using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UIInfoBuilder.ComponentExtractors;
using UIInfoBuilder.Data;
using UnityEditor;
using UnityEngine;

namespace UIInfoBuilder
{
    public class UIInfoExtractor
    {
        private static readonly List<IComponentExtractor> _extractors = new List<IComponentExtractor>();
        private static readonly DefaultComponentExtractor _defaultExtractor = new DefaultComponentExtractor();

        static UIInfoExtractor()
        {
            // 注册特殊组件提取器（优先级高的放前面）
            _extractors.Add(new RectTransformExtractor());
            _extractors.Add(new ImageExtractor());
            _extractors.Add(new TextExtractor());
            _extractors.Add(new ButtonExtractor());
        }

        [MenuItem("Assets/UIInfoBuilder/ExtractPrefab")]
        private static void _AssetHandle()
        {
            var selectedObjects = Selection.gameObjects;
            foreach (var obj in selectedObjects)
            {
                string savePath = Application.dataPath + "/../ExtractedPrefabs/" + obj.name + ".json";
                ExtractPrefab(obj, savePath);
                Debug.Log($"[UIInfoBuilder] Extracted: {obj.name} -> {savePath}");
            }
        }

        /// <summary>
        /// 提取 Prefab 信息并保存为 JSON
        /// </summary>
        public static void ExtractPrefab(GameObject prefab, string savePath)
        {
            var rootNode = _ExtractNode(prefab);
            _SaveToJson(rootNode, savePath);
        }

        /// <summary>
        /// 递归提取节点信息
        /// </summary>
        private static UIInfoNode _ExtractNode(GameObject go)
        {
            var node = new UIInfoNode
            {
                name = go.name,
                active = go.activeSelf
            };

            // 提取所有组件
            var components = go.GetComponents<Component>();
            foreach (var component in components)
            {
                if (component == null)
                    continue;

                var compInfo = _ExtractComponent(component);
                node.components.Add(compInfo);
            }

            // 递归提取子节点
            for (int i = 0; i < go.transform.childCount; i++)
            {
                var child = go.transform.GetChild(i).gameObject;
                var childNode = _ExtractNode(child);
                node.children.Add(childNode);
            }

            return node;
        }

        /// <summary>
        /// 提取单个组件信息
        /// </summary>
        private static UIInfoComponent _ExtractComponent(Component component)
        {
            var info = new UIInfoComponent
            {
                componentName = component.GetType().Name,
                enable = _GetComponentEnabled(component)
            };

            // 查找匹配的特殊提取器
            IComponentExtractor extractor = null;
            foreach (var ext in _extractors)
            {
                if (ext.CanExtract(component))
                {
                    extractor = ext;
                    break;
                }
            }

            // 使用特殊提取器或默认提取器
            if (extractor != null)
            {
                extractor.Extract(component, info);
            }
            else
            {
                _defaultExtractor.Extract(component, info);
            }

            return info;
        }

        /// <summary>
        /// 获取组件的启用状态
        /// </summary>
        private static bool _GetComponentEnabled(Component component)
        {
            // Behaviour 类型的组件有 enabled 属性
            if (component is Behaviour behaviour)
            {
                return behaviour.enabled;
            }

            // Renderer 类型的组件有 enabled 属性
            if (component is Renderer renderer)
            {
                return renderer.enabled;
            }

            // Collider 类型的组件有 enabled 属性
            if (component is Collider collider)
            {
                return collider.enabled;
            }

            // 其他组件默认返回 true
            return true;
        }

        /// <summary>
        /// 保存为 JSON 文件
        /// </summary>
        private static void _SaveToJson(UIInfoNode node, string savePath)
        {
            // 确保目录存在
            string directory = Path.GetDirectoryName(savePath);
            if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }

            // 使用自定义递归序列化（JsonUtility 不支持嵌套 List 递归）
            var sb = new StringBuilder();
            _SerializeNode(node, sb, 0);
            File.WriteAllText(savePath, sb.ToString());
        }

        /// <summary>
        /// 递归序列化节点为 JSON
        /// </summary>
        private static void _SerializeNode(UIInfoNode node, StringBuilder sb, int indent)
        {
            string indentStr = new string(' ', indent * 2);
            string indentStr1 = new string(' ', (indent + 1) * 2);
            string indentStr2 = new string(' ', (indent + 2) * 2);
            string indentStr3 = new string(' ', (indent + 3) * 2);

            sb.AppendLine($"{indentStr}{{");
            sb.AppendLine($"{indentStr1}\"name\": \"{_EscapeJsonString(node.name)}\",");
            sb.AppendLine($"{indentStr1}\"active\": {node.active.ToString().ToLower()},");

            // Components
            sb.AppendLine($"{indentStr1}\"components\": [");
            for (int i = 0; i < node.components.Count; i++)
            {
                var comp = node.components[i];
                sb.AppendLine($"{indentStr2}{{");
                sb.AppendLine($"{indentStr3}\"componentName\": \"{_EscapeJsonString(comp.componentName)}\",");
                sb.AppendLine($"{indentStr3}\"enable\": {comp.enable.ToString().ToLower()},");
                sb.Append($"{indentStr3}\"properties\": [");
                
                if (comp.properties.Count > 0)
                {
                    sb.AppendLine();
                    for (int j = 0; j < comp.properties.Count; j++)
                    {
                        string comma = j < comp.properties.Count - 1 ? "," : "";
                        sb.AppendLine($"{indentStr3}  \"{_EscapeJsonString(comp.properties[j])}\"{comma}");
                    }
                    sb.AppendLine($"{indentStr3}]");
                }
                else
                {
                    sb.AppendLine("]");
                }

                string compComma = i < node.components.Count - 1 ? "," : "";
                sb.AppendLine($"{indentStr2}}}{compComma}");
            }
            sb.AppendLine($"{indentStr1}],");

            // Children
            sb.AppendLine($"{indentStr1}\"children\": [");
            for (int i = 0; i < node.children.Count; i++)
            {
                _SerializeNode(node.children[i], sb, indent + 2);
                if (i < node.children.Count - 1)
                {
                    // 在上一个 } 后面加逗号
                    sb.Length -= Environment.NewLine.Length; // 移除换行
                    sb.AppendLine(",");
                }
            }
            sb.AppendLine($"{indentStr1}]");

            sb.AppendLine($"{indentStr}}}");
        }

        /// <summary>
        /// 转义 JSON 字符串中的特殊字符
        /// </summary>
        private static string _EscapeJsonString(string str)
        {
            if (string.IsNullOrEmpty(str))
                return str;

            return str
                .Replace("\\", "\\\\")
                .Replace("\"", "\\\"")
                .Replace("\n", "\\n")
                .Replace("\r", "\\r")
                .Replace("\t", "\\t");
        }
    }
}