using System;
using System.Collections.Generic;
using Cielonos.MainGame;
using Cielonos.MainGame.Inventory;
using Cielonos.MainGame.Inventory.Collections;
using Sirenix.OdinInspector;
using SLSUtilities.General;
using SLSUtilities.UI;
using UnityEngine;

namespace Cielonos.MainGame.UI
{
    public enum NotificationType
    {
        ItemObtained,
        CurrencyChanged,
        BattleCompleted,
        Warning,
        System
    }

    [Serializable]
    public struct NotificationData
    {
        public NotificationType type;
        public string title;
        public string message;
        public Sprite icon;
        public Color accentColor;
        public float duration;

        public NotificationData(
            NotificationType type,
            string title,
            string message,
            Sprite icon,
            Color accentColor,
            float duration)
        {
            this.type = type;
            this.title = title;
            this.message = message;
            this.icon = icon;
            this.accentColor = accentColor;
            this.duration = duration;
        }
    }

    /// <summary>
    /// 右上角通用提示队列。该 UI 不阻塞输入，也不参与 UIPageManager 的页面栈。
    /// </summary>
    public class NotificationUIArea : UIElementBase
    {
        public static NotificationUIArea Current { get; private set; }

        [SerializeField] private NotificationItem itemPrefab;
        [SerializeField] private RectTransform itemContainer;
        [SerializeField] private BattleCompletionBanner battleCompletionBanner;
        [SerializeField, Min(1)] private int maxVisible = 4;
        [SerializeField, Min(1f)] private float itemHeight = 100f;
        [SerializeField, Min(0f)] private float itemSpacing = 10f;
        [SerializeField, Min(0f)] private float defaultDuration = 3f;
        [SerializeField, Min(0f)] private float enterDuration = 0.25f;
        [SerializeField, Min(0f)] private float moveDuration = 0.2f;
        [SerializeField, Min(0f)] private float exitDuration = 0.2f;
        [SerializeField, Min(0f)] private float queueWaitTime = 0.12f;
        [SerializeField] private Color defaultAccentColor = new Color(0.7f, 0.85f, 1f, 1f);
        [SerializeField] private Color currencyAccentColor = new Color(1f, 0.82f, 0.35f, 1f);
        [SerializeField] private Color warningAccentColor = new Color(1f, 0.4f, 0.35f, 1f);
        [SerializeField] private string battleCompletedMessage = "战斗结束";

        private readonly List<NotificationItem> activeItems = new();
        private readonly Queue<NotificationData> pendingItems = new();
        private bool roomClearedSubscribed;
        private float nextSpawnTime;

        private float StackStep => itemHeight + itemSpacing;

        private void Awake()
        {
            Current = this;
            rectTransform ??= GetComponent<RectTransform>();
            canvasGroup ??= GetComponent<CanvasGroup>();
            itemContainer ??= rectTransform;
            battleCompletionBanner ??= GetComponentInChildren<BattleCompletionBanner>(true);

            if (canvasGroup != null)
            {
                canvasGroup.alpha = 1f;
                canvasGroup.interactable = false;
                canvasGroup.blocksRaycasts = false;
            }
        }

        private void Start()
        {
            gameObject.SetActive(true);
            TrySubscribeRoomCleared();
        }

        private void OnEnable()
        {
            Current = this;
            TrySubscribeRoomCleared();
        }

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

            UnsubscribeRoomCleared();
        }

        private void Update()
        {
            if (!roomClearedSubscribed)
            {
                TrySubscribeRoomCleared();
            }

            ProcessPendingItems();
        }

        public void Push(NotificationData data)
        {
            if (itemPrefab == null || itemContainer == null)
            {
                Debug.LogWarning("[NotificationUIArea] itemPrefab 或 itemContainer 未配置。");
                return;
            }

            EnsureAreaVisible();
            pendingItems.Enqueue(PrepareData(data));
            ProcessPendingItems();
        }

        public void PushBattleCompleted()
        {
            if (battleCompletionBanner != null)
            {
                battleCompletionBanner.Show(battleCompletedMessage);
                return;
            }

            Push(new NotificationData(
                NotificationType.BattleCompleted,
                "战斗完成",
                battleCompletedMessage,
                null,
                defaultAccentColor,
                defaultDuration));
        }

        [TitleGroup("Debug")]
        [Button("生成测试 Notification")]
        private void PushTestNotification()
        {
            Push(new NotificationData(
                NotificationType.System,
                "测试通知",
                $"Notification Test {DateTime.Now:HH:mm:ss}",
                null,
                defaultAccentColor,
                defaultDuration));
        }

        public void PushItemObtained(ItemBase item, int amount = 1)
        {
            if (item == null)
            {
                return;
            }

            Push(CreateItemObtainedData(item, amount));
        }

        public void PushRareMaterial(int amount, string title = "奖励结算")
        {
            string message = amount > 0
                ? $"获得 RareMaterial x{amount}"
                : "未获得 RareMaterial";

            Push(new NotificationData(
                NotificationType.CurrencyChanged,
                title,
                message,
                null,
                currencyAccentColor,
                defaultDuration));
        }

        public void PushWarning(string title, string message)
        {
            Push(new NotificationData(
                NotificationType.Warning,
                title,
                message,
                null,
                warningAccentColor,
                defaultDuration));
        }

        public static NotificationData CreateItemObtainedData(ItemBase item, int amount = 1)
        {
            ContentData data = item?.contentData;
            if (item is PrefabricatedComponent component && component.targetEquipment != null)
            {
                data = component.targetEquipment.contentData;
            }

            string itemName = data != null && !string.IsNullOrEmpty(data.displayNameKey)
                ? data.displayNameKey.Localize("Items")
                : item != null ? item.name : "Unknown Item";

            bool isUpgrade = item is PrefabricatedComponent;
            string title = isUpgrade ? "装备升级" : "获得物品";
            string message = isUpgrade
                ? $"升级：{itemName} x{Mathf.Max(1, amount)}"
                : $"{itemName} x{Mathf.Max(1, amount)}";

            return new NotificationData(
                NotificationType.ItemObtained,
                title,
                message,
                data?.itemIcon,
                GetItemAccentColor(data),
                3f);
        }

        private static Color GetItemAccentColor(ContentData data)
        {
            return data != null
                ? RewardUIFormatter.GetRarityColor(data.itemRarity)
                : new Color(0.7f, 0.85f, 1f, 1f);
        }

        private NotificationData PrepareData(NotificationData data)
        {
            if (data.accentColor.a <= 0f)
            {
                data.accentColor = defaultAccentColor;
            }

            if (data.duration <= 0f)
            {
                data.duration = defaultDuration;
            }

            return data;
        }

        private void ProcessPendingItems()
        {
            if (pendingItems.Count == 0 || itemPrefab == null || itemContainer == null || maxVisible < 1)
            {
                return;
            }

            if (Time.unscaledTime < nextSpawnTime)
            {
                return;
            }

            SpawnItem(pendingItems.Dequeue());
            nextSpawnTime = Time.unscaledTime + queueWaitTime;
        }

        private void SpawnItem(NotificationData data)
        {
            CleanupDestroyedItems();
            while (activeItems.Count >= maxVisible)
            {
                RemoveOldest();
            }

            NotificationItem item = Instantiate(itemPrefab, itemContainer);
            if (item == null)
            {
                return;
            }

            activeItems.Insert(0, item);
            item.Setup(data, defaultDuration);
            ApplyLayout(true);
            item.PlayIn(GetTargetPosition(0), enterDuration, () => Remove(item));
        }

        private void ApplyLayout(bool animate)
        {
            CleanupDestroyedItems();

            for (int i = 0; i < activeItems.Count; i++)
            {
                NotificationItem item = activeItems[i];
                if (item == null)
                {
                    continue;
                }

                Vector2 target = GetTargetPosition(i);
                if (animate && i > 0)
                {
                    item.MoveTo(target, moveDuration);
                }
                else
                {
                    item.SetPosition(target);
                }
            }
        }

        private Vector2 GetTargetPosition(int index)
        {
            // itemContainer 应锚定在右上角。新提示位于堆栈底部，旧提示向上移动。
            Rect rect = itemContainer != null
                ? itemContainer.rect
                : new Rect(0f, 0f, 0f, maxVisible * StackStep);
            float pivotY = itemContainer != null ? itemContainer.pivot.y : 0.5f;
            float bottom = -rect.height * pivotY;
            float baseline = bottom + itemHeight * 0.5f;
            return new Vector2(0f, baseline + index * StackStep);
        }

        private void RemoveOldest()
        {
            int lastIndex = activeItems.Count - 1;
            if (lastIndex < 0)
            {
                return;
            }

            NotificationItem oldest = activeItems[lastIndex];
            activeItems.RemoveAt(lastIndex);
            if (oldest != null)
            {
                oldest.DismissImmediate(null);
            }
        }

        private void Remove(NotificationItem item)
        {
            if (item == null)
            {
                return;
            }

            if (!activeItems.Remove(item))
            {
                return;
            }

            item.PlayOut(null, exitDuration);
            ApplyLayout(true);
        }

        private void CleanupDestroyedItems()
        {
            activeItems.RemoveAll(item => item == null);
        }

        private void EnsureAreaVisible()
        {
            if (!gameObject.activeSelf)
            {
                gameObject.SetActive(true);
            }

            if (canvasGroup == null)
            {
                return;
            }

            canvasGroup.alpha = 1f;
            canvasGroup.interactable = false;
            canvasGroup.blocksRaycasts = false;
        }

        private void TrySubscribeRoomCleared()
        {
            if (roomClearedSubscribed || RunManager.Instance == null)
            {
                return;
            }

            RunManager.Instance.OnCombatRoomCleared += HandleCombatRoomCleared;
            roomClearedSubscribed = true;
        }

        private void UnsubscribeRoomCleared()
        {
            if (!roomClearedSubscribed || RunManager.Instance == null)
            {
                roomClearedSubscribed = false;
                return;
            }

            RunManager.Instance.OnCombatRoomCleared -= HandleCombatRoomCleared;
            roomClearedSubscribed = false;
        }

        private void HandleCombatRoomCleared(RunMapNode node)
        {
            PushBattleCompleted();
        }

        public static NotificationUIArea Resolve()
        {
            if (Current != null)
            {
                return Current;
            }

            Current = FindFirstObjectByType<NotificationUIArea>(FindObjectsInactive.Include);
            return Current;
        }
    }
}