using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WIDESEAWCS_Core.Helper;

namespace WIDESEAWCS_Core.LogHelper
{
    public class LoggerHelper
    {
        // 读写锁，确保多线程环境下日志写入的线程安全
        static ReaderWriterLockSlim LogWriteLock = new ReaderWriterLockSlim();

        // 日志文件夹路径
        static string folderPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, $"Log");

        // 记录日志的队列
        static Queue<string> logQueue = new Queue<string>();

        static LoggerHelper()
        {
            try
            {
                if (!Directory.Exists(folderPath))
                {
                    Directory.CreateDirectory(folderPath);
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="ex"></param>
        /// <param name="filePath"></param>
        public static void WriteError(Exception ex, string filePath = "")
        {
            StringBuilder builder = new StringBuilder();
            builder.Append("错误信息：");
            builder.Append(ex.Message);
            builder.Append(Environment.NewLine);
            builder.Append("错误源：");
            builder.Append(ex.Source);
            builder.Append(Environment.NewLine);
            builder.Append("错误堆栈：");
            builder.Append(ex.StackTrace);
            builder.Append(Environment.NewLine);
            builder.Append("错误类型：");
            builder.Append(ex.GetType().ToString());
            builder.Append(Environment.NewLine);
            builder.Append("错误方法：");
            builder.Append(ex.TargetSite?.ToString());
            builder.Append(Environment.NewLine);
            builder.Append(Environment.NewLine);

            WriteLogToFile($"Error_", builder.ToString(), filePath);
        }

        /// <summary>
        /// 将日志内容写入指定文件
        /// </summary>
        /// <param name="fileName">日志文件名</param>
        /// <param name="log">要记录的日志内容</param>
        /// <remarks>
        /// 该方法会确保线程安全地写入日志，若目录不存在会自动创建，
        /// 日志内容会自动添加时间戳并追加到文件末尾
        /// </remarks>
        public static void WriteLogToFile(string fileName, string log, string filePath = "")
        {
            try
            {
                // 进入写锁
                LogWriteLock.EnterWriteLock();

                string path = string.IsNullOrEmpty(filePath) ? folderPath : filePath;

                // 如果文件夹不存在，则创建文件夹
                if (!Directory.Exists(path))
                {
                    Directory.CreateDirectory(path);
                }
                // 获取日志文件路径
                string logFilePath = Path.Combine(path, GetLastAccessFileName(fileName, path));
                // 获取当前时间
                DateTime now = DateTime.Now;
                // 构造日志内容
                string logContent = $"【{now}】{Environment.NewLine}{log}";

                // 将日志内容追加到日志文件中
                File.AppendAllText(logFilePath, logContent);

                WriteCompleted();
            }
            catch { }
            finally
            {
                // 退出写锁
                LogWriteLock.ExitWriteLock();
            }
        }
        static int size = 10 * 1024 * 1024;

        /// <summary>
        /// 获取最后一个可用的日志文件名
        /// </summary>
        /// <param name="fileName">日志文件基础名称</param>
        /// <returns>如果存在未达到大小限制的日志文件则返回该文件名，否则返回基于当前时间的新日志文件名</returns>
        /// <remarks>
        /// 该方法会遍历所有已存在的日志文件，返回第一个文件大小未超过限制的文件名。
        /// 如果没有符合条件的文件，则生成一个以当前时间命名的新日志文件名。
        /// </remarks>
        private static string GetLastAccessFileName(string fileName, string path)
        {
            foreach (var m in GetExistLogFileNames(fileName, path))
            {
                FileInfo fileInfo = new FileInfo(m);
                if (fileInfo.Length < size)
                {
                    return m;
                }
            }

            // 返回一个新的默认当前时间的日志名称
            return $@"{fileName}_{DateTime.Now.ToString("yyyyMMddHHmmss")}.log";
        }

        /// <summary>
        /// 获取指定文件名模式的所有日志文件
        /// </summary>
        /// <param name="fileName">日志文件名前缀</param>
        /// <returns>匹配文件名模式的所有日志文件路径数组</returns>
        private static string[] GetExistLogFileNames(string fileName, string path)
        {
            string[] fileNames = Directory.GetFiles(path, fileName + "*.log");
            return fileNames;
        }

        private static string[] GetExistLogFileNames()
        {
            if (!string.IsNullOrEmpty(folderPath))
                return Directory.GetFiles(folderPath, "Error_*.log");
            else
                return new string[] { };
        }

        private static int controlFileQuantity = 100;

        protected static void WriteCompleted()
        {
            if (controlFileQuantity > 1)
            {
                try
                {
                    string[] files = GetExistLogFileNames();
                    if (files.Length > controlFileQuantity)
                    {
                        List<FileInfo> fileInfos = new List<FileInfo>();
                        for (int i = 0; i < files.Length; i++)
                        {
                            fileInfos.Add(new FileInfo(files[i]));
                        }

                        fileInfos.Sort(new Comparison<FileInfo>((m, n) =>
                        {
                            return m.CreationTime.CompareTo(n.CreationTime);
                        }));

                        for (int i = 0; i < fileInfos.Count - controlFileQuantity; i++)
                        {
                            File.Delete(fileInfos[i].FullName);
                        }
                    }
                }
                catch
                {

                }
            }
        }
    }
}