/*
 * This file is part of the AzerothCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation; either version 3 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _LOG_H__
#define _LOG_H__

#include "IoContext.h"
#include "Define.h"
#include "LogCommon.h"
#include "StringFormat.h"
#include <unordered_map>
#include <vector>
#include <memory>

class Appender;
class Logger;
struct LogMessage;

namespace Acore::Asio
{
    class IoContext;
    class Strand;
}

#define LOGGER_ROOT "root"

typedef Appender*(*AppenderCreatorFn)(uint8 id, std::string const& name, LogLevel level, AppenderFlags flags, std::vector<std::string_view> const& extraArgs);

template <class AppenderImpl>
Appender* CreateAppender(uint8 id, std::string const& name, LogLevel level, AppenderFlags flags, std::vector<std::string_view> const& extraArgs)
{
    return new AppenderImpl(id, name, level, flags, extraArgs);
}

class Log
{
typedef std::unordered_map<std::string, Logger> LoggerMap;

private:
    Log();
    ~Log();
    Log(Log const&) = delete;
    Log(Log&&) = delete;
    Log& operator=(Log const&) = delete;
    Log& operator=(Log&&) = delete;

public:
    static Log* instance();

    void Initialize(Acore::Asio::IoContext* ioContext = nullptr);
    void SetSynchronous();  // Not threadsafe - should only be called from main() after all threads are joined
    void LoadFromConfig();
    void Close();
    [[nodiscard]] bool ShouldLog(std::string const& type, LogLevel level) const;
    bool SetLogLevel(std::string const& name, int32 level, bool isLogger = true);

    template<typename... Args>
    inline void outMessage(std::string const& filter, LogLevel const level, Acore::FormatString<Args...> fmt, Args&&... args)
    {
        _outMessage(filter, level, Acore::StringFormat(fmt, std::forward<Args>(args)...));
    }

    template<typename... Args>
    void outCommand(uint32 account, Acore::FormatString<Args...> fmt, Args&&... args)
    {
        if (!ShouldLog("commands.gm", LOG_LEVEL_INFO))
        {
            return;
        }

        _outCommand(Acore::StringFormat(fmt, std::forward<Args>(args)...), std::to_string(account));
    }

    void SetRealmId(uint32 id);

    template<class AppenderImpl>
    void RegisterAppender()
    {
        RegisterAppender(AppenderImpl::type, &CreateAppender<AppenderImpl>);
    }

    [[nodiscard]] std::string const& GetLogsDir() const { return m_logsDir; }
    [[nodiscard]] std::string const& GetLogsTimestamp() const { return m_logsTimestamp; }

private:
    static std::string GetTimestampStr();
    void write(std::unique_ptr<LogMessage>&& msg) const;

    [[nodiscard]] Logger const* GetLoggerByType(std::string const& type) const;
    Appender* GetAppenderByName(std::string_view name);
    uint8 NextAppenderId();
    void CreateAppenderFromConfig(std::string const& name);
    void CreateLoggerFromConfig(std::string const& name);
    void ReadAppendersFromConfig();
    void ReadLoggersFromConfig();
    void RegisterAppender(uint8 index, AppenderCreatorFn appenderCreateFn);
    void _outMessage(std::string const& filter, LogLevel level, std::string_view message);
    void _outCommand(std::string_view message, std::string_view param1);

    std::unordered_map<uint8, AppenderCreatorFn> appenderFactory;
    std::unordered_map<uint8, std::unique_ptr<Appender>> appenders;
    std::unordered_map<std::string, std::unique_ptr<Logger>> loggers;
    uint8 AppenderId;
    LogLevel highestLogLevel;

    std::string m_logsDir;
    std::string m_logsTimestamp;

    Acore::Asio::IoContext* _ioContext;
    std::unique_ptr<Acore::Asio::Strand> _strand;
};

#define sLog Log::instance()

#define LOG_EXCEPTION_FREE(filterType__, level__, ...) \
    { \
        try \
        { \
            sLog->outMessage(filterType__, level__, fmt::format(__VA_ARGS__)); \
        } \
        catch (std::exception const& e) \
        { \
            sLog->outMessage("server", LogLevel::LOG_LEVEL_ERROR, "Wrong format occurred ({}) at '{}:{}'", \
                e.what(), __FILE__, __LINE__); \
        } \
    }

#ifdef PERFORMANCE_PROFILING
#define LOG_MESSAGE_BODY(filterType__, level__, ...) ((void)0)
#else
#define LOG_MESSAGE_BODY(filterType__, level__, ...)                        \
        do                                                              \
        {                                                               \
            if (sLog->ShouldLog(filterType__, level__))                 \
                LOG_EXCEPTION_FREE(filterType__, level__, __VA_ARGS__); \
        } while (0)
#endif

// Fatal - 1
#define LOG_FATAL(filterType__, ...) \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_FATAL, __VA_ARGS__)

// Error - 2
#define LOG_ERROR(filterType__, ...) \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_ERROR, __VA_ARGS__)

// Warning - 3
#define LOG_WARN(filterType__, ...)  \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_WARN, __VA_ARGS__)

// Info - 4
#define LOG_INFO(filterType__, ...)  \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_INFO, __VA_ARGS__)

// Debug - 5
#define LOG_DEBUG(filterType__, ...) \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_DEBUG, __VA_ARGS__)

// Trace - 6
#define LOG_TRACE(filterType__, ...) \
    LOG_MESSAGE_BODY(filterType__, LogLevel::LOG_LEVEL_TRACE, __VA_ARGS__)

#define LOG_GM(accountId__, ...) \
    sLog->outCommand(accountId__, __VA_ARGS__)

#endif // _LOG_H__