using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Xml.Linq;
using Configs;
using UnityEngine;

namespace Data
{
    public class PackAbout
    {
        public string name;
        public string description;
        public string author;
        public string version;
        public string packID;

        public string[] necessary;
        public string[] after;
        public string[] before;

        /// <summary>
        ///     使用静态方法从 XML 文档创建 PackAbout 实例。
        /// </summary>
        /// <param name="doc">XML 文档。</param>
        /// <returns>初始化的 PackAbout 实例。</returns>
        public static PackAbout FromXDocument(XDocument doc)
        {
            var aboutElement = doc.Element("About");
            if (aboutElement == null) throw new ArgumentException("XML 文档无效，根节点为空或不是 'About'。");
            PackAbout result = new();

            result.name = aboutElement.Element("name")?.Value ?? "Unknown";
            result.description = aboutElement.Element("description")?.Value ?? "Unknown";
            result.author = aboutElement.Element("author")?.Value ?? "Unknown";
            result.version = aboutElement.Element("version")?.Value ?? "Unknown";
            result.packID = aboutElement.Element("packID")?.Value ?? "Unknown";

            var sortElement = aboutElement.Element("sort");
            if (sortElement != null)
            {
                result.before = GetElementValues(sortElement.Element("before"));
                result.after = GetElementValues(sortElement.Element("after"));
                result.necessary = GetElementValues(sortElement.Element("necessary"));
            }
            else
            {
                result.before = Array.Empty<string>();
                result.after = Array.Empty<string>();
                result.necessary = Array.Empty<string>();
            }

            return result;
        }

        /// <summary>
        ///     获取指定 XElement 下所有子元素的值并返回为字符串数组。
        /// </summary>
        /// <param name="element">父 XElement。</param>
        /// <returns>字符串数组。</returns>
        private static string[] GetElementValues(XElement element)
        {
            if (element == null || !element.HasElements) return Array.Empty<string>();

            return element.Elements()
                .Select(e => e.Value.Trim())
                .ToArray();
        }

        public override string ToString()
        {
            // 定义字段标签和值的对齐格式（如左对齐，固定宽度）
            const int labelWidth = -12; // 负数为左对齐
            const int valueWidth = -30; // 负数为左对齐

            // 使用StringBuilder高效拼接
            var sb = new StringBuilder();

            // 基础字段（单行）
            sb.AppendLine($"{"Name:",labelWidth}{name,valueWidth}");
            sb.AppendLine($"{"Description:",labelWidth}{description,valueWidth}");
            sb.AppendLine($"{"Author:",labelWidth}{author,valueWidth}");
            sb.AppendLine($"{"Version:",labelWidth}{version,valueWidth}");
            sb.AppendLine($"{"PackID:",labelWidth}{packID,valueWidth}");

            // 数组字段（多行，每项缩进）
            sb.AppendLine(
                $"{"Necessary:",labelWidth}{string.Join(", ", necessary ?? Array.Empty<string>()),valueWidth}");
            sb.AppendLine($"{"After:",labelWidth}{string.Join(", ", after ?? Array.Empty<string>()),valueWidth}");
            sb.AppendLine($"{"Before:",labelWidth}{string.Join(", ", before ?? Array.Empty<string>()),valueWidth}");

            return sb.ToString();
        }
    }

    public class DefinePack
    {
        private const string CoreNamespace = "Data.";

        /// <summary>
        ///     define类别及其定义
        /// </summary>
        public Dictionary<string, List<Define>> defines;

        public PackAbout packAbout;
        public string packID;


        public bool LoadPack(string packPath)
        {
            var packDatas = ConfigProcessor.LoadXmlFromPath(packPath);
            var aboutXmls = FindDocumentsWithRootName(packDatas, "About");
            if (aboutXmls == null || aboutXmls.Count < 1)
            {
                Debug.LogError("包缺少配置文件，加载跳过");
                return false;
            }

            var aboutXml = aboutXmls[0];
            packAbout = PackAbout.FromXDocument(aboutXml);
            packID = packAbout.packID;
            if (aboutXmls.Count > 1) Debug.LogWarning($"{packAbout.name}包拥有多个配置文件，系统选择了加载序的第一个，请避免这种情况");

            var defineXmls = FindDocumentsWithRootName(aboutXmls, "Define");
            foreach (var defineXml in defineXmls) LoadDefines(defineXml);

            return true;
        }

        private void LoadDefines(XDocument defineDoc)
        {
            var rootElement = defineDoc.Root;
            if (rootElement == null || rootElement.Name != "Define")
                return;

            foreach (var element in rootElement.Elements())
            {
                var className = element.Name.ToString();
                if (string.IsNullOrEmpty(className))
                    continue;
                var def = LoadDefineClass(element);
                if (def == null)
                    continue;
                if (!defines.ContainsKey(className))
                    defines.Add(className, new List<Define>());
                defines[className].Add(def);
            }
        }

        private Define LoadDefineClass(XElement defineDoc)
        {
            var className = defineDoc.Name.ToString();
            var assembly = Assembly.GetExecutingAssembly();

            Type type;
            if (!className.Contains('.'))
            {
                // 尝试拼接默认命名空间   
                var fullClassName = CoreNamespace + className;
                type = assembly.GetType(fullClassName);

                // 如果拼接命名空间后仍找不到，尝试直接查找（可能是全局命名空间下的类）
                if (type == null) type = assembly.GetType(className);
            }
            else
            {
                // 直接查找
                type = assembly.GetType(className);
            }

            if (type == null)
            {
                Debug.LogError($"未定义的类型: {className}");
                return null;
            }

            var constructor = type.GetConstructor(Type.EmptyTypes);
            if (constructor == null)
            {
                Debug.LogError($"{className} 必须包含无参构造函数");
                return null;
            }

            // 3. 创建实例
            object instance;
            try
            {
                instance = Activator.CreateInstance(type);
            }
            catch (Exception ex)
            {
                Debug.LogError($"创建 {className} 实例失败: {ex.Message}");
                return null;
            }

            // 4. 检查是否继承自 Define
            if (instance is not Define define)
            {
                Debug.LogError($"{className} 必须继承自 Define");
                return null;
            }

            if (define.Init(defineDoc)) return define;
            // 获取类的所有字段（不包括私有字段）
            var fields = type.GetFields(BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic);

            // 遍历字段并尝试从 XElement 中赋值
            foreach (var field in fields)
            {
                // 查找对应的 XElement 子元素
                var element = defineDoc.Element(field.Name);
                if (element != null)
                    try
                    {
                        // 将子元素的值转换为目标类型并赋值
                        var value = Convert.ChangeType(element.Value, field.FieldType);
                        field.SetValue(define, value);
                    }
                    catch (Exception ex)
                    {
                        Debug.LogWarning($"Error setting field {field.Name}: {ex.Message}");
                    }
            }

            return define;
        }

        /// <summary>
        ///     从 List<c>XDocument</c> 中查找指定根元素名称的文档。
        /// </summary>
        /// <param name="xmlDocuments">XML 文档列表。</param>
        /// <param name="rootName">目标根元素名称。</param>
        /// <returns>符合条件的 XML 文档列表。</returns>
        public static List<XDocument> FindDocumentsWithRootName(List<XDocument> xmlDocuments, string rootName)
        {
            // Using LINQ to Objects for a more concise solution
            var result = xmlDocuments
                .Where(doc => doc.Root != null && doc.Root.Name.LocalName == rootName)
                .ToList();

            return result;
        }

        public override string ToString()
        {
            // 对齐格式（左对齐，固定宽度）
            const int labelWidth = -15;
            const int valueWidth = -30;

            var sb = new StringBuilder();

            // 基础字段
            sb.AppendLine($"{"PackID:",labelWidth}{packID,valueWidth}");
            sb.AppendLine();

            // PackAbout 对象
            sb.AppendLine("=== PackAbout ===");
            sb.AppendLine(packAbout?.ToString() ?? "N/A"); // 调用 PackAbout 的 ToString()
            sb.AppendLine();

            // 字典字段（defines）
            sb.AppendLine("=== Defines ===");
            if (defines != null && defines.Count > 0)
                foreach (var kvp in defines)
                {
                    sb.AppendLine($"【{kvp.Key}】"); // 输出字典的键（类别名）
                    foreach (var define in kvp.Value) // 遍历该类别下的所有 Define 对象
                        sb.AppendLine(define.ToString()); // 调用 Define 的 ToString()
                    sb.AppendLine(); // 每个类别后空一行
                }
            else
                sb.AppendLine("No defines found.");

            return sb.ToString();
        }
    }
}