#ifndef MODULAR_LOGGER_HPP
#define MODULAR_LOGGER_HPP

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

/// @brief Log severity levels.
enum class LogLevel {
    DEBUG, ///< Detailed debug information
    INFO,  ///< General informational messages
    WARN,  ///< Warning messages
    ERROR  ///< Error messages
};

/**
 * @brief Thread-safe logger with hierarchical level filtering.
 *
 * Provides logging at DEBUG, INFO, WARN, and ERROR levels.
 * Each log entry is prefixed with a timestamp and level tag.
 */
class Logger {
public:
    /**
     * @brief Construct a Logger with an optional minimum level.
     * @param level Minimum level to log (default: INFO).
     */
    explicit Logger(LogLevel level = LogLevel::INFO);

    /**
     * @brief Set the minimum log level.
     * @param level New minimum level.
     */
    void setLevel(LogLevel level);

    /**
     * @brief Get the current minimum log level.
     * @return Current LogLevel.
     */
    LogLevel level() const;

    /**
     * @brief Log a message at the given level.
     * @param level Severity level.
     * @param msg   Message text.
     *
     * If @p level is below the configured minimum, the message is discarded.
     */
    void log(LogLevel level, const std::string& msg);

    /// @brief Convenience: log at DEBUG level.
    void debug(const std::string& msg);
    /// @brief Convenience: log at INFO level.
    void info(const std::string& msg);
    /// @brief Convenience: log at WARN level.
    void warn(const std::string& msg);
    /// @brief Convenience: log at ERROR level.
    void error(const std::string& msg);

private:
    LogLevel level_;
    std::mutex mutex_;

    /// @brief Convert a LogLevel to its string representation.
    static std::string levelToString(LogLevel level);

    /// @brief Get current local time as a formatted string "[YYYY-MM-DD HH:MM:SS]".
    static std::string currentTimestamp();
};

#endif // MODULAR_LOGGER_HPP