/*
 * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 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 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 APPENDER_H
#define APPENDER_H

#include <unordered_map>
#include <stdexcept>
#include <string>
#include <time.h>
#include <type_traits>
#include <vector>
#include <utility>
#include "Define.h"

// Values assigned have their equivalent in enum ACE_Log_Priority
enum LogLevel
{
    LOG_LEVEL_DISABLED                           = 0,
    LOG_LEVEL_TRACE                              = 1,
    LOG_LEVEL_DEBUG                              = 2,
    LOG_LEVEL_INFO                               = 3,
    LOG_LEVEL_WARN                               = 4,
    LOG_LEVEL_ERROR                              = 5,
    LOG_LEVEL_FATAL                              = 6
};

const uint8 MaxLogLevels = 6;

enum AppenderType : uint8
{
    APPENDER_NONE,
    APPENDER_CONSOLE,
    APPENDER_FILE,
    APPENDER_DB
};

enum AppenderFlags
{
    APPENDER_FLAGS_NONE                          = 0x00,
    APPENDER_FLAGS_PREFIX_TIMESTAMP              = 0x01,
    APPENDER_FLAGS_PREFIX_LOGLEVEL               = 0x02,
    APPENDER_FLAGS_PREFIX_LOGFILTERTYPE          = 0x04,
    APPENDER_FLAGS_USE_TIMESTAMP                 = 0x08, // only used by FileAppender
    APPENDER_FLAGS_MAKE_FILE_BACKUP              = 0x10  // only used by FileAppender
};

struct TC_COMMON_API LogMessage
{
    LogMessage(LogLevel _level, std::string const& _type, std::string&& _text)
        : level(_level), type(_type), text(std::forward<std::string>(_text)), mtime(time(NULL))
    { }

    LogMessage(LogMessage const& /*other*/) = delete;
    LogMessage& operator=(LogMessage const& /*other*/) = delete;

    static std::string getTimeStr(time_t time);
    std::string getTimeStr();

    LogLevel const level;
    std::string const type;
    std::string const text;
    std::string prefix;
    std::string param1;
    time_t mtime;

    ///@ Returns size of the log message content in bytes
    uint32 Size() const
    {
        return static_cast<uint32>(prefix.size() + text.size());
    }
};

class TC_COMMON_API Appender
{
    public:
        Appender(uint8 _id, std::string const& name, LogLevel level = LOG_LEVEL_DISABLED, AppenderFlags flags = APPENDER_FLAGS_NONE);
        virtual ~Appender();

        uint8 getId() const;
        std::string const& getName() const;
        virtual AppenderType getType() const = 0;
        LogLevel getLogLevel() const;
        AppenderFlags getFlags() const;

        void setLogLevel(LogLevel);
        void write(LogMessage* message);
        static const char* getLogLevelString(LogLevel level);
        virtual void setRealmId(uint32 /*realmId*/) { }

    private:
        virtual void _write(LogMessage const* /*message*/) = 0;

        uint8 id;
        std::string name;
        LogLevel level;
        AppenderFlags flags;
};

typedef std::unordered_map<uint8, Appender*> AppenderMap;

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

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

class TC_COMMON_API InvalidAppenderArgsException : public std::length_error
{
public:
    explicit InvalidAppenderArgsException(std::string const& message) : std::length_error(message) { }
};

#endif