// Copyright (c) 2025 TerraByte Inc.
//
// A new, non-dockable editor window for viewing and managing changes
// stored in the 'Better Git Stash'.

using System;
using UnityEditor;
using UnityEngine;
using UnityEngine.Scripting;
using Terra.Arbitrator.Services;
using System.Collections.Generic;

namespace Terra.Arbitrator.GUI
{
    [Preserve]
    public class StashedChangesWindow : EditorWindow
    {
        private ArbitratorController _controller;
        private List<GitChange> _stashedFiles;
        private Vector2 _scrollPosition;
        private Action _onClose;

        public static void ShowWindow(ArbitratorController controller, List<GitChange> stashedFiles, Action onClose = null)
        {
            var window = GetWindow<StashedChangesWindow>(true, "Stashed Changes", true);
            window.minSize = new Vector2(500, 350);
            window._controller = controller;
            window._stashedFiles = stashedFiles;
            window._onClose = onClose;
            window.ShowUtility();
        }

        private void OnGUI()
        {
            if (_controller == null || _stashedFiles == null)
            {
                EditorGUILayout.LabelField("No data available.");
                return;
            }
            
            DrawHeader();
            DrawFileList();
            DrawFooter();
        }

        private void DrawHeader()
        {
            EditorGUILayout.LabelField("Files in 'Better Git Stash'", EditorStyles.boldLabel);
            EditorGUILayout.BeginHorizontal();

            if (GUILayout.Button("Apply Stash", GUILayout.Height(30)))
            {
                _controller.ApplyStash();
                Close();
            }

            if (GUILayout.Button("Discard Stash", GUILayout.Height(30)))
            {
                if (EditorUtility.DisplayDialog("Discard Stash?", "Are you sure you want to discard the 'Better Git Stash'? This action cannot be undone.", "Yes, Discard", "Cancel"))
                {
                    _controller.DiscardStash();
                    Close();
                }
            }

            EditorGUILayout.EndHorizontal();
            EditorGUILayout.Space();
        }

        private void DrawFileList()
        {
            _scrollPosition = EditorGUILayout.BeginScrollView(_scrollPosition, EditorStyles.helpBox);

            foreach (var change in _stashedFiles)
            {
                EditorGUILayout.BeginHorizontal(EditorStyles.helpBox);
                
                string status;
                Color statusColor;

                switch (change.Status)
                {
                    case LibGit2Sharp.ChangeKind.Added:
                        status = "[+]";
                        statusColor = Color.green;
                        break;
                    case LibGit2Sharp.ChangeKind.Deleted:
                        status = "[-]";
                        statusColor = Color.red;
                        break;
                    case LibGit2Sharp.ChangeKind.Modified:
                        status = "[M]";
                        statusColor = new Color(1.0f, 0.6f, 0.0f);
                        break;
                    case LibGit2Sharp.ChangeKind.Renamed:
                        status = "[R]";
                        statusColor = new Color(0.6f, 0.6f, 1.0f);
                        break;
                    default:
                        status = "[?]";
                        statusColor = Color.white;
                        break;
                }

                var originalColor = UnityEngine.GUI.color;
                UnityEngine.GUI.color = statusColor;
                EditorGUILayout.LabelField(new GUIContent(status, change.Status.ToString()), GUILayout.Width(25));
                UnityEngine.GUI.color = originalColor;
                
                var filePathDisplay = change.Status == LibGit2Sharp.ChangeKind.Renamed
                    ? $"{change.OldFilePath} -> {change.FilePath}"
                    : change.FilePath;

                EditorGUILayout.LabelField(new GUIContent(filePathDisplay, filePathDisplay));

                if (GUILayout.Button("Diff", GUILayout.Width(60)))
                {
                    _controller.DiffStashedFile(change);
                }
                
                EditorGUILayout.EndHorizontal();
            }

            EditorGUILayout.EndScrollView();
        }

        private void DrawFooter()
        {
            GUILayout.FlexibleSpace();
            EditorGUILayout.BeginHorizontal();
            GUILayout.FlexibleSpace();
            if (GUILayout.Button("Close", GUILayout.Width(100)))
            {
                Close();
            }
            EditorGUILayout.EndHorizontal();
            EditorGUILayout.Space();
        }
        
        private void OnDestroy()
        {
            _onClose?.Invoke();
        }
    }
}