// 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 Newtonsoft.Json;
using Newtonsoft.Json.Linq;
 
namespace Microsoft.DotNet.Build.Tasks
{
    public class PublishMutationUtilities
    {
        public static void ChangeEntryPointLibraryName(string depsFile, string newName)
        {
            JToken deps;
            using (var file = File.OpenText(depsFile))
            using (JsonTextReader reader = new(file))
            {
                deps = JToken.ReadFrom(reader);
            }
 
            string version = null;
            foreach (JProperty target in deps["targets"])
            {
                var targetLibrary = target.Value.Children<JProperty>().FirstOrDefault();
                if (targetLibrary == null)
                {
                    continue;
                }
                version = targetLibrary.Name.Substring(targetLibrary.Name.IndexOf('/') + 1);
                if (newName == null)
                {
                    targetLibrary.Remove();
                }
                else
                {
                    targetLibrary.Replace(new JProperty(newName + '/' + version, targetLibrary.Value));
                }
            }
            if (version != null)
            {
                var library = deps["libraries"].Children<JProperty>().First();
                if (newName == null)
                {
                    library.Remove();
                }
                else
                {
                    library.Replace(new JProperty(newName + '/' + version, library.Value));
                }
                using (var file = File.CreateText(depsFile))
                using (var writer = new JsonTextWriter(file) { Formatting = Formatting.Indented })
                {
                    deps.WriteTo(writer);
                }
            }
        }
    }
}