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

namespace DesignTools.Common
{
    [Serializable]
    public class DesignToolItemPickerItem
    {
        public int Id;
        public string Name;
        public int IType;
    }

    /// <summary>
    /// 通用 Item 选择窗口
    /// 支持按类型筛选、按 Id/名称搜索、分页浏览与回填选择结果
    /// </summary>
    public class DesignToolItemPickerWindow : EditorWindow
    {
        private readonly List<DesignToolItemPickerItem> allItems = new List<DesignToolItemPickerItem>();
        private readonly List<int> allItemTypes = new List<int>();
        private readonly Dictionary<int, string> itemTypeNames = new Dictionary<int, string>();

        private Vector2 scrollPosition;
        private string searchText = "";
        private int selectedType = -1;
        private int currentItemId;
        private int currentPage;
        private const int ITEMS_PER_PAGE = 20;

        private Action<int> onItemSelected;

        public static void ShowWindow(
            List<DesignToolItemPickerItem> items,
            List<int> itemTypes,
            Dictionary<int, string> typeNames,
            int currentType,
            int selectedItemId,
            Rect ownerWindowRect,
            Action<int> onSelected)
        {
            DesignToolItemPickerWindow window = CreateInstance<DesignToolItemPickerWindow>();
            window.titleContent = new GUIContent("选择道具");
            window.minSize = new Vector2(700, 520);
            window.allItems.Clear();
            window.allItems.AddRange(items.OrderBy(x => x.IType).ThenBy(x => x.Id));
            window.allItemTypes.Clear();
            window.allItemTypes.AddRange(itemTypes);
            window.itemTypeNames.Clear();
            foreach (KeyValuePair<int, string> pair in typeNames)
            {
                window.itemTypeNames[pair.Key] = pair.Value;
            }

            window.selectedType = currentType;
            window.currentItemId = selectedItemId;
            window.onItemSelected = onSelected;
            window.position = GetCenteredRect(ownerWindowRect, window.minSize);
            window.ShowModalUtility();
        }

        private static Rect GetCenteredRect(Rect ownerWindowRect, Vector2 windowSize)
        {
            float x = ownerWindowRect.x + (ownerWindowRect.width - windowSize.x) * 0.5f;
            float y = ownerWindowRect.y + (ownerWindowRect.height - windowSize.y) * 0.5f;
            return new Rect(x, y, windowSize.x, windowSize.y);
        }

        private void OnGUI()
        {
            DrawToolbar();
            EditorGUILayout.Space(4);
            DrawList();
        }

        private void DrawToolbar()
        {
            EditorGUILayout.BeginVertical("box");

            EditorGUILayout.BeginHorizontal();
            EditorGUILayout.LabelField("搜索", GUILayout.Width(40));
            string newSearchText = EditorGUILayout.TextField(searchText);
            if (newSearchText != searchText)
            {
                searchText = newSearchText;
                currentPage = 0;
            }

            if (GUILayout.Button("清空", GUILayout.Width(50)))
            {
                searchText = "";
                GUI.FocusControl(null);
                currentPage = 0;
            }
            EditorGUILayout.EndHorizontal();

            EditorGUILayout.BeginHorizontal();
            List<string> typeOptions = new List<string> { "全部类型" };
            typeOptions.AddRange(allItemTypes.Select(GetTypeDisplayName));

            int selectedIndex = 0;
            if (selectedType >= 0)
            {
                int typeIndex = allItemTypes.IndexOf(selectedType);
                selectedIndex = typeIndex >= 0 ? typeIndex + 1 : 0;
            }

            int newIndex = EditorGUILayout.Popup("类型", selectedIndex, typeOptions.ToArray(),GUILayout.Width(420));
            int newType = newIndex == 0 ? -1 : allItemTypes[newIndex - 1];
            if (newType != selectedType)
            {
                selectedType = newType;
                currentPage = 0;
            }

            GUILayout.FlexibleSpace();
            EditorGUILayout.EndHorizontal();

            EditorGUILayout.HelpBox("棋子上的宝箱如果是两个，id奇数是未解锁的，偶数是已解锁的", MessageType.Info);

            EditorGUILayout.EndVertical();
        }

        private void DrawList()
        {
            List<DesignToolItemPickerItem> filteredItems = allItems
                .Where(MatchFilter)
                .ToList();

            int totalPages = Mathf.Max(1, Mathf.CeilToInt(filteredItems.Count / (float)ITEMS_PER_PAGE));
            currentPage = Mathf.Clamp(currentPage, 0, totalPages - 1);

            EditorGUILayout.BeginHorizontal();
            EditorGUILayout.LabelField($"共 {filteredItems.Count} 个道具", GUILayout.Width(120));
            GUILayout.FlexibleSpace();

            GUI.enabled = currentPage > 0;
            if (GUILayout.Button("<", GUILayout.Width(30)))
            {
                currentPage--;
            }

            GUI.enabled = currentPage < totalPages - 1;
            if (GUILayout.Button(">", GUILayout.Width(30)))
            {
                currentPage++;
            }
            GUI.enabled = true;

            EditorGUILayout.LabelField($"第 {currentPage + 1}/{totalPages} 页", GUILayout.Width(90));
            EditorGUILayout.EndHorizontal();

            EditorGUILayout.Space(4);
            scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition);

            IEnumerable<DesignToolItemPickerItem> pageItems = filteredItems
                .Skip(currentPage * ITEMS_PER_PAGE)
                .Take(ITEMS_PER_PAGE);

            foreach (DesignToolItemPickerItem item in pageItems)
            {
                DrawItemRow(item);
            }

            EditorGUILayout.EndScrollView();
        }

        private void DrawItemRow(DesignToolItemPickerItem item)
        {
            bool isCurrent = item.Id == currentItemId;
            GUI.backgroundColor = isCurrent ? new Color(0.8f, 1f, 0.8f) : Color.white;

            EditorGUILayout.BeginVertical("box");
            EditorGUILayout.BeginHorizontal();
            EditorGUILayout.LabelField(item.Id.ToString(), GUILayout.Width(70));
            EditorGUILayout.LabelField(item.Name, GUILayout.Width(280));
            EditorGUILayout.LabelField(GetTypeDisplayName(item.IType), GUILayout.Width(160));
            GUILayout.FlexibleSpace();

            if (GUILayout.Button("选择", GUILayout.Width(60)))
            {
                onItemSelected?.Invoke(item.Id);
                Close();
            }
            EditorGUILayout.EndHorizontal();
            EditorGUILayout.EndVertical();

            GUI.backgroundColor = Color.white;
        }

        private bool MatchFilter(DesignToolItemPickerItem item)
        {
            if (selectedType >= 0 && item.IType != selectedType)
            {
                return false;
            }

            if (string.IsNullOrWhiteSpace(searchText))
            {
                return true;
            }

            return item.Id.ToString().Contains(searchText, StringComparison.OrdinalIgnoreCase) ||
                   (!string.IsNullOrEmpty(item.Name) && item.Name.Contains(searchText, StringComparison.OrdinalIgnoreCase));
        }

        private string GetTypeDisplayName(int itemType)
        {
            return itemTypeNames.TryGetValue(itemType, out string typeName)
                ? $"{typeName} ({itemType})"
                : $"类型 {itemType}";
        }
    }
}