using System;
using System.Globalization;
using System.Text;

namespace TeamAAS
{
    /// <summary>
    /// 统一的进程内日志入口（底层经 NLog 写文件，见 TeamAAS.Logging.NLogHub）。
    /// 日志写入 CommonPattern 解析出的公共日志文件（如 Logs/年/年-月-日.log），与插件 1/2 级日志共用；
    /// 单文件大小归档与保留天数自动删除均由 NLog 原生完成（配置见 PluginLogConfig）。
    /// 写日志失败不会反向影响业务流程，只会回退到 Debug 输出，避免异常处理路径再次抛出异常。
    /// </summary>
    public static class AppLogger
    {
        /// <summary>是否启用文件日志。</summary>
        public static bool Enabled { get; set; } = true;

        /// <summary>低于该级别的日志不会写入文件。</summary>
        public static LogLevel MinimumLevel { get; set; } = LogLevel.Info;

        public static void Info(string message, string source = null) => Write(LogLevel.Info, message, null, source);
        public static void Warning(string message, string source = null) => Write(LogLevel.Warning, message, null, source);
        public static void Error(string message, string source = null) => Write(LogLevel.Error, message, null, source);
        public static void Error(string message, Exception exception, string source = null) => Write(LogLevel.Error, message, exception, source);

        /// <summary>
        /// 写入一条日志。该方法刻意不向调用方抛出异常，适合在 catch/finally 中使用。
        /// </summary>
        public static void Write(LogLevel level, string message, Exception exception = null, string source = null)
        {
            if (!Enabled || level < MinimumLevel)
                return;

            var now = DateTime.Now;
            var safeMessage = message ?? string.Empty;
            var builder = new StringBuilder();
            builder.Append(now.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture));
            builder.Append(" [").Append(level.ToString().ToUpperInvariant()).Append("]");
            builder.Append(" [T").Append(Environment.CurrentManagedThreadId).Append("]");
            if (!string.IsNullOrWhiteSpace(source))
                builder.Append(" [").Append(source.Trim()).Append("]");
            builder.Append(' ').Append(safeMessage.Replace(Environment.NewLine, " | "));

            if (exception != null)
            {
                builder.Append(" | ").Append(exception.GetType().FullName);
                builder.Append(": ").Append(exception.Message);
                if (!string.IsNullOrWhiteSpace(exception.StackTrace))
                    builder.AppendLine().Append(exception.StackTrace);
            }

            var line = builder.ToString();
            try
            {
                TeamAAS.Logging.NLogHub.Apply();
                TeamAAS.Logging.NLogHub.Common.Log(MapLevel(level), line);
            }
            catch (Exception loggingException)
            {
                System.Diagnostics.Debug.WriteLine("[TeamAAS logging failure] " + loggingException.Message);
                System.Diagnostics.Debug.WriteLine(line);
            }

            // 联动实时日志控件：公共日志条目（已受 Enabled/MinimumLevel 过滤），恒显示
            TeamAAS.Logging.LogStream.Publish(new TeamAAS.Logging.LogEntry(
                now, TeamAAS.Logging.LogSource.Common, level,
                sourceTag: source,
                message: exception == null ? safeMessage : safeMessage + " | " + exception.Message));
        }

        private static NLog.LogLevel MapLevel(LogLevel level)
        {
            switch (level)
            {
                case LogLevel.Warning: return NLog.LogLevel.Warn;
                case LogLevel.Error: return NLog.LogLevel.Error;
                default: return NLog.LogLevel.Info;
            }
        }
    }

    /// <summary>
    /// 日志类别（精简为三档），数值越大代表严重程度越高。
    /// </summary>
    public enum LogLevel
    {
        Info = 0,
        Warning = 1,
        Error = 2
    }
}