using BenchmarkDotNet.Attributes;

namespace Just.PreciseMath.Benchmarks;

/// <summary>Measures independent array operations, including loads, stores, and loop overhead.</summary>
[MemoryDiagnoser]
[CategoriesColumn]
public class ArithmeticThroughputBenchmarks
{
    private DoubleDouble[] _left = [];
    private DoubleDouble[] _right = [];
    private double[] _scalarLeft = [];
    private double[] _scalarRight = [];
    private readonly DoubleDouble[] _results = new DoubleDouble[ArithmeticInputs.Count];
    private readonly double[] _doubleResults = new double[ArithmeticInputs.Count];

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

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

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

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

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

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Addition")]
    public double[] DoubleAdd()
    {
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            _doubleResults[i] = _scalarLeft[i] + _scalarRight[i];
        }
        return _doubleResults;
    }

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

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

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

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Subtraction")]
    public double[] DoubleSubtract()
    {
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            _doubleResults[i] = _scalarLeft[i] - _scalarRight[i];
        }
        return _doubleResults;
    }

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

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

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

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Multiplication")]
    public double[] DoubleMultiply()
    {
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            _doubleResults[i] = _scalarLeft[i] * _scalarRight[i];
        }
        return _doubleResults;
    }

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

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

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

    [Benchmark(OperationsPerInvoke = ArithmeticInputs.Count), BenchmarkCategory("Division")]
    public double[] DoubleDivide()
    {
        for (int i = 0; i < ArithmeticInputs.Count; i++)
        {
            _doubleResults[i] = _scalarLeft[i] / _scalarRight[i];
        }
        return _doubleResults;
    }
}