ThreatSourceLibaray/ThreatSource.Tests/Utils/Vector3DPerformanceTests.cs

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Diagnostics;
using ThreatSource.Utils; // Assuming Vector3D is here, adjust if necessary
using System.Collections.Generic;
using System;

namespace ThreatSource.Tests.Utils
{
    [TestClass]
    public class Vector3DPerformanceTests
    {
        private const int Iterations = 1000000; // Number of iterations for performance testing

        private Vector3D CreateVector(double i)
        {
            // Helper to create slightly different vectors
            return new Vector3D(i, i + 1.5, i * 0.8);
        }

        [TestMethod]
        public void Baseline_Vector3D_Class_Performance()
        {
            // This test assumes Vector3D is currently a CLASS.
            // We will run this once, record results, then change Vector3D to struct and run again.

            Stopwatch stopwatch = new Stopwatch();
            List<Vector3D> vectors = new List<Vector3D>(Iterations);
            double totalMagnitude = 0;
            Random rand = new Random(123); // Seeded for reproducibility

            // --- Test 1: Creation Performance ---
            stopwatch.Start();
            for (int i = 0; i < Iterations; i++)
            {
                vectors.Add(CreateVector(i * rand.NextDouble()));
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] Creation of {Iterations} Vector3D instances: {stopwatch.ElapsedMilliseconds} ms");
            long creationTime = stopwatch.ElapsedMilliseconds;

            // Ensure vectors are used to prevent over-optimization by compiler
            if (vectors.Count == 0) throw new Exception("Vector list empty after creation.");

            Vector3D tempVector1 = CreateVector(10.1);
            Vector3D tempVector2 = CreateVector(20.2);

            // --- Test 2: Addition Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                tempVector1 = tempVector1 + vectors[i];
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Additions: {stopwatch.ElapsedMilliseconds} ms");
            long additionTime = stopwatch.ElapsedMilliseconds;

            // --- Test 3: Subtraction Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                tempVector1 = tempVector1 - vectors[i];
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Subtractions: {stopwatch.ElapsedMilliseconds} ms");
            long subtractionTime = stopwatch.ElapsedMilliseconds;

            // --- Test 4: Scalar Multiplication Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                tempVector1 = vectors[i] * 2.5;
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Scalar Multiplications: {stopwatch.ElapsedMilliseconds} ms");
            long scalarMultTime = stopwatch.ElapsedMilliseconds;

            // --- Test 5: Dot Product Performance ---
            double dotProductSum = 0;
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                dotProductSum += Vector3D.DotProduct(vectors[i], tempVector2);
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Dot Products: {stopwatch.ElapsedMilliseconds} ms");
            long dotProductTime = stopwatch.ElapsedMilliseconds;

            // --- Test 6: Cross Product Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                tempVector1 = Vector3D.CrossProduct(vectors[i], tempVector2);
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Cross Products: {stopwatch.ElapsedMilliseconds} ms");
            long crossProductTime = stopwatch.ElapsedMilliseconds;

            // --- Test 7: Magnitude Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                totalMagnitude += vectors[i].Magnitude();
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Magnitudes: {stopwatch.ElapsedMilliseconds} ms");
            long magnitudeTime = stopwatch.ElapsedMilliseconds;

            // --- Test 8: Normalization Performance ---
            stopwatch.Restart();
            for (int i = 0; i < Iterations; i++)
            {
                // Avoid normalizing zero vectors which might throw exceptions or return NaN
                if (vectors[i].MagnitudeSquared() > 0.00001)
                {
                    tempVector1 = vectors[i].Normalize();
                }
                else
                {
                     tempVector1 = vectors[i]; // Assign to ensure work is done
                }
            }
            stopwatch.Stop();
            Console.WriteLine($"[Baseline Class] {Iterations} Vector3D Normalizations: {stopwatch.ElapsedMilliseconds} ms");
            long normalizeTime = stopwatch.ElapsedMilliseconds;

            Console.WriteLine($"[Baseline Class] Total magnitude sum (to prevent optimization): {totalMagnitude}");
            Console.WriteLine($"[Baseline Class] Final tempVector1 (to prevent optimization): {tempVector1}");
            Console.WriteLine($"[Baseline Class] Final dotProductSum (to prevent optimization): {dotProductSum}");
            
            // For MSTest, Assert.Inconclusive can be used to output results without failing the test.
            // Alternatively, a simple Console.WriteLine at the end of the test with a summary is also fine
            // if the test isn't meant to pass/fail based on performance but just to gather data.
            // For this baseline, we'll use Assert.Inconclusive to clearly mark the output in test results.
            string resultSummary = $"Baseline performance (Vector3D as CLASS):\n" +
                                 $"Creation:        {creationTime} ms\n" +
                                 $"Addition:        {additionTime} ms\n" +
                                 $"Subtraction:     {subtractionTime} ms\n" +
                                 $"Scalar Mult:     {scalarMultTime} ms\n" +
                                 $"Dot Product:     {dotProductTime} ms\n" +
                                 $"Cross Product:   {crossProductTime} ms\n" +
                                 $"Magnitude:       {magnitudeTime} ms\n" +
                                 $"Normalization:   {normalizeTime} ms";
            Console.WriteLine(resultSummary); // Ensure it's also printed to console output for easy viewing
            Assert.Inconclusive(resultSummary); // Marks test as inconclusive and shows message in test explorer
        }
    }
}