// 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.IO;
using System.Linq;
using System.Runtime.InteropServices;

namespace Microsoft.AspNetCore.Testing
{
    [AttributeUsage(AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
    public sealed class DockerOnlyAttribute : Attribute, ITestCondition
    {
        public string SkipReason { get; } = "This test can only run in a Docker container.";

        public bool IsMet
        {
            get
            {
                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                {
                    // we currently don't have a good way to detect if running in a Windows container
                    return false;
                }

                const string procFile = "/proc/1/cgroup";
                if (!File.Exists(procFile))
                {
                    return false;
                }

                var lines = File.ReadAllLines(procFile);
                // typically the last line in the file is "1:name=openrc:/docker"
                return lines.Reverse().Any(l => l.EndsWith("name=openrc:/docker", StringComparison.Ordinal));
            }
        }
    }
}
