/**
 * @file mcp_logger.h
 * @brief 简单的日志记录机制
 */

#ifndef MCP_LOGGER_H
#define MCP_LOGGER_H

#include <iostream>
#include <sstream>
#include <string>
#include <mutex>
#include <chrono>
#include <iomanip>

namespace mcp {

enum class log_level {
    debug,
    info,
    warning,
    error
};

class logger {
public:
    static logger& instance() {
        static logger instance;
        return instance;
    }
    
    void set_level(log_level level) {
        std::lock_guard<std::mutex> lock(mutex_);
        level_ = level;
    }
    
    template<typename... Args>
    void debug(Args&&... args) {
        log(log_level::debug, std::forward<Args>(args)...);
    }
    
    template<typename... Args>
    void info(Args&&... args) {
        log(log_level::info, std::forward<Args>(args)...);
    }
    
    template<typename... Args>
    void warning(Args&&... args) {
        log(log_level::warning, std::forward<Args>(args)...);
    }
    
    template<typename... Args>
    void error(Args&&... args) {
        log(log_level::error, std::forward<Args>(args)...);
    }
    
private:
    logger() : level_(log_level::info) {}
    
    template<typename T>
    void log_impl(std::stringstream& ss, T&& arg) {
        ss << std::forward<T>(arg);
    }
    
    template<typename T, typename... Args>
    void log_impl(std::stringstream& ss, T&& arg, Args&&... args) {
        ss << std::forward<T>(arg);
        log_impl(ss, std::forward<Args>(args)...);
    }
    
    template<typename... Args>
    void log(log_level level, Args&&... args) {
        if (level < level_) {
            return;
        }
        
        std::stringstream ss;
        
        // 添加时间戳
        auto now = std::chrono::system_clock::now();
        auto now_c = std::chrono::system_clock::to_time_t(now);
        auto now_tm = std::localtime(&now_c);
        
        ss << std::put_time(now_tm, "%Y-%m-%d %H:%M:%S") << " ";
        
        // 添加日志级别
        switch (level) {
            case log_level::debug:
                ss << "[DEBUG] ";
                break;
            case log_level::info:
                ss << "[INFO] ";
                break;
            case log_level::warning:
                ss << "[WARNING] ";
                break;
            case log_level::error:
                ss << "[ERROR] ";
                break;
        }
        
        // 添加日志内容
        log_impl(ss, std::forward<Args>(args)...);
        
        // 输出日志
        std::lock_guard<std::mutex> lock(mutex_);
        std::cerr << ss.str() << std::endl;
    }
    
    log_level level_;
    std::mutex mutex_;
};

#define LOG_DEBUG(...) mcp::logger::instance().debug(__VA_ARGS__)
#define LOG_INFO(...) mcp::logger::instance().info(__VA_ARGS__)
#define LOG_WARNING(...) mcp::logger::instance().warning(__VA_ARGS__)
#define LOG_ERROR(...) mcp::logger::instance().error(__VA_ARGS__)

} // namespace mcp

#endif // MCP_LOGGER_H