#nullable enable

using System;
using System.Collections.Generic;
using System.Linq;
using Cysharp.Threading.Tasks;
using Demo2.Domain;
using Demo2.ECS;
using ShrinkTutorial;
using TMPro;
using Unity.Entities;
using UnityEngine;
using UnityEngine.UIElements;

namespace Demo2.Runtime
{
    public sealed class Demo2DemoController : MonoBehaviour
    {
        private enum ScreenKind { Title, Lobby, Factory, Reward, End }

        [SerializeField] private Camera? worldCamera;
        [SerializeField] private Demo2MachineProxyPool? proxyPool;
        [SerializeField] private Demo2ItemBatchRenderer? itemBatchRenderer;
        [SerializeField] private UIDocument? uiDocument;
        [SerializeField] private StyleSheet? uiStyleSheet;
        [SerializeField] private Sprite? titleBackground;
        [SerializeField] private Sprite[] machineIcons = Array.Empty<Sprite>();
        [SerializeField] private Font? uiFont;
        [SerializeField] private TMP_FontAsset? tutorialFont;
        [SerializeField] private RectTransform? tutorialAnchorRoot;

        private readonly Dictionary<ScreenKind, VisualElement> _screens = new();
        private readonly Dictionary<string, RectTransform> _tutorialAnchors = new(StringComparer.Ordinal);
        private Demo2GameService? _service;
        private Demo2LanRuntime? _lan;
        private Demo2GridInput? _gridInput;
        private VisualElement? _root;
        private ScreenKind _screen;
        private Demo2MachineKind _selectedKind = Demo2MachineKind.Conveyor;
        private byte _rotation;
        private bool _removeMode;
        private Demo2TransportMode _transportMode = Demo2TransportMode.Tcp;
        private bool _dirty = true;
        private bool _uiReady;
        private float _visualTimer;
        private long _networkBuildSequence;
        private int _selectedRecipeId;

        private static readonly (string anchorId, string elementName)[] TutorialTargets =
        {
            ("demo2.miner", "miner-button"),
            ("demo2.conveyor", "conveyor-button"),
            ("demo2.grid", "grid-input-surface"),
            ("demo2.smelter", "smelter-button"),
            ("demo2.recipe", "recipe-button"),
            ("demo2.turret", "turret-button"),
            ("demo2.ready", "ready-button"),
            ("demo2.reward", "reward-choose-1")
        };

        private void Awake()
        {
            if (Application.isBatchMode || Array.IndexOf(Environment.GetCommandLineArgs(), "-demo2-headless") >= 0)
            {
                enabled = false;
                return;
            }
            _service = Demo2GameService.Current ?? new Demo2GameService();
            _lan = new Demo2LanRuntime(_service);
            if (tutorialFont != null && !TMP_Settings.fallbackFontAssets.Contains(tutorialFont)) TMP_Settings.fallbackFontAssets.Add(tutorialFont);
            var tutorialSettings = Resources.Load<ShrinkTutorialSettings>("Demo2TutorialSettings");
            if (tutorialSettings != null) ShrinkTutorialManager.EnsureInstance(tutorialSettings);
            _service.Changed += MarkDirty;
            _lan.Changed += MarkDirty;
        }

        private void Start()
        {
            if (uiDocument == null) throw new InvalidOperationException("Demo2 UIDocument is not assigned.");
            _root = uiDocument.rootVisualElement;
            if (uiStyleSheet != null && !_root.styleSheets.Contains(uiStyleSheet)) _root.styleSheets.Add(uiStyleSheet);
            if (uiFont != null) _root.style.unityFont = uiFont;
            CacheScreens();
            CacheTutorialAnchors();
            ApplyArt();
            BindTitle();
            BindLobby();
            BindFactory();
            BindReward();
            BindEnd();
            if (worldCamera == null) throw new InvalidOperationException("Demo2 WorldCamera is not assigned.");
            _gridInput = new Demo2GridInput(Require<VisualElement>("grid-input-surface"), worldCamera);
            _gridInput.GridClicked += OnGridClicked;
            _root.RegisterCallback<GeometryChangedEvent>(_ =>
            {
                ApplySafeArea();
                SyncTutorialAnchors();
            });
            _uiReady = true;
            Show(ScreenKind.Title);
            _root.schedule.Execute(ApplySafeArea).ExecuteLater(1);
        }

        private void Update()
        {
            if (!_uiReady) return;
            _lan?.Pump();
            if (_screen == ScreenKind.Factory && ShrinkTutorialManager.Instance?.IsRunning != true) _service?.AdvanceFrame(Time.unscaledDeltaTime);
            RoutePhaseScreen();
            _visualTimer -= Time.unscaledDeltaTime;
            if (_visualTimer <= 0)
            {
                _visualTimer = 0.1f;
                proxyPool?.Refresh(_service?.EcsWorld);
                itemBatchRenderer?.Bind(_service?.EcsWorld);
                _dirty = true;
            }
            if (_dirty) Refresh();
        }

        private void OnDestroy()
        {
            if (_service != null) _service.Changed -= MarkDirty;
            if (_lan != null) _lan.Changed -= MarkDirty;
            if (_gridInput != null)
            {
                _gridInput.GridClicked -= OnGridClicked;
                _gridInput.Dispose();
            }
            _lan?.Dispose();
        }

        private void CacheScreens()
        {
            _screens[ScreenKind.Title] = Require<VisualElement>("title-screen");
            _screens[ScreenKind.Lobby] = Require<VisualElement>("lobby-screen");
            _screens[ScreenKind.Factory] = Require<VisualElement>("factory-screen");
            _screens[ScreenKind.Reward] = Require<VisualElement>("reward-screen");
            _screens[ScreenKind.End] = Require<VisualElement>("end-screen");
        }

        private void CacheTutorialAnchors()
        {
            if (tutorialAnchorRoot == null) return;
            foreach (var target in TutorialTargets)
            {
                var child = tutorialAnchorRoot.Find(target.anchorId);
                if (child is RectTransform rect) _tutorialAnchors[target.anchorId] = rect;
            }
        }

        private void ApplyArt()
        {
            if (titleBackground != null) Require<VisualElement>("title-background").style.backgroundImage = new StyleBackground(titleBackground);
            var names = new[] { "miner", "conveyor", "splitter", "smelter", "assembler", "loader", "turret", "generator" };
            for (var i = 0; i < names.Length && i < machineIcons.Length; i++)
                if (machineIcons[i] != null) Require<VisualElement>(names[i] + "-icon").style.backgroundImage = new StyleBackground(machineIcons[i]);
        }

        private void BindTitle()
        {
            Bind("solo-button", StartSolo);
            Bind("host-button", HostLan);
            Bind("join-button", JoinLan);
            Bind("transport-button", ToggleTransport);
        }

        private void BindLobby()
        {
            Bind("lobby-back-button", LeaveLobby);
            Bind("lobby-ready-button", () => _lan?.SetReady(true));
            Bind("lobby-start-button", StartHostedMatch);
        }

        private void BindFactory()
        {
            var pairs = new[]
            {
                (Demo2MachineKind.Miner, "miner-button"),
                (Demo2MachineKind.Conveyor, "conveyor-button"),
                (Demo2MachineKind.Splitter, "splitter-button"),
                (Demo2MachineKind.Smelter, "smelter-button"),
                (Demo2MachineKind.Assembler, "assembler-button"),
                (Demo2MachineKind.Loader, "loader-button"),
                (Demo2MachineKind.Turret, "turret-button"),
                (Demo2MachineKind.Generator, "generator-button")
            };
            foreach (var pair in pairs)
            {
                var local = pair.Item1;
                Bind(pair.Item2, () => SelectMachine(local));
            }
            Bind("rotate-button", () => { _rotation = (byte)((_rotation + 1) & 3); _dirty = true; });
            Bind("remove-button", () => { _removeMode = !_removeMode; _dirty = true; });
            Bind("ready-button", ReadyForProduction);
            Bind("speed-1-button", () => _service?.SetSpeed(1));
            Bind("speed-4-button", () => _service?.SetSpeed(4));
            Bind("speed-10-button", () => _service?.SetSpeed(10));
            Bind("save-button", () => _service?.SaveAsync().Forget(LogException));
            Bind("load-button", () => _service?.LoadAsync().Forget(LogException));
            Bind("exit-button", ExitToTitle);
            Bind("recipe-button", ConfirmRecipe);
            Bind("rule-up-1", () => _service?.ReorderRule(0, 0));
            Bind("rule-up-2", () => _service?.ReorderRule(1, 0));
            Bind("rule-up-3", () => _service?.ReorderRule(2, 1));
            Bind("rule-up-4", () => _service?.ReorderRule(3, 2));
            Bind("rule-up-5", () => _service?.ReorderRule(4, 3));
        }

        private void BindReward()
        {
            Bind("reward-choose-1", () => ChooseReward(0));
            Bind("reward-choose-2", () => ChooseReward(1));
            Bind("reward-choose-3", () => ChooseReward(2));
        }

        private void BindEnd()
        {
            Bind("restart-button", StartSolo);
            Bind("title-button", ExitToTitle);
        }

        private void StartSolo()
        {
            _lan?.Stop();
            _service?.StartNewGame();
            Show(ScreenKind.Factory);
            ShrinkTutorialManager.Instance?.StartTutorial("demo2.first-cycle");
        }

        private void HostLan()
        {
            _service?.StartNewGame();
            _lan?.Host(27320, _transportMode, "host");
            Show(ScreenKind.Lobby);
        }

        private void JoinLan()
        {
            var value = Require<TextField>("direct-ip-input").value;
            var host = string.IsNullOrWhiteSpace(value) ? "127.0.0.1" : value.Trim();
            _service?.StartNewGame(20260817);
            _lan?.Join(host, 27320, _transportMode, "client");
            Show(ScreenKind.Lobby);
        }

        private void StartHostedMatch()
        {
            if (_lan?.IsHost == true) Show(ScreenKind.Factory);
        }

        private void LeaveLobby()
        {
            _lan?.Stop();
            Show(ScreenKind.Title);
        }

        private void ExitToTitle()
        {
            _lan?.Stop();
            Show(ScreenKind.Title);
        }

        private void ToggleTransport()
        {
            _transportMode = _transportMode == Demo2TransportMode.Tcp ? Demo2TransportMode.Kcp : Demo2TransportMode.Tcp;
            _dirty = true;
        }

        private void SelectMachine(Demo2MachineKind kind)
        {
            _selectedKind = kind;
            _selectedRecipeId = _service != null && _service.Content.Machines.TryGetValue(kind, out var machine) ? machine.RecipeId : 0;
            _removeMode = false;
            _dirty = true;
            if (kind == Demo2MachineKind.Miner) ShrinkTutorialManager.Instance?.CompleteStep("demo2.miner-selected");
            if (kind == Demo2MachineKind.Conveyor) ShrinkTutorialManager.Instance?.CompleteStep("demo2.conveyor-selected");
            if (kind == Demo2MachineKind.Smelter) ShrinkTutorialManager.Instance?.CompleteStep("demo2.smelter-selected");
            if (kind == Demo2MachineKind.Turret) ShrinkTutorialManager.Instance?.CompleteStep("demo2.turret-selected");
        }

        private void ConfirmRecipe()
        {
            if (_service != null && _selectedRecipeId == 0 && _service.Content.Recipes.Count > 0)
                _selectedRecipeId = _service.Content.Recipes.Keys.OrderBy(value => value).First();
            ShrinkTutorialManager.Instance?.CompleteStep("demo2.recipe-selected");
            _dirty = true;
        }

        private void ReadyForProduction()
        {
            if (_service == null) return;
            if (_lan?.IsConnected == true) _lan.SetReady(true);
            else _service.SetReady("local", true);
            ShrinkTutorialManager.Instance?.CompleteStep("demo2.production-started");
        }

        private void OnGridClicked(int x, int y, int button)
        {
            if (_service == null || _service.Phase != Demo2Phase.Build) return;
            var remove = _removeMode || button == 1;
            var command = new Demo2BuildCommand
            {
                Sequence = ++_networkBuildSequence,
                IdempotencyToken = (_lan?.LocalPlayerId ?? "local") + "-" + _networkBuildSequence,
                PlayerId = _lan?.LocalPlayerId ?? "local",
                Kind = _selectedKind,
                X = x,
                Y = y,
                Rotation = _rotation,
                RecipeId = _selectedRecipeId,
                Remove = remove
            };
            if (_lan?.IsConnected == true) _lan.SendBuild(command);
            else
            {
                var result = _service.SubmitBuild(command);
                if (result.Accepted && !remove)
                {
                    if (_selectedKind == Demo2MachineKind.Miner) ShrinkTutorialManager.Instance?.CompleteStep("demo2.miner-placed");
                    if (_selectedKind == Demo2MachineKind.Conveyor) ShrinkTutorialManager.Instance?.CompleteStep("demo2.conveyor-placed");
                    if (_selectedKind == Demo2MachineKind.Turret) ShrinkTutorialManager.Instance?.CompleteStep("demo2.turret-placed");
                }
            }
        }

        private void ChooseReward(int index)
        {
            if (_service == null || index < 0 || index >= _service.RewardChoices.Count) return;
            var ruleId = _service.RewardChoices[index];
            if (_lan?.IsConnected == true) _lan.ChooseReward(ruleId, -1);
            else if (_service.ChooseReward(ruleId)) ShrinkTutorialManager.Instance?.CompleteStep("demo2.rule-chosen");
        }

        private void RoutePhaseScreen()
        {
            if (_service == null || _screen is ScreenKind.Title or ScreenKind.Lobby) return;
            if (_service.Phase == Demo2Phase.Reward && _screen != ScreenKind.Reward) Show(ScreenKind.Reward);
            else if (_service.Phase is Demo2Phase.Victory or Demo2Phase.Defeat && _screen != ScreenKind.End) Show(ScreenKind.End);
            else if (_service.Phase is Demo2Phase.Build or Demo2Phase.Production or Demo2Phase.Defense && _screen != ScreenKind.Factory) Show(ScreenKind.Factory);
        }

        private void Show(ScreenKind screen)
        {
            _screen = screen;
            foreach (var pair in _screens) pair.Value.style.display = pair.Key == screen ? DisplayStyle.Flex : DisplayStyle.None;
            if (worldCamera != null) worldCamera.gameObject.SetActive(screen == ScreenKind.Factory);
            if (proxyPool != null) proxyPool.gameObject.SetActive(screen == ScreenKind.Factory);
            if (itemBatchRenderer != null) itemBatchRenderer.gameObject.SetActive(screen == ScreenKind.Factory);
            _dirty = true;
            _root?.schedule.Execute(SyncTutorialAnchors).ExecuteLater(1);
        }

        private void Refresh()
        {
            _dirty = false;
            SetText("transport-button", "传输：" + _transportMode.ToString().ToUpperInvariant());
            if (_service == null) return;
            SetText("lobby-status", _lan?.Status ?? "offline");
            SetText("lobby-players", BuildPlayerList());
            Require<Button>("lobby-start-button").SetEnabled(_lan?.IsHost == true);

            if (_service.EcsWorld != null)
            {
                var manager = _service.EcsWorld.EntityManager;
                var economy = manager.GetComponentData<Demo2EconomyState>(_service.EcsWorld.Singleton);
                var core = manager.GetComponentData<Demo2CoreHealth>(_service.EcsWorld.Singleton);
                SetText("core-text", "核心 " + new string('◆', Math.Max(0, core.Value)));
                SetText("money-text", "资金 " + SaturatingMath.Format(economy.Money));
                SetText("phase-text", $"周期 {_service.Cycle}/5 · {PhaseName(_service.Phase)}");
                SetText("timer-text", TimeSpan.FromSeconds(_service.PhaseRemainingSeconds).ToString(@"mm\:ss"));
                SetText("target-text", $"目标火力  {SaturatingMath.Format(_service.Content.Waves[Math.Max(0, _service.Cycle - 1)].TotalHealth)}\n载荷 × 倍率\n{SaturatingMath.Format(economy.Payload)} × {economy.MultiplierMilli / 1000f:0.00}");
            }
            SetText("selection-text", (_removeMode ? "拆除模式" : "建造 " + MachineName(_selectedKind)) + $" · 朝向 {_rotation * 90}°");
            SetText("error-text", _service.LastError);
            SetText("network-text", _lan?.Status ?? "单人本地");
            var recipeName = _service.Content.Recipes.TryGetValue(_selectedRecipeId, out var recipe) ? recipe.Name : "无";
            SetText("recipe-button", "配方：" + recipeName);
            RefreshMachineSelection();
            RefreshRules();
            RefreshRewards();
            SetText("end-title", _service.Phase == Demo2Phase.Victory ? "工厂守住了核心" : "核心防线失守");
            SetText("end-summary", $"最终周期 {_service.Cycle}/5\n火力 {SaturatingMath.Format(_service.LastFirepower)} / 敌军 {SaturatingMath.Format(_service.LastEnemyHealth)}");
        }

        private void RefreshMachineSelection()
        {
            var names = new[] { "miner", "conveyor", "splitter", "smelter", "assembler", "loader", "turret", "generator" };
            var kinds = new[] { Demo2MachineKind.Miner, Demo2MachineKind.Conveyor, Demo2MachineKind.Splitter, Demo2MachineKind.Smelter, Demo2MachineKind.Assembler, Demo2MachineKind.Loader, Demo2MachineKind.Turret, Demo2MachineKind.Generator };
            for (var i = 0; i < names.Length; i++) Require<Button>(names[i] + "-button").EnableInClassList("selected-machine", !_removeMode && kinds[i] == _selectedKind);
            Require<Button>("remove-button").EnableInClassList("selected-remove", _removeMode);
        }

        private void RefreshRules()
        {
            for (var i = 0; i < 5; i++)
            {
                if (i < _service!.RuleIds.Count && _service.Content.Rules.TryGetValue(_service.RuleIds[i], out var rule))
                {
                    SetText("rule-name-" + (i + 1), $"{i + 1}. {rule.Name}");
                    SetText("rule-description-" + (i + 1), rule.Description);
                }
                else
                {
                    SetText("rule-name-" + (i + 1), $"{i + 1}. 空槽位");
                    SetText("rule-description-" + (i + 1), "防守成功后选择规则");
                }
            }
        }

        private void RefreshRewards()
        {
            for (var i = 0; i < 3; i++)
            {
                var button = Require<Button>("reward-choose-" + (i + 1));
                Demo2RuleDefinition? rule = null;
                var available = i < _service!.RewardChoices.Count && _service.Content.Rules.TryGetValue(_service.RewardChoices[i], out rule);
                button.SetEnabled(available);
                if (!available || rule == null) continue;
                SetText("reward-category-" + (i + 1), CategoryName(rule.Category));
                SetText("reward-name-" + (i + 1), rule.Name);
                SetText("reward-description-" + (i + 1), rule.Description);
            }
        }

        private string BuildPlayerList()
        {
            if (_lan == null || _lan.Players.Count == 0) return "等待房间同步…";
            return string.Join("\n", _lan.Players.Select(player => (player.Connected ? "● " : "○ ") + player.DisplayName + (player.Ready ? "   已准备" : "   未准备")));
        }

        private void ApplySafeArea()
        {
            if (_root == null) return;
            var safe = Require<VisualElement>("safe-area");
            var area = Screen.safeArea;
            var width = Mathf.Max(1, Screen.width);
            var height = Mathf.Max(1, Screen.height);
            var panelWidth = _root.resolvedStyle.width;
            var panelHeight = _root.resolvedStyle.height;
            if (float.IsNaN(panelWidth) || float.IsNaN(panelHeight) || panelWidth <= 0 || panelHeight <= 0) return;
            safe.style.left = area.xMin / width * panelWidth;
            safe.style.right = (width - area.xMax) / width * panelWidth;
            safe.style.top = (height - area.yMax) / height * panelHeight;
            safe.style.bottom = area.yMin / height * panelHeight;
        }

        private void SyncTutorialAnchors()
        {
            if (_root == null || tutorialAnchorRoot == null) return;
            var panelWidth = Mathf.Max(1, _root.resolvedStyle.width);
            var panelHeight = Mathf.Max(1, _root.resolvedStyle.height);
            tutorialAnchorRoot.sizeDelta = new Vector2(Screen.width, Screen.height);
            foreach (var target in TutorialTargets)
            {
                if (!_tutorialAnchors.TryGetValue(target.anchorId, out var anchor)) continue;
                var element = _root.Q<VisualElement>(target.elementName);
                var displayed = element != null && IsDisplayed(element);
                anchor.gameObject.SetActive(displayed);
                if (!displayed || element == null) continue;
                var bounds = element.worldBound;
                var x = bounds.xMin / panelWidth * Screen.width;
                var y = Screen.height - bounds.yMax / panelHeight * Screen.height;
                var width = bounds.width / panelWidth * Screen.width;
                var height = bounds.height / panelHeight * Screen.height;
                anchor.anchorMin = Vector2.zero;
                anchor.anchorMax = Vector2.zero;
                anchor.pivot = Vector2.zero;
                anchor.anchoredPosition = new Vector2(x, y);
                anchor.sizeDelta = new Vector2(width, height);
            }
        }

        private static bool IsDisplayed(VisualElement element)
        {
            for (var current = element; current != null; current = current.parent)
                if (current.resolvedStyle.display == DisplayStyle.None) return false;
            return true;
        }

        private void Bind(string name, Action action) => Require<Button>(name).clicked += action;

        private T Require<T>(string name) where T : VisualElement
            => _root?.Q<T>(name) ?? throw new InvalidOperationException("Missing Demo2 UI Toolkit element: " + name);

        private void SetText(string name, string value)
        {
            var text = Require<TextElement>(name);
            text.text = value;
        }

        private void MarkDirty() => _dirty = true;

        private static string PhaseName(Demo2Phase phase) => phase switch { Demo2Phase.Build => "建造", Demo2Phase.Production => "自动生产", Demo2Phase.Defense => "炮塔结算", Demo2Phase.Reward => "规则选牌", _ => phase.ToString() };
        private static string MachineName(Demo2MachineKind kind) => kind switch { Demo2MachineKind.Miner => "采集器", Demo2MachineKind.Conveyor => "传送带", Demo2MachineKind.Splitter => "分流器", Demo2MachineKind.Smelter => "熔炼机", Demo2MachineKind.Assembler => "组装机", Demo2MachineKind.Loader => "装填器", Demo2MachineKind.Turret => "炮塔", Demo2MachineKind.Generator => "能量站", _ => kind.ToString() };
        private static string CategoryName(Demo2RuleCategory category) => category switch { Demo2RuleCategory.Production => "生产链修正", Demo2RuleCategory.Logistics => "物流条件", Demo2RuleCategory.MachineState => "机器状态", Demo2RuleCategory.CycleSettlement => "周期结算", Demo2RuleCategory.RiskExchange => "风险交换", _ => category.ToString() };
        private static void LogException(Exception exception) => Debug.LogException(exception);
    }
}