using System.Reflection;
using InterfaceForward.Application.Contracts.ForwardCore;
using Microsoft.CodeAnalysis;

namespace InterfaceForward.Application.ForwardCore;

internal static class NatashaScriptCompiler
{
    public static Action<ForwardCoreContext> CompileAction(string script)
    {
        var method = Compile(script, "void");
        return method.CreateDelegate<Action<ForwardCoreContext>>();
    }

    public static Func<ForwardCoreContext, Task> CompileAsyncFunc(string script)
    {
        var method = Compile(script, "async System.Threading.Tasks.Task");
        return method.CreateDelegate<Func<ForwardCoreContext, Task>>();
    }

    static MethodInfo Compile(string script, string returnType)
    {
        var typeName = "Script_" + Guid.NewGuid().ToString("N");
        var code = $$"""
                     using System;
                     using System.Collections.Generic;
                     using System.Linq;
                     using System.Threading.Tasks;
                     using InterfaceForward.Application.Contracts.ForwardCore;
                     using InterfaceForward.Domain.Shared;
                     using InterfaceForward.Domain.Shared.Dtos;
                     using InterfaceForward.Domain.Shared.Enum;
                     using Newtonsoft.Json.Linq;

                     public static class {{typeName}}
                     {
                        public static {{returnType}} Run(ForwardCoreContext obj)
                        {
                            var context = obj;
                     {{script}}
                        }
                     }
                     """;

        var assembly = new AssemblyCSharpBuilder()
            .UseRandomDomain()
            .WithSpecifiedReferences(GetMetadataReferences())
            .Add(code)
            .GetAssembly();

        return assembly
            .GetType(typeName, throwOnError: true)!
            .GetMethod("Run", BindingFlags.Public | BindingFlags.Static)!;
    }

    static IEnumerable<MetadataReference> GetMetadataReferences()
    {
        var paths = new HashSet<string>(StringComparer.OrdinalIgnoreCase);

        if (AppContext.GetData("TRUSTED_PLATFORM_ASSEMBLIES") is string trustedPlatformAssemblies)
        {
            foreach (var path in trustedPlatformAssemblies.Split(Path.PathSeparator))
            {
                AddPath(path);
            }
        }

        foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
        {
            AddPath(assembly.Location);
        }

        return paths.Select(path => MetadataReference.CreateFromFile(path));

        void AddPath(string? path)
        {
            if (!string.IsNullOrWhiteSpace(path) && File.Exists(path))
            {
                paths.Add(path);
            }
        }
    }
}