#if UNITY_EDITOR
#nullable enable

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

namespace ShrinkSDK.Installer
{
    internal sealed class ShrinkSdkInstallerWindow : EditorWindow
    {
        private readonly Dictionary<string, UnityEditor.PackageManager.PackageInfo> _installed =
            new(StringComparer.Ordinal);
        private ListRequest? _listRequest;
        private bool _resolvePending;
        private double _resolveRequestedAt;
        private bool _listRetryPending;
        private double _nextListRetryAt;
        private int _listRetryCount;
        private HelpBox? _statusBox;
        private Label? _registryState;
        private VisualElement? _page;
        private ToolbarToggle? _bundleTab;
        private ToolbarToggle? _packageTab;
        private string _searchText = string.Empty;
        private bool _showBundles = true;

        [MenuItem("ShrinkSDK/包管理")]
        private static void Open()
        {
            var window = GetWindow<ShrinkSdkInstallerWindow>("ShrinkSDK 包管理");
            window.minSize = new Vector2(820f, 560f);
            window.Show();
        }

        public void CreateGUI()
        {
            var root = rootVisualElement;
            root.Clear();
            root.style.flexDirection = FlexDirection.Column;
            root.Add(BuildHeader());
            root.Add(BuildToolbar());

            _page = new ScrollView(ScrollViewMode.Vertical);
            _page.style.flexGrow = 1f;
            _page.style.paddingLeft = 16f;
            _page.style.paddingRight = 16f;
            _page.style.paddingTop = 12f;
            _page.style.paddingBottom = 16f;
            root.Add(_page);

            _statusBox = new HelpBox("正在读取已安装包……", HelpBoxMessageType.Info);
            _statusBox.style.marginLeft = 16f;
            _statusBox.style.marginRight = 16f;
            _statusBox.style.marginBottom = 12f;
            root.Add(_statusBox);

            RenderPage();
            RefreshPackages();
        }

        private VisualElement BuildHeader()
        {
            var header = new VisualElement();
            header.style.paddingLeft = 16f;
            header.style.paddingRight = 16f;
            header.style.paddingTop = 14f;
            header.style.paddingBottom = 10f;
            header.style.borderBottomWidth = 1f;
            header.style.borderBottomColor = new Color(0.25f, 0.25f, 0.25f);
            header.style.minHeight = 104f;

            var title = new Label("ShrinkSDK 包管理");
            title.style.fontSize = 20f;
            title.style.unityFontStyleAndWeight = FontStyle.Bold;
            title.style.height = 28f;
            title.style.unityTextAlign = TextAnchor.MiddleLeft;
            header.Add(title);

            var description = new Label("以 Context 为组合基础，按用途安装固定版本的模块与集成包。");
            description.style.marginTop = 4f;
            description.style.minHeight = 20f;
            description.style.whiteSpace = WhiteSpace.Normal;
            header.Add(description);

            var registryRow = new VisualElement();
            registryRow.style.flexDirection = FlexDirection.Row;
            registryRow.style.alignItems = Align.Center;
            registryRow.style.marginTop = 10f;
            registryRow.style.minHeight = 22f;
            registryRow.Add(new Label("软件源："));

            _registryState = new Label();
            _registryState.style.flexGrow = 1f;
            _registryState.style.unityFontStyleAndWeight = FontStyle.Bold;
            registryRow.Add(_registryState);

            var configure = new Button(ConfigureRegistry) { text = "配置软件源" };
            configure.style.width = 110f;
            registryRow.Add(configure);
            header.Add(registryRow);

            RefreshRegistryState();
            return header;
        }

        private VisualElement BuildToolbar()
        {
            var toolbar = new Toolbar();
            _bundleTab = new ToolbarToggle { text = "推荐组合", value = true };
            _packageTab = new ToolbarToggle { text = "全部包" };
            _bundleTab.RegisterValueChangedCallback(evt =>
            {
                if (!evt.newValue)
                    return;
                _showBundles = true;
                _packageTab?.SetValueWithoutNotify(false);
                RenderPage();
            });
            _packageTab.RegisterValueChangedCallback(evt =>
            {
                if (!evt.newValue)
                    return;
                _showBundles = false;
                _bundleTab?.SetValueWithoutNotify(false);
                RenderPage();
            });
            toolbar.Add(_bundleTab);
            toolbar.Add(_packageTab);
            toolbar.Add(new ToolbarSpacer { flex = true });

            var search = new ToolbarSearchField();
            search.style.width = 230f;
            search.RegisterValueChangedCallback(evt =>
            {
                _searchText = evt.newValue?.Trim() ?? string.Empty;
                RenderPage();
            });
            toolbar.Add(search);
            toolbar.Add(new ToolbarButton(RefreshPackages) { text = "刷新状态" });
            return toolbar;
        }

        private void RenderPage()
        {
            if (_page == null)
                return;
            _page.Clear();
            if (_showBundles)
                RenderBundles(_page);
            else
                RenderPackages(_page);
        }

        private void RenderBundles(VisualElement parent)
        {
            foreach (var bundle in ShrinkSdkPackageCatalog.Bundles.Where(MatchesSearch))
            {
                var card = CreateCard();
                var titleRow = new VisualElement();
                titleRow.style.flexDirection = FlexDirection.Row;
                titleRow.style.alignItems = Align.Center;
                var title = new Label(bundle.DisplayName + (bundle.Recommended ? "  ·  推荐" : string.Empty));
                title.style.fontSize = 15f;
                title.style.unityFontStyleAndWeight = FontStyle.Bold;
                title.style.flexGrow = 1f;
                titleRow.Add(title);

                var ready = bundle.Packages.Count(IsInstalledAtLeast);
                var button = new Button(() => BeginInstall(bundle.InstallRoots));
                if (ready == bundle.Packages.Count)
                {
                    button.text = "已完成";
                    button.SetEnabled(false);
                }
                else
                {
                    button.text = ready > 0 ? "补齐组合" : "安装组合";
                    button.SetEnabled(!IsBusy);
                }
                button.style.width = 100f;
                titleRow.Add(button);
                card.Add(titleRow);

                var summary = new Label(bundle.Summary);
                summary.style.whiteSpace = WhiteSpace.Normal;
                summary.style.marginTop = 5f;
                card.Add(summary);

                var progress = new Label($"已就绪 {ready}/{bundle.Packages.Count}");
                progress.style.marginTop = 8f;
                progress.style.color = ready == bundle.Packages.Count
                    ? new Color(0.35f, 0.75f, 0.45f)
                    : new Color(0.65f, 0.65f, 0.65f);
                card.Add(progress);

                var contents = new Foldout { text = "包含的包", value = false };
                contents.style.marginTop = 4f;
                foreach (var package in bundle.Packages)
                    contents.Add(CreateCompactPackageRow(package));
                card.Add(contents);
                parent.Add(card);
            }
        }

        private void RenderPackages(VisualElement parent)
        {
            var packages = ShrinkSdkPackageCatalog.Packages.Where(MatchesSearch).ToArray();
            foreach (var group in packages.GroupBy(entry => entry.Layer))
            {
                var heading = new Label(GetLayerName(group.Key));
                heading.style.fontSize = 15f;
                heading.style.unityFontStyleAndWeight = FontStyle.Bold;
                heading.style.marginTop = 8f;
                heading.style.marginBottom = 4f;
                parent.Add(heading);
                foreach (var package in group)
                    parent.Add(CreatePackageCard(package));
            }
        }

        private VisualElement CreatePackageCard(ShrinkSdkPackageEntry package)
        {
            var card = CreateCard();
            var row = new VisualElement();
            row.style.flexDirection = FlexDirection.Row;
            row.style.alignItems = Align.Center;
            var text = new VisualElement();
            text.style.flexGrow = 1f;
            var title = new Label(package.DisplayName);
            title.style.unityFontStyleAndWeight = FontStyle.Bold;
            text.Add(title);
            var id = new Label(package.PackageName + "  ·  固定版本 " + package.Version);
            id.style.fontSize = 10f;
            id.style.color = new Color(0.58f, 0.58f, 0.58f);
            id.style.marginTop = 2f;
            text.Add(id);
            var summary = new Label(package.Summary);
            summary.style.whiteSpace = WhiteSpace.Normal;
            summary.style.marginTop = 4f;
            text.Add(summary);
            row.Add(text);

            var action = CreatePackageAction(package);
            action.style.width = 118f;
            action.style.marginLeft = 12f;
            row.Add(action);
            card.Add(row);
            return card;
        }

        private VisualElement CreateCompactPackageRow(ShrinkSdkPackageEntry package)
        {
            var row = new VisualElement();
            row.style.flexDirection = FlexDirection.Row;
            row.style.alignItems = Align.Center;
            row.style.marginTop = 3f;
            var name = new Label(package.DisplayName);
            name.style.flexGrow = 1f;
            row.Add(name);
            var status = new Label(GetInstalledStatus(package));
            status.style.fontSize = 10f;
            status.style.color = IsInstalledAtLeast(package)
                ? new Color(0.35f, 0.75f, 0.45f)
                : new Color(0.65f, 0.65f, 0.65f);
            row.Add(status);
            return row;
        }

        private Button CreatePackageAction(ShrinkSdkPackageEntry package)
        {
            var button = new Button(() => BeginInstall(new[] { package }));
            if (!_installed.TryGetValue(package.PackageName, out var installed))
                button.text = "安装 " + package.Version;
            else
            {
                switch (ShrinkPackageVersion.Classify(installed.version, package.Version))
                {
                    case ShrinkPackageVersionRelation.Equal:
                        button.text = "已安装 " + installed.version;
                        button.SetEnabled(false);
                        break;
                    case ShrinkPackageVersionRelation.Newer:
                        button.text = "较新版本 " + installed.version;
                        button.SetEnabled(false);
                        break;
                    case ShrinkPackageVersionRelation.Older:
                        button.text = "升级 " + installed.version + " → " + package.Version;
                        break;
                    default:
                        button.text = installed.version + " → " + package.Version;
                        break;
                }
            }

            if (IsBusy)
                button.SetEnabled(false);
            return button;
        }

        private static VisualElement CreateCard()
        {
            var card = new VisualElement();
            card.style.marginBottom = 8f;
            card.style.paddingLeft = 12f;
            card.style.paddingRight = 12f;
            card.style.paddingTop = 10f;
            card.style.paddingBottom = 10f;
            card.style.borderLeftWidth = 1f;
            card.style.borderRightWidth = 1f;
            card.style.borderTopWidth = 1f;
            card.style.borderBottomWidth = 1f;
            card.style.borderLeftColor = new Color(0.28f, 0.28f, 0.28f);
            card.style.borderRightColor = new Color(0.28f, 0.28f, 0.28f);
            card.style.borderTopColor = new Color(0.28f, 0.28f, 0.28f);
            card.style.borderBottomColor = new Color(0.28f, 0.28f, 0.28f);
            card.style.borderTopLeftRadius = 4f;
            card.style.borderTopRightRadius = 4f;
            card.style.borderBottomLeftRadius = 4f;
            card.style.borderBottomRightRadius = 4f;
            return card;
        }

        private bool MatchesSearch(ShrinkSdkPackageBundle bundle) =>
            string.IsNullOrEmpty(_searchText) ||
            bundle.DisplayName.IndexOf(_searchText, StringComparison.OrdinalIgnoreCase) >= 0 ||
            bundle.Summary.IndexOf(_searchText, StringComparison.OrdinalIgnoreCase) >= 0 ||
            bundle.Packages.Any(MatchesSearch);

        private bool MatchesSearch(ShrinkSdkPackageEntry package) =>
            string.IsNullOrEmpty(_searchText) ||
            package.DisplayName.IndexOf(_searchText, StringComparison.OrdinalIgnoreCase) >= 0 ||
            package.Summary.IndexOf(_searchText, StringComparison.OrdinalIgnoreCase) >= 0 ||
            package.PackageName.IndexOf(_searchText, StringComparison.OrdinalIgnoreCase) >= 0;

        private bool IsInstalledAtLeast(ShrinkSdkPackageEntry package) =>
            _installed.TryGetValue(package.PackageName, out var installed) &&
            ShrinkPackageVersion.Classify(installed.version, package.Version) is
                ShrinkPackageVersionRelation.Equal or ShrinkPackageVersionRelation.Newer;

        private string GetInstalledStatus(ShrinkSdkPackageEntry package)
        {
            if (!_installed.TryGetValue(package.PackageName, out var installed))
                return "未安装 · " + package.Version;
            return ShrinkPackageVersion.Classify(installed.version, package.Version) switch
            {
                ShrinkPackageVersionRelation.Equal => "已安装 " + installed.version,
                ShrinkPackageVersionRelation.Newer => "已安装较新版本 " + installed.version,
                ShrinkPackageVersionRelation.Older => "可升级 " + installed.version + " → " + package.Version,
                _ => "已安装 " + installed.version + " · 目标 " + package.Version
            };
        }

        private bool IsBusy => _listRequest != null || _resolvePending || _listRetryPending;

        private void Update()
        {
            if (_resolvePending && EditorApplication.timeSinceStartup - _resolveRequestedAt >= 0.5d)
            {
                _resolvePending = false;
                SetStatus("正在等待依赖解析并刷新安装状态。", HelpBoxMessageType.Info);
                StartListRequest();
            }

            if (_listRetryPending && EditorApplication.timeSinceStartup >= _nextListRetryAt)
            {
                _listRetryPending = false;
                StartListRequest();
            }

            if (_listRequest == null || !_listRequest.IsCompleted)
                return;

            var list = _listRequest;
            _listRequest = null;
            if (list.Status == StatusCode.Success)
            {
                _listRetryCount = 0;
                _installed.Clear();
                foreach (var package in list.Result)
                    _installed[package.name] = package;
                var count = _installed.Keys.Count(name => name.StartsWith("com.cneicy.", StringComparison.Ordinal));
                SetStatus("状态已刷新：当前项目共解析到 " + count + " 个 ShrinkSDK 包。", HelpBoxMessageType.Info);
            }
            else if (string.IsNullOrWhiteSpace(list.Error?.message) && _listRetryCount < 4)
            {
                _listRetryCount++;
                _listRetryPending = true;
                _nextListRetryAt = EditorApplication.timeSinceStartup + 1d;
                SetStatus("Unity 正在完成依赖解析，稍后自动重试安装状态（" + _listRetryCount + "/4）。",
                    HelpBoxMessageType.Info);
            }
            else
            {
                SetStatus("读取安装状态失败：" + GetRequestError(list.Error), HelpBoxMessageType.Warning);
            }
            RenderPage();
        }

        private void ConfigureRegistry()
        {
            if (IsBusy)
                return;
            try
            {
                ShrinkSdkManifestStore.EnsureShrinkSdkRegistry();
                RefreshRegistryState();
                BeginResolve("软件源已写入，Unity 正在解析依赖。");
            }
            catch (Exception exception)
            {
                SetStatus(exception.Message, HelpBoxMessageType.Error);
            }
        }

        private void BeginInstall(IEnumerable<ShrinkSdkPackageEntry> packages)
        {
            if (IsBusy)
                return;
            try
            {
                var roots = ShrinkSdkPackageCatalog.DistinctInstallRoots(packages);
                ShrinkSdkManifestStore.EnsurePackageInstallation(roots);
                RefreshRegistryState();
                BeginResolve("已写入 " + roots.Count + " 个固定版本入口，Unity 正在安装并解析依赖。");
            }
            catch (Exception exception)
            {
                SetStatus(exception.Message, HelpBoxMessageType.Error);
            }
        }

        private void BeginResolve(string status)
        {
            _listRequest = null;
            Client.Resolve();
            _listRetryPending = false;
            _listRetryCount = 0;
            _resolvePending = true;
            _resolveRequestedAt = EditorApplication.timeSinceStartup;
            SetStatus(status, HelpBoxMessageType.Info);
            RenderPage();
        }

        private void RefreshPackages()
        {
            if (IsBusy)
                return;
            _listRetryCount = 0;
            StartListRequest();
            SetStatus("正在读取当前项目的直接与间接依赖。", HelpBoxMessageType.Info);
            RenderPage();
        }

        private void StartListRequest()
        {
            if (_listRequest == null)
                _listRequest = Client.List(true, true);
        }

        private void RefreshRegistryState()
        {
            if (_registryState == null)
                return;
            try
            {
                var configured = ShrinkSdkManifestStore.HasShrinkSdkRegistry();
                _registryState.text = configured ? "已配置 · " + ShrinkSdkPackageCatalog.RegistryUrl : "未配置";
                _registryState.style.color = configured
                    ? new Color(0.35f, 0.75f, 0.45f)
                    : new Color(0.85f, 0.55f, 0.25f);
            }
            catch (Exception exception)
            {
                _registryState.text = "无法读取 Packages/manifest.json";
                _registryState.style.color = new Color(0.85f, 0.35f, 0.3f);
                SetStatus(exception.Message, HelpBoxMessageType.Error);
            }
        }

        private void SetStatus(string message, HelpBoxMessageType type)
        {
            if (_statusBox == null)
                return;
            _statusBox.text = message;
            _statusBox.messageType = type;
        }

        private static string GetRequestError(Error? error)
        {
            var message = error?.message;
            return string.IsNullOrWhiteSpace(message)
                ? "Unity Package Manager 未返回详细原因，请在依赖解析结束后刷新状态。"
                : message!;
        }

        private static string GetLayerName(ShrinkSdkPackageLayer layer) => layer switch
        {
            ShrinkSdkPackageLayer.Context => "Context 组合基础",
            ShrinkSdkPackageLayer.Host => "应用与组合根",
            ShrinkSdkPackageLayer.Feature => "独立功能模块",
            ShrinkSdkPackageLayer.Integration => "模块集成",
            ShrinkSdkPackageLayer.Tooling => "编译与工具基础",
            _ => layer.ToString()
        };
    }
}
#endif