using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

namespace AlicizaX.PackageManager.Editor
{
    [EditorWindowTitle(title = "Package Manager", icon = "Package Manager")]
    internal class FrameworkPackageManagerWindow : EditorWindow
    {
        private const string VisualAssetPath = "Packages/com.alicizax.unity.packagemanager/Editor/PackageManager/Res/AlicizaXPackageManagerWindow.uxml";

        public static FrameworkPackageManagerWindow Instance;

        public List<RepositoryPackageData> RepositoryPackageDatas { get; private set; } = new List<RepositoryPackageData>();

        private PackageListView packageListView;
        private PackageInfoView packageInfoView;
        private PackageBottomStateBar bottomStateBar;
        private bool isRefreshing;

        public FrameworkPackageManagerWindow()
        {
            Instance = this;
        }

        [MenuItem("AlicizaX/PackageManager")]
        internal static void Open()
        {
            GetWindow<FrameworkPackageManagerWindow>().Show();
        }

        public void Refresh()
        {
            if (isRefreshing)
            {
                return;
            }

            isRefreshing = true;
            SetRefreshState("Refreshing packages...");

            RepositoryDataFetcher.FetchRepositoryData(datas =>
            {
                RepositoryPackageDatas = datas ?? new List<RepositoryPackageData>();
                PackageManagerCheckTool.RefreshInstalledPackages(_ =>
                {
                    PackageManagerCheckTool.ValidatePackageStates(RepositoryPackageDatas);
                    RebuildList();
                    isRefreshing = false;
                    SetRefreshState($"Last refresh: {RepositoryDataFetcher.GetLastRefreshTime()}");
                });
            });
        }

        public void RefreshPackage(string packageName)
        {
            if (string.IsNullOrEmpty(packageName))
            {
                return;
            }

            var package = RepositoryPackageDatas.FirstOrDefault(t => string.Equals(t.name, packageName, StringComparison.OrdinalIgnoreCase));
            if (package == null)
            {
                return;
            }

            PackageManagerCheckTool.ValidatePackageStates(new List<RepositoryPackageData> { package });

            RebuildList();
            if (packageListView.selectedItem == package)
            {
                packageInfoView.RefreshView(package);
            }
        }

        public bool IsBusy()
        {
            return isRefreshing || PackageOperationRunner.IsBusy;
        }

        private void OnDestroy()
        {
            if (Instance == this)
            {
                Instance = null;
            }

            PackageManagerCoroutines.DestroyCoroutines();
        }

        private void CreateGUI()
        {
            var visualTree = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(VisualAssetPath);
            visualTree?.CloneTree(rootVisualElement);
            CreateLayout();
            Refresh();
        }

        private void CreateLayout()
        {
            var leftContainer = rootVisualElement.Q<VisualElement>("LeftContainer");
            leftContainer.style.backgroundColor = new Color(0.1686275f, 0.1606275f, 0.1686275f);

            packageListView = new PackageListView();
            packageListView.OnSelectionChangedEvent += OnPackageSelectionChanged;
            leftContainer.Add(packageListView);

            bottomStateBar = new PackageBottomStateBar(this);
            leftContainer.Add(bottomStateBar);

            var rightContainer = rootVisualElement.Q<VisualElement>("RightContainer");
            packageInfoView = new PackageInfoView(this);
            rightContainer.Add(packageInfoView);

            packageListView.itemsSource = RepositoryPackageDatas;
        }

        private void RebuildList()
        {
            packageListView.itemsSource = RepositoryPackageDatas;
            packageListView.Rebuild();

            if (RepositoryPackageDatas.Count > 0 && packageListView.selectedIndex < 0)
            {
                packageListView.SetSelection(0);
                packageInfoView.RefreshView(RepositoryPackageDatas[0]);
            }
            else if (packageListView.selectedItem is RepositoryPackageData selected)
            {
                packageInfoView.RefreshView(selected);
            }
            else
            {
                packageInfoView.RefreshView(null);
            }
        }

        private void OnPackageSelectionChanged(IEnumerable<RepositoryPackageData> selectedItems)
        {
            packageInfoView.RefreshView(selectedItems.FirstOrDefault());
        }

        private void SetRefreshState(string text)
        {
            bottomStateBar?.SetStateText(text);
        }
    }
}