// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Reflection;

namespace Microsoft.Extensions.CommandLineUtils
{
    internal static class CommandLineApplicationExtensions
    {
        public static CommandOption HelpOption(this CommandLineApplication app)
            => app.HelpOption("-?|-h|--help");

        public static CommandOption VerboseOption(this CommandLineApplication app)
            => app.Option("-v|--verbose", "Show verbose output", CommandOptionType.NoValue, inherited: true);

        public static void OnExecute(this CommandLineApplication app, Action action)
            => app.OnExecute(() =>
                {
                    action();
                    return 0;
                });

        public static void VersionOptionFromAssemblyAttributes(this CommandLineApplication app, Assembly assembly)
            => app.VersionOption("--version", GetInformationalVersion(assembly));

        private static string GetInformationalVersion(Assembly assembly)
        {
            var attribute = assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>();

            var versionAttribute = attribute == null
                ? assembly.GetName().Version.ToString()
                : attribute.InformationalVersion;

            return versionAttribute;
        }
    }
}