using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using UnityEngine;

namespace Data
{


    public struct 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"); // Assuming "about" is the root element name
            if (aboutElement == null)
            {
                throw new ArgumentException("XML 文档无效，根节点为空或不是 'About'。");
            }

            // Initialize PackAbout instance
            PackAbout result = new();

            // Read element content
            result.name = aboutElement.Element("name")?.Value ?? "Unknown";
            result.description = aboutElement.Element("description")?.Value ?? "Unknown";
            result.author = aboutElement.Element("author")?.Value ?? "Unknown"; // Assuming 'author' is also a direct child
            result.version = aboutElement.Element("version")?.Value ?? "Unknown";
            result.packID = aboutElement.Element("packID")?.Value ?? "Unknown";

            // Read child elements under the "sort" element
            XElement 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 = System.Array.Empty<string>();
                result.after = System.Array.Empty<string>();
                result.necessary = System.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 System.Array.Empty<string>();
            }

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

    public class DefinePack
    {
        public string packID;
        public PackAbout packAbout;
        public List<Define> defines;

        public bool LoadPack(string packPath)
        {
            var packDatas=Utils.FileHandler.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)
        {
            
        }
        
        /// <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;
        }
    }
}