Scenario, true);
        _left = inputs.Left;
        _right = inputs.Right;
        _scalarRight = Array.ConvertAll(_right, value => value.High);
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Addition")]
    public DoubleDouble DDAdd()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value + _right[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Addition")]
    public DoubleDouble DDScalarAdd()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value + _scalarRight[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Addition")]
    public DoubleDouble ScalarDDAdd()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = _scalarRight[i] + value;
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Subtraction")]
    public DoubleDouble DDSubtract()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value - _right[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Subtraction")]
    public DoubleDouble DDScalarSubtract()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value - _scalarRight[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Subtraction")]
    public DoubleDouble ScalarDDSubtract()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = _scalarRight[i] - value;
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Multiplication")]
    public DoubleDouble DDMultiply()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value * _right[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Multiplication")]
    public DoubleDouble DDScalarMultiply()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value * _scalarRight[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Multiplication")]
    public DoubleDouble ScalarDDMultiply()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = _scalarRight[i] * value;
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Division")]
    public DoubleDouble DDDivide()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value / _right[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Division")]
    public DoubleDouble DDScalarDivide()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = value / _scalarRight[i];
        }
        return value;
    }

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Division")]
    public DoubleDouble ScalarDDDivide()
    {
        DoubleDouble value = _left[0];
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            value = _scalarRight[i] / value;
        }
        return value;
    }
}