using System.IO;
using System.Text.RegularExpressions;
using ImGuiNET;
using T3.Editor.Gui.Input;
using T3.Editor.Gui.UiHelpers;

namespace T3.Editor.Gui.Windows;

/// <summary>
///
/// Helps to convert from old operator format to new operator format
///
///
/// 
/// </summary>
///
///

// OLD:

// using T3.Core.DataTypes;
// using T3.Core.Operator;
// using T3.Core.Operator.Attributes;
// using T3.Core.Operator.Slots;
//
// namespace T3.Operators.Types.Id_cce36a29_8f66_492d_bf8f_b924fa1ae384
// {
//     public class SetContextVariableExample : Instance<SetContextVariableExample>
//     {
//         [Output(Guid = "30ec9e5d-97af-4621-9e20-ef651bfd2ec3")]
//         public readonly Slot<Command> Output = new();
//
//
//     }
// }

// NEW:
// using System.Runtime.InteropServices;
// using T3.Core.DataTypes;
// using T3.Core.Operator;
// using T3.Core.Operator.Attributes;
// using T3.Core.Operator.Slots;
//
// namespace examples.lib.exec
// {
//     [Guid("cce36a29-8f66-492d-bf8f-b924fa1ae384")]
//     public class SetContextVariableExample : Instance<SetContextVariableExample>
//     {
//         [Output(Guid = "30ec9e5d-97af-4621-9e20-ef651bfd2ec3")]
//         public readonly Slot<Command> Output = new();
//
//
//     }
// }
internal static class OperatorFormatMigrationHelper
{
    private static string _nameSpace = _defaultNameSpace;
    private static string _defaultNameSpace = "UserName.Project"; 
    
    public static void Draw()
    {
        FormInputs.AddSectionHeader("This is an internal tool for migrating operators to new versions. Use with caution.");
        var filepathModified = FormInputs.AddFilePicker("Operator Folder",
                                                        ref _otherOpDirectory,
                                                        "operator folder",
                                                        _warning,
                                                        null,
                                                        FileOperations.FilePickerTypes.Folder
                                                       );
        if (filepathModified)
        {
            _warning = Directory.Exists(_otherOpDirectory) ? null : "Please select a valid folder";
        }

        FormInputs.AddVerticalSpace();
        FormInputs.AddStringInput("NameSpace",
                                             ref _nameSpace,
                                             _defaultNameSpace,
                                             null,
                                             """
                                             Documentation missing
                                             """,
                                             _defaultNameSpace);
        
        if (ImGui.Button("Migrate Operators"))
        {
            MigrateOpsInDirectory(_otherOpDirectory);
        }
    }

    private static void MigrateOpsInDirectory(string otherOpDirectory)
    {
        if (!Directory.Exists(_otherOpDirectory))
        {
            Log.Warning($"'{otherOpDirectory}' doesn't exist");
            return;
        }
            
        var files = Directory.GetFiles(otherOpDirectory, "*.cs", SearchOption.AllDirectories);
        foreach (var filepath in files)
        {
            Log.Debug($"Scanning {filepath}...");
            var fileContent = File.ReadAllText(filepath);

            var match = Regex.Match(fileContent, @"namespace T3.Operators.Types.Id_(\w{8}_\w{4}_\w{4}_\w{4}_\w{12})");
            if (!match.Success)
            {
                Log.Warning("Namespace and ID not found");
                continue;
            }
                
            var nameSpaceGuid = match.Groups[1].Value;
            var operatorGuid = nameSpaceGuid.Replace("_", "-");

            var directory = Path.GetDirectoryName(filepath);
            if (string.IsNullOrEmpty(directory))
                continue;
                
            // Derive namespace from directory and replace the old namespace
            var nameSpace = directory.Replace(otherOpDirectory, "").Replace("\\", ".");
            if (nameSpace.StartsWith("."))
                nameSpace = nameSpace[1..];

            if (string.IsNullOrWhiteSpace(nameSpace))
            {
                nameSpace = _nameSpace;
            }
                
            var newContent = fileContent.Replace(
                                                 $"namespace T3.Operators.Types.Id_{nameSpaceGuid}",
                                                 $"namespace {nameSpace}");
                
            // Insert Guid() attribute to class
            var symbolName = Path.GetFileNameWithoutExtension(filepath);
            newContent = Regex.Replace(
                                       newContent,
                                       $@"public\s+(sealed\s+)?class\s+{Regex.Escape(symbolName)}",
                                       $"[Guid(\"{operatorGuid}\")]\n    public class {symbolName}"
                                      );
            
            // insert interop using
            const string usingSystemRuntimeInterOp = "using System.Runtime.InteropServices;";
            if (!newContent.Contains(usingSystemRuntimeInterOp))
            {
                newContent = usingSystemRuntimeInterOp + "\n" + newContent;
            }
                
            Log.Debug($"writing new format {filepath}: {newContent}");
            File.WriteAllText(filepath, newContent);
        }
    }

    private static string _otherOpDirectory = "..\\t3-main\\Operators";
    private static string _warning = "Please select a soundtrack file";
}