// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

#nullable disable

using Microsoft.DotNet.Cli.Utils;

namespace Microsoft.DotNet.Cli.CommandFactory.CommandResolution;

public class PackagedCommandSpecFactoryWithCliRuntime : PackagedCommandSpecFactory
{
    public PackagedCommandSpecFactoryWithCliRuntime() : base(AddAdditionalParameters)
    {
    }

    private static void AddAdditionalParameters(string commandPath, IList<string> arguments)
    {
        if (PrefersCliRuntime(commandPath))
        {
            var runtimeConfigFile = Path.ChangeExtension(commandPath, FileNameSuffixes.RuntimeConfigJson);

            if (!File.Exists(runtimeConfigFile))
            {
                throw new GracefulException(string.Format(CliStrings.CouldNotFindToolRuntimeConfigFile,
                                                          nameof(PackagedCommandSpecFactory),
                                                          Path.GetFileName(commandPath)));
            }

            var runtimeConfig = new RuntimeConfig(runtimeConfigFile);

            var muxer = new Muxer();

            Version currentFrameworkSimpleVersion = GetVersionWithoutPrerelease(muxer.SharedFxVersion);
            Version toolFrameworkSimpleVersion = GetVersionWithoutPrerelease(runtimeConfig.Framework.Version);

            if (currentFrameworkSimpleVersion.Major != toolFrameworkSimpleVersion.Major)
            {
                Reporter.Verbose.WriteLine(
                    string.Format(
                        CliStrings.IgnoringPreferCLIRuntimeFile,
                        nameof(PackagedCommandSpecFactory),
                        runtimeConfig.Framework.Version,
                        muxer.SharedFxVersion));
            }
            else
            {
                arguments.Add("--fx-version");
                arguments.Add(muxer.SharedFxVersion);
            }
        }
    }

    private static Version GetVersionWithoutPrerelease(string version)
    {
        int dashOrPlusIndex = version.IndexOfAny(['-', '+']);

        if (dashOrPlusIndex >= 0)
        {
            version = version.Substring(0, dashOrPlusIndex);
        }

        return new Version(version);
    }

    private static bool PrefersCliRuntime(string commandPath)
    {
        var libTFMPackageDirectory = Path.GetDirectoryName(commandPath);
        var packageDirectory = Path.Combine(libTFMPackageDirectory, "..", "..");
        var preferCliRuntimePath = Path.Combine(packageDirectory, "prefercliruntime");

        Reporter.Verbose.WriteLine(
            string.Format(
                CliStrings.LookingForPreferCliRuntimeFile,
                nameof(PackagedCommandSpecFactory),
                preferCliRuntimePath));

        return File.Exists(preferCliRuntimePath);
    }
}