// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
 
namespace Microsoft.VisualStudio.Razor.IntegrationTests;
 
internal static class RazorDebug
{
    /// <inheritdoc cref="Debug.Assert(bool)"/>
    [Conditional("DEBUG")]
    public static void Assert([DoesNotReturnIf(false)] bool b) => Debug.Assert(b);
 
    /// <inheritdoc cref="Debug.Assert(bool, string)"/>
    [Conditional("DEBUG")]
    public static void Assert([DoesNotReturnIf(false)] bool b, string message)
        => Debug.Assert(b, message);
 
    [Conditional("DEBUG")]
    public static void AssertNotNull<T>([NotNull] T value)
    {
        Assert(value is object, "Unexpected null reference");
    }
 
    /// <summary>
    /// Generally <see cref="Debug.Assert(bool)"/> is a sufficient method for enforcing DEBUG
    /// only invariants in our code. When it triggers that provides a nice stack trace for
    /// investigation. Generally that is enough.
    ///
    /// <para>There are cases for which a stack is not enough and we need a full heap dump to
    /// investigate the failure. This method takes care of that. The behavior is that when running
    /// in our CI environment if the assert triggers we will rudely crash the process and
    /// produce a heap dump for investigation.</para>
    /// </summary>
    [Conditional("DEBUG")]
    internal static void AssertOrFailFast([DoesNotReturnIf(false)] bool condition, string? message = null)
    {
        if (!condition)
        {
            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("HELIX_DUMP_FOLDER")))
            {
                message ??= $"{nameof(AssertOrFailFast)} failed";
                var stackTrace = new StackTrace();
                Console.WriteLine(message);
                Console.WriteLine(stackTrace);
 
                // Use FailFast so that the process fails rudely and goes through
                // windows error reporting (on Windows at least). This will allow our
                // Helix environment to capture crash dumps for future investigation
                Environment.FailFast(message);
            }
            else
            {
                Debug.Assert(false, message);
            }
        }
    }
}