// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using System.Diagnostics;
using System.Runtime.CompilerServices;
using Xunit.Abstractions;

namespace SixLabors.ImageSharp.Tests;

/// <summary>
/// Utility class to measure the execution of an operation. It can be used either by inheritance or by composition.
/// </summary>
public class MeasureFixture
{
    /// <summary>
    /// Value indicating whether printing is enabled.
    /// </summary>
    protected bool enablePrinting = true;

    /// <summary>
    /// Measures and prints the execution time of an <see cref="Action{T}"/>, executed multiple times.
    /// </summary>
    /// <param name="times">A value indicating how many times to run the action</param>
    /// <param name="action">The <see cref="Action{T}"/> to execute</param>
    /// <param name="operationName">The name of the operation to print to the output</param>
    public void Measure(int times, Action action, [CallerMemberName] string operationName = null)
    {
        if (this.enablePrinting)
        {
            this.Output?.WriteLine($"{operationName} X {times} ...");
        }

        Stopwatch sw = Stopwatch.StartNew();

        for (int i = 0; i < times; i++)
        {
            action();
        }

        sw.Stop();
        if (this.enablePrinting)
        {
            this.Output?.WriteLine($"{operationName} finished in {sw.ElapsedMilliseconds} ms");
        }
    }

    /// <summary>
    /// Initializes a new instance of <see cref="MeasureFixture"/>
    /// </summary>
    /// <param name="output">A <see cref="ITestOutputHelper"/> instance to print the results </param>
    public MeasureFixture(ITestOutputHelper output)
    {
        this.Output = output;
    }

    protected ITestOutputHelper Output { get; }
}

public class MeasureGuard : IDisposable
{
    private readonly string operation;

    private readonly Stopwatch stopwatch = new();

    public MeasureGuard(ITestOutputHelper output, string operation)
    {
        this.operation = operation;
        this.Output = output;
        this.Output.WriteLine(operation + " ...");
        this.stopwatch.Start();
    }

    private ITestOutputHelper Output { get; }

    public void Dispose()
    {
        this.stopwatch.Stop();
        this.Output.WriteLine($"{this.operation} completed in {this.stopwatch.ElapsedMilliseconds}ms");
    }
}