// Copyright (c) 2025 TerraByte Inc.
//
// A modal editor window that displays pull conflicts and allows the user
// to select files to reset before proceeding.

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

namespace Terra.Arbitrator.GUI
{
    [Preserve]
    public class ConflictResolutionWindow : EditorWindow
    {
        private Vector2 _scrollPosition;
        private GUIStyle _wordWrapStyle;
        private IConflictSource _conflictSource;
        private ArbitratorController _controller;
        private List<GitChange> _conflictingFiles;

        /// <summary>
        /// Shows a modal window to display pull conflicts and get user action.
        /// </summary>
        /// <param name="controller">Reference to the arbitrator controller</param>
        /// <param name="conflictingFiles">The list of files that have conflicts.</param>
        /// <param name="source">The source of the conflict (e.g., pull, stash).</param>
        public static void ShowWindow(ArbitratorController controller, IReadOnlyList<GitChange> conflictingFiles, IConflictSource source)
        {
            var window = GetWindow<ConflictResolutionWindow>(true, "Pull Conflicts Detected", true);
            window.minSize = new Vector2(600, 400);
            window._controller = controller;
            window._conflictingFiles = new List<GitChange>(conflictingFiles);
            window._conflictSource = source;
            window.ShowModalUtility();
        }

        private void OnGUI()
        {
            _wordWrapStyle ??= new GUIStyle(EditorStyles.label) { wordWrap = true };
            
            EditorGUILayout.HelpBox("A pull would result in conflicts with your local changes. To proceed with a clean pull, you must choose a resolution for the conflicting files listed below.", MessageType.Warning);
            EditorGUILayout.LabelField($"Mine: {_conflictSource?.MineLabel ?? "Your Changes"}", EditorStyles.boldLabel);
            EditorGUILayout.LabelField($"Theirs: {_conflictSource?.TheirsLabel ?? "Incoming Changes"}", EditorStyles.boldLabel);
            
            EditorGUILayout.BeginHorizontal(EditorStyles.toolbar);
            GUILayout.Label("Filename");
            GUILayout.FlexibleSpace();
            GUILayout.Label(""); //Spacer
            GUILayout.FlexibleSpace();
            GUILayout.Label("Choice", GUILayout.Width(70));
            EditorGUILayout.EndHorizontal();

            _scrollPosition = EditorGUILayout.BeginScrollView(_scrollPosition, EditorStyles.helpBox);
            if (_conflictingFiles != null)
            {
                foreach (var change in _conflictingFiles)
                {
                    DrawFileRow(change);
                }
            }
            EditorGUILayout.EndScrollView();

            EditorGUILayout.Space();
            DrawActionButtons();
        }
        
        private void DrawFileRow(GitChange change)
        {
            EditorGUILayout.BeginHorizontal(EditorStyles.helpBox);

            EditorGUILayout.LabelField(new GUIContent(change.FilePath, change.FilePath), _wordWrapStyle, GUILayout.ExpandWidth(true));
            change.Resolution = (GitChange.ConflictResolution)EditorGUILayout.EnumPopup(change.Resolution, GUILayout.Width(70));
            
            EditorGUILayout.EndHorizontal();
        }

        private void DrawActionButtons()
        {
            EditorGUILayout.BeginHorizontal();
            GUILayout.FlexibleSpace();

            var allResolved = _conflictingFiles != null && _conflictingFiles.All(c => c.Resolution != GitChange.ConflictResolution.None);
            var pullButtonText = allResolved ? "Resolve Safely" : "Resolve with Unchosen (Risky)";

            if (GUILayout.Button(pullButtonText, GUILayout.Height(30), GUILayout.Width(180)))
            {
                if (_controller != null && _conflictSource != null)
                {
                    _controller.ResolveConflicts(_conflictingFiles, _conflictSource);
                }
                Close();
            }
            if (GUILayout.Button("Cancel", GUILayout.Height(30)))
            {
                Close();
            }
            
            EditorGUILayout.EndHorizontal();
        }
    }
}