using System;
using System.ComponentModel;
using System.Reflection;
using System.Runtime;
using System.Runtime.InteropServices;
using System.Text;

namespace NewLife.Log
{
    /// <summary>日志基类。提供日志的基本实现</summary>
    [EditorBrowsable(EditorBrowsableState.Advanced)]
    public abstract class Logger : ILog
    {
        #region 主方法
        /// <summary>调试日志</summary>
        /// <param name="format">格式化字符串</param>
        /// <param name="args">格式化参数</param>
        public virtual void Debug(String format, params Object[] args) => Write(LogLevel.Debug, format, args);

        /// <summary>信息日志</summary>
        /// <param name="format">格式化字符串</param>
        /// <param name="args">格式化参数</param>
        public virtual void Info(String format, params Object[] args) => Write(LogLevel.Info, format, args);

        /// <summary>警告日志</summary>
        /// <param name="format">格式化字符串</param>
        /// <param name="args">格式化参数</param>
        public virtual void Warn(String format, params Object[] args) => Write(LogLevel.Warn, format, args);

        /// <summary>错误日志</summary>
        /// <param name="format">格式化字符串</param>
        /// <param name="args">格式化参数</param>
        public virtual void Error(String format, params Object[] args) => Write(LogLevel.Error, format, args);

        /// <summary>严重错误日志</summary>
        /// <param name="format">格式化字符串</param>
        /// <param name="args">格式化参数</param>
        public virtual void Fatal(String format, params Object[] args) => Write(LogLevel.Fatal, format, args);
        #endregion

        #region 核心方法
        /// <summary>写日志</summary>
        /// <param name="level"></param>
        /// <param name="format"></param>
        /// <param name="args"></param>
        public virtual void Write(LogLevel level, String format, params Object[] args)
        {
            if (Enable && level >= Level) OnWrite(level, format, args);
        }

        /// <summary>写日志</summary>
        /// <param name="level"></param>
        /// <param name="format"></param>
        /// <param name="args"></param>
        protected abstract void OnWrite(LogLevel level, String format, params Object[] args);
        #endregion

        #region 辅助方法
        /// <summary>格式化参数，特殊处理异常和时间</summary>
        /// <param name="format"></param>
        /// <param name="args"></param>
        /// <returns></returns>
        protected virtual String Format(String format, Object[] args)
        {
            //处理时间的格式化
            if (args != null && args.Length > 0)
            {
                // 特殊处理异常
                if (args.Length == 1 && args[0] is Exception ex && (format.IsNullOrEmpty() || format == "{0}"))
                    return ex.GetMessage();

                for (var i = 0; i < args.Length; i++)
                {
                    if (args[i] != null && args[i].GetType() == typeof(DateTime))
                    {
                        // 根据时间值的精确度选择不同的格式化输出
                        var dt = (DateTime)args[i];
                        if (dt.Millisecond > 0)
                            args[i] = dt.ToString("yyyy-MM-dd HH:mm:ss.fff");
                        else if (dt.Hour > 0 || dt.Minute > 0 || dt.Second > 0)
                            args[i] = dt.ToString("yyyy-MM-dd HH:mm:ss");
                        else
                            args[i] = dt.ToString("yyyy-MM-dd");
                    }
                }
            }
            if (args == null || args.Length < 1) return format;

            //format = format.Replace("{", "{{").Replace("}", "}}");

            return String.Format(format, args);
        }
        #endregion

        #region 属性
        /// <summary>是否启用日志。默认true</summary>
        public virtual Boolean Enable { get; set; } = true;

        private LogLevel? _Level;
        /// <summary>日志等级，只输出大于等于该级别的日志，默认Info，打开NewLife.Debug时默认为最低的Debug</summary>
        public virtual LogLevel Level
        {
            get
            {
                if (_Level != null) return _Level.Value;

                return Setting.Current.LogLevel;
            }
            set { _Level = value; }
        }
        #endregion

        #region 静态空实现
        /// <summary>空日志实现</summary>
        public static ILog Null { get; } = new NullLogger();

        class NullLogger : Logger
        {
            public override Boolean Enable { get => false; set { } }

            protected override void OnWrite(LogLevel level, String format, params Object[] args) { }
        }
        #endregion

        #region 日志头
        /// <summary>输出日志头，包含所有环境信息</summary>
        protected static String GetHead()
        {
            var process = System.Diagnostics.Process.GetCurrentProcess();
            var name = String.Empty;
            var ver = "";
            var asm = Assembly.GetEntryAssembly();
            if (asm != null)
            {
                if (String.IsNullOrEmpty(name))
                {
                    var att = asm.GetCustomAttribute<AssemblyTitleAttribute>();
                    if (att != null) name = att.Title;
                }

                if (String.IsNullOrEmpty(name))
                {
                    var att = asm.GetCustomAttribute<AssemblyProductAttribute>();
                    if (att != null) name = att.Product;
                }

                if (String.IsNullOrEmpty(name))
                {
                    var att = asm.GetCustomAttribute<AssemblyDescriptionAttribute>();
                    if (att != null) name = att.Description;
                }

                var tar = asm.GetCustomAttribute<System.Runtime.Versioning.TargetFrameworkAttribute>();
                if (tar != null) ver = tar.FrameworkDisplayName ?? tar.FrameworkName;
            }
#if __CORE__
            ver = RuntimeInformation.FrameworkDescription;
#endif
            if (String.IsNullOrEmpty(name))
            {
                try
                {
                    name = process.ProcessName;
                }
                catch { }
            }
            var sb = new StringBuilder();
            sb.AppendFormat("#Software: {0}\r\n", name);
            sb.AppendFormat("#ProcessID: {0}{1}\r\n", process.Id, Environment.Is64BitProcess ? " x64" : "");
            sb.AppendFormat("#AppDomain: {0}\r\n", AppDomain.CurrentDomain.FriendlyName);

            var fileName = String.Empty;
            // MonoAndroid无法识别MainModule，致命异常
            try
            {
                fileName = process.MainModule.FileName;
            }
            catch { }
            if (fileName.IsNullOrEmpty() || !fileName.EndsWithIgnoreCase("dotnet", "dotnet.exe"))
            {
                try
                {
                    fileName = process.StartInfo.FileName;
                }
                catch { }
            }
            if (!fileName.IsNullOrEmpty()) sb.AppendFormat("#FileName: {0}\r\n", fileName);

            // 应用域目录
            var baseDir = AppDomain.CurrentDomain.BaseDirectory;
            sb.AppendFormat("#BaseDirectory: {0}\r\n", baseDir);

            // 当前目录。如果由别的进程启动，默认的当前目录就是父级进程的当前目录
            var curDir = System.Environment.CurrentDirectory;
            //if (!curDir.EqualIC(baseDir) && !(curDir + "\\").EqualIC(baseDir))
            if (!baseDir.EqualIgnoreCase(curDir, curDir + "\\", curDir + "/"))
                sb.AppendFormat("#CurrentDirectory: {0}\r\n", curDir);

            // 命令行不为空，也不是文件名时，才输出
            // 当使用cmd启动程序时，这里就是用户输入的整个命令行，所以可能包含空格和各种符号
            var line = System.Environment.CommandLine;
            if (!line.IsNullOrEmpty())
                sb.AppendFormat("#CommandLine: {0}\r\n", line);

            var apptype = "";
            if (Runtime.IsWeb)
                apptype = "Web";
            else if (!Environment.UserInteractive)
                apptype = "Service";
            else if (Runtime.IsConsole)
                apptype = "Console";
            else
                apptype = "WinForm";

            sb.AppendFormat("#ApplicationType: {0}\r\n", apptype);
            sb.AppendFormat("#CLR: {0}, {1}\r\n", Environment.Version, ver);

            var os = "";
            // 获取丰富的机器信息，需要提注册 MachineInfo.RegisterAsync
            var mi = MachineInfo.Current;
            if (mi != null)
            {
                os = mi.OSName + " " + mi.OSVersion;
            }
            else
            {
                // 特别识别Linux发行版
                os = Environment.OSVersion + "";
                if (Runtime.Linux) os = MachineInfo.GetLinuxName();
            }

            sb.AppendFormat("#OS: {0}, {1}/{2}\r\n", os, Environment.MachineName, Environment.UserName);
            sb.AppendFormat("#CPU: {0}\r\n", Environment.ProcessorCount);
            if (mi != null)
            {
                sb.AppendFormat("#Memory: {0:n0}M/{1:n0}M\r\n", mi.AvailableMemory / 1024 / 1024, mi.Memory / 1024 / 1024);
                sb.AppendFormat("#Processor: {0}\r\n", mi.Processor);
                if (mi.Temperature > 0) sb.AppendFormat("#Temperature: {0}\r\n", mi.Temperature);
            }
            sb.AppendFormat("#GC: IsServerGC={0}, LatencyMode={1}\r\n", GCSettings.IsServerGC, GCSettings.LatencyMode);

            sb.AppendFormat("#Date: {0:yyyy-MM-dd}\r\n", DateTime.Now);
            sb.AppendFormat("#字段: 时间 线程ID 线程池Y网页W普通N 线程名 消息内容\r\n");
            sb.AppendFormat("#Fields: Time ThreadID IsPoolThread ThreadName Message\r\n");

            return sb.ToString();
        }
        #endregion
    }
}