using Godot;
using System;
using System.Collections.Generic;
using System.Diagnostics;

/// <summary>
/// 仿照 Python logging 的 日志系统
/// </summary>
public static class Logging {
    // ========== 日志级别 ==========
    public enum Level {
        NOSET = 0,
        DEBUG = 10,
        INFO = 20,
        WARNING = 30,
        ERROR = 40,
        CRITICAL = 50
    }

    /// <summary>
    /// 日志记录器
    /// </summary>
    public class Logger(string name) {
        public string Name { get; } = name;
        public Level LogLevel { get; set; } = Level.INFO;
        private readonly List<Action<Level, string, string, string>> _handlers = [];

        public void AddHandler(Action<Level, string, string, string> handler) =>
            _handlers.Add(handler);

        // ===== 日志方法 =====
        public void Debug(string fmt, params object[] args) =>
            Log(Level.DEBUG, fmt, false, args);

        public void Info(string fmt, params object[] args) =>
            Log(Level.INFO, fmt, false, args);

        public void Warning(string fmt, params object[] args) =>
            Log(Level.WARNING, fmt, false, args);

        public void Error(string fmt, params object[] args) =>
            Log(Level.ERROR, fmt, false, args);

        public void Critical(string fmt, params object[] args) =>
            Log(Level.CRITICAL, fmt, true, args);

        public void Exception(string fmt, Exception e, params object[] args) {
            // TODO for godot not support /r/n yet
            string stackTrace = e.StackTrace?.Replace("\r\n", "\n") ?? "";
            string exceptionMessage = $"{fmt}\n{e.Message}\n{stackTrace}";

            Log(Level.ERROR, exceptionMessage, false, args);
        }

        // ===== 核心Log方法 =====
        private void Log(Level level, string fmt, bool isExec = false, params object[] args) {
            if (level < LogLevel) return;

            // 格式化消息
            string message = args.Length > 0 ?
                string.Format(fmt, args) : fmt;

            // 添加执行堆栈信息
            string stackInfo = isExec ?
                $"\nExecution Stack:\n{System.Environment.StackTrace}" : "";

            // 构建前缀
            string prefix = $"[{DateTime.Now:HH:mm:ss}] [{level}] [{Name}]";

            // 调用所有处理器
            foreach (var handler in _handlers) {
                handler(level, prefix, message, stackInfo);
            }
        }

        [Conditional("DEBUG")]
        public void Assert(bool condition, string fmt, params object[] args) {
            if (condition) return;
            string message = args.Length > 0 ?
                string.Format(fmt, args) : fmt;
            Error("Assertion Failed: " + message, true);

            if (Debugger.IsAttached)
                Debugger.Break();

            System.Diagnostics.Debug.Assert(condition, message);
        }
    }

    // ========== 全局管理器 ==========
    private static readonly Dictionary<string, Logger> _loggers = [];
    private static readonly Logger _root = GetLogger("root");

    /// <summary>
    /// 获取或创建日志记录器
    /// </summary>
    public static Logger GetLogger(string name = "root") {
        if (!_loggers.TryGetValue(name, out var logger)) {
            logger = new Logger(name);
            logger.AddHandler(DefaultHandler);
            _loggers[name] = logger;
        }
        return logger;
    }

    // ========== 优化的默认处理器 ==========
    private static void DefaultHandler(Level level, string prefix, string message, string stackInfo) {
        // 构建完整日志消息
        string fullMessage = $"{prefix} {message}{stackInfo}";

        switch (level) {
            case Level.DEBUG:
                // DEBUG级别：使用GD.Print + OS条件
                if (OS.IsStdOutVerbose())
                    GD.Print(fullMessage);
                break;

            case Level.INFO:
                // INFO级别：使用GD.Print
                GD.Print(fullMessage);
                break;

            case Level.WARNING:
                // WARNING级别：使用PrintRich + 黄色
                GD.PrintRich($"[color=yellow]{fullMessage}[/color]");
                break;

            case Level.ERROR:
                // ERROR级别：使用GD.PrintErr
                GD.PrintRich($"[color=red][b]{fullMessage}[/b][/color]");
                // GD.PrintErr(fullMessage);
                break;

            case Level.CRITICAL:
                // CRITICAL级别：使用GD.PushError
                GD.PushError(fullMessage);
                break;
        }
    }

    // ========== 快捷操作方式 ==========
    public static void Debug(string fmt, params object[] args) =>
        _root.Debug(fmt, args);

    public static void Info(string fmt, params object[] args) =>
        _root.Info(fmt, args);

    public static void Warning(string fmt, params object[] args) =>
        _root.Warning(fmt, args);

    public static void Error(string fmt, params object[] args) =>
        _root.Error(fmt, args);

    public static void Critical(string fmt, params object[] args) =>
        _root.Critical(fmt, args);

    // ===== C语言风格的宏断言快捷方式 =====
    [Conditional("DEBUG")]
    public static void Assert(bool condition, string fmt, params object[] args) =>
        _root.Assert(condition, fmt, args);

    [Conditional("DEBUG")]
    public static void TestPrint() {
        GD.Print("GameSystem Singleton Initialized");
        GD.PrintErr("This is a print error");
        GD.PushWarning("This is a warning");
        GD.PushError("This is a error");
        Debug("This is a debug");
        Info("This is a info");
        Warning("This is a warn");
        Error("This is a error");
        Critical("This is a critical");
        Assert(true, "This is a assert");
    }
}