/*
 *  The Mana Server
 *  Copyright (C) 2006-2010  The Mana World Development Team
 *
 *  This file is part of The Mana Server.
 *
 *  The Mana Server 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
 *  any later version.
 *
 *  The Mana Server 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 The Mana Server.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "game-server/accountconnection.h"

#include "common/configuration.h"
#include "common/defines.h"
#include "game-server/being.h"
#include "game-server/charactercomponent.h"
#include "game-server/gamehandler.h"
#include "game-server/mapcomposite.h"
#include "game-server/mapmanager.h"
#include "game-server/item.h"
#include "game-server/itemmanager.h"
#include "game-server/postman.h"
#include "game-server/quest.h"
#include "game-server/state.h"
#include "net/messagein.h"
#include "utils/logger.h"
#include "utils/tokendispenser.h"

/** Maximum size of sync buffer in bytes. */
const unsigned SYNC_BUFFER_SIZE = 1024;

/** Maximum number of messages in sync buffer. */
const int SYNC_BUFFER_LIMIT = 20;

AccountConnection::AccountConnection():
    mSyncBuffer(nullptr),
    mSyncMessages(0)
{
}

AccountConnection::~AccountConnection()
{
    delete mSyncBuffer;
}

bool AccountConnection::start(int gameServerPort)
{
    const std::string accountServerAddress =
            Configuration::getValue("net_accountListenToGameHost",
                                    Configuration::getValue("net_accountHost", "localhost"));

    // When the accountListenToGamePort is set, we use it.
    // Otherwise, we use the accountListenToClientPort + 1 if the option is set.
    // If neither, the DEFAULT_SERVER_PORT + 1 is used.
    int alternativePort =
        Configuration::getValue("net_accountListenToClientPort", 0) + 1;
    if (alternativePort == 1)
        alternativePort = DEFAULT_SERVER_PORT + 1;
    const int accountServerPort =
        Configuration::getValue("net_accountListenToGamePort", alternativePort);

    if (!Connection::start(accountServerAddress, accountServerPort))
    {
        LOG_INFO("Unable to create a connection to an account server.");
        return false;
    }

    LOG_INFO("Connection established to the account server.");

    const std::string gameServerName =
        Configuration::getValue("net_gameServerName", std::string());
    const std::string gameServerAddress =
        Configuration::getValue("net_publicGameHost",
                                Configuration::getValue("net_gameHost",
                                                        "localhost"));
    const std::string password =
        Configuration::getValue("net_password", "changeMe");

    // Register with the account server
    MessageOut msg(GAMSG_REGISTER);
    msg.writeString(gameServerName);
    msg.writeString(gameServerAddress);
    msg.writeInt16(gameServerPort);
    msg.writeString(password);
    msg.writeInt32(itemManager->getDatabaseVersion());
    send(msg);

    // initialize sync buffer
    if (!mSyncBuffer)
        mSyncBuffer = new MessageOut(GAMSG_PLAYER_SYNC);

    return true;
}

void AccountConnection::sendCharacterData(Entity *p)
{
    MessageOut msg(GAMSG_PLAYER_DATA);
    auto *characterComponent = p->getComponent<CharacterComponent>();
    msg.writeInt32(characterComponent->getDatabaseID());
    characterComponent->serialize(*p, msg);
    send(msg);
}

void AccountConnection::processMessage(MessageIn &msg)
{
    LOG_DEBUG("Received message " << msg << " from account server");

    switch (msg.getId())
    {
        case AGMSG_REGISTER_RESPONSE:
        {
            if (msg.readInt16() != DATA_VERSION_OK)
            {
                LOG_ERROR("Item database is outdated! Please update to "
                          "prevent inconsistencies");
                stop();  // Disconnect gracefully from account server.
                // Stop gameserver to prevent inconsistencies.
                exit(EXIT_DB_EXCEPTION);
            }
            else
            {
                LOG_DEBUG("Local item database is "
                          "in sync with account server.");
            }
            if (msg.readInt16() != PASSWORD_OK)
            {
                LOG_ERROR("This game server sent a invalid password");
                stop();
                exit(EXIT_BAD_CONFIG_PARAMETER);
            }

            // read world state variables
            while (msg.getUnreadLength())
            {
                std::string key = msg.readString();
                std::string value = msg.readString();
                if (!key.empty() && !value.empty())
                {
                    GameState::setVariableFromDbserver(key, value);
                }
            }

        } break;

        case AGMSG_PLAYER_ENTER:
        {
            std::string token = msg.readString(MAGIC_TOKEN_LENGTH);
            auto character = new Entity(OBJECT_CHARACTER);
            character->addComponent(new ActorComponent(*character));
            character->addComponent(new BeingComponent(*character));
            character->addComponent(new CharacterComponent(*character, msg));
            gameHandler->addPendingCharacter(token, character);
        } break;

        case AGMSG_ACTIVE_MAP:
        {
            int mapId = msg.readInt16();
            if (MapManager::activateMap(mapId))
            {
                // Set map variables
                MapComposite *m = MapManager::getMap(mapId);
                int mapVarsNumber = msg.readInt16();
                for(int i = 0; i < mapVarsNumber; ++i)
                {
                    std::string key = msg.readString();
                    std::string value = msg.readString();
                    if (!key.empty() && !value.empty())
                        m->setVariableFromDbserver(key, value);
                }

                // Recreate potential persistent floor items
                LOG_DEBUG("Recreate persistant items on map " << mapId);
                int floorItemsNumber = msg.readInt16();

                for (int i = 0; i < floorItemsNumber; ++i)
                {
                    int itemId = msg.readInt32();
                    int amount = msg.readInt16();
                    int posX = msg.readInt16();
                    int posY = msg.readInt16();

                    if (ItemClass *ic = itemManager->getItem(itemId))
                    {
                        Entity *item = Item::create(m,
                                                    Point(posX, posY),
                                                    ic, amount);

                        if (!GameState::insertOrDelete(item))
                        {
                            // The map is full.
                            LOG_WARN("Couldn't add floor item(s) " << itemId
                                     << " into map " << mapId);
                            return;
                        }
                    }
                }
            }
        } break;

        case AGMSG_SET_VAR_WORLD:
        {
            std::string key = msg.readString();
            std::string value = msg.readString();
            GameState::setVariableFromDbserver(key, value);
            LOG_DEBUG("Global variable \"" << key << "\" has changed to \""
                      << value << "\"");
        } break;

        case AGMSG_REDIRECT_RESPONSE:
        {
            int id = msg.readInt32();
            std::string token = msg.readString(MAGIC_TOKEN_LENGTH);
            std::string address = msg.readString();
            int port = msg.readInt16();
            gameHandler->completeServerChange(id, token, address, port);
        } break;

        case AGMSG_GET_VAR_CHR_RESPONSE:
        {
            int id = msg.readInt32();
            std::string name = msg.readString();
            std::string value = msg.readString();
            recoveredQuestVar(id, name, value);
        } break;

        case CGMSG_CHANGED_PARTY:
        {
            // Character DB id
            int charid = msg.readInt32();
            // Party id, 0 for none
            int partyid = msg.readInt32();
            gameHandler->updateCharacter(charid, partyid);
        } break;

        case CGMSG_POST_RESPONSE:
        {
            // get the character
            Entity  *character = postMan->getCharacter(msg.readInt32());

            // check character is still valid
            if (!character)
            {
                break;
            }

            std::string sender = msg.readString();
            std::string letter = msg.readString();

            postMan->gotPost(character, sender, letter);

        } break;

        case CGMSG_STORE_POST_RESPONSE:
        {
            // get character
            Entity *character = postMan->getCharacter(msg.readInt32());

            // check character is valid
            if (!character)
            {
                break;
            }

            // TODO: Get NPC to tell character if the sending of post
            // was successful or not

        } break;

        default:
            LOG_WARN("Invalid message type");
            break;
    }
}

void AccountConnection::playerReconnectAccount(int id,
                                               const std::string &magic_token)
{
    LOG_DEBUG("Send GAMSG_PLAYER_RECONNECT.");
    MessageOut msg(GAMSG_PLAYER_RECONNECT);
    msg.writeInt32(id);
    msg.writeString(magic_token, MAGIC_TOKEN_LENGTH);
    send(msg);
}

void AccountConnection::requestCharacterVar(Entity *ch,
                                            const std::string &name)
{
    MessageOut msg(GAMSG_GET_VAR_CHR);
    msg.writeInt32(ch->getComponent<CharacterComponent>()->getDatabaseID());
    msg.writeString(name);
    send(msg);
}

void AccountConnection::updateCharacterVar(Entity *ch,
                                           const std::string &name,
                                           const std::string &value)
{
    MessageOut msg(GAMSG_SET_VAR_CHR);
    msg.writeInt32(ch->getComponent<CharacterComponent>()->getDatabaseID());
    msg.writeString(name);
    msg.writeString(value);
    send(msg);
}

void AccountConnection::updateMapVar(MapComposite *map,
                                     const std::string &name,
                                     const std::string &value)
{
    MessageOut msg(GAMSG_SET_VAR_MAP);
    msg.writeInt32(map->getID());
    msg.writeString(name);
    msg.writeString(value);
    send(msg);
}

void AccountConnection::updateWorldVar(const std::string &name,
                                       const std::string &value)
{
    MessageOut msg(GAMSG_SET_VAR_WORLD);
    msg.writeString(name);
    msg.writeString(value);
    send(msg);
}

void AccountConnection::banCharacter(Entity *ch, int duration)
{
    MessageOut msg(GAMSG_BAN_PLAYER);
    msg.writeInt32(ch->getComponent<CharacterComponent>()->getDatabaseID());
    msg.writeInt32(duration);
    send(msg);
}

void AccountConnection::sendStatistics()
{
    MessageOut msg(GAMSG_STATISTICS);
    const MapManager::Maps &maps = MapManager::getMaps();
    for (auto map : maps)
    {
        MapComposite *m = map.second;
        if (!m->isActive()) continue;
        msg.writeInt16(map.first);
        int nbEntities = 0, nbMonsters = 0;
        using Entities = std::vector<Entity *>;
        const Entities &things = m->getEverything();
        std::vector< int > players;
        for (auto t : things)
        {
            switch (t->getType())
            {
                case OBJECT_CHARACTER:
                {
                    auto *characterComponent =
                            t->getComponent<CharacterComponent>();
                    players.push_back(characterComponent->getDatabaseID());
                    break;
                }
                case OBJECT_MONSTER:
                    ++nbMonsters;
                    break;
                default:
                    ++nbEntities;
            }
        }
        msg.writeInt16(nbEntities);
        msg.writeInt16(nbMonsters);
        msg.writeInt16(players.size());
        for (int player : players)
        {
            msg.writeInt32(player);
        }
    }
    send(msg);
}

void AccountConnection::sendPost(Entity *c, MessageIn &msg)
{
    // send message to account server with id of sending player,
    // the id of receiving player, the letter receiver and contents, and attachments
    LOG_DEBUG("Sending GCMSG_STORE_POST.");
    MessageOut out(GCMSG_STORE_POST);
    out.writeInt32(c->getComponent<CharacterComponent>()->getDatabaseID());
    out.writeString(msg.readString()); // name of receiver
    out.writeString(msg.readString()); // content of letter
    while (msg.getUnreadLength()) // attachments
    {
        // write the item id and amount for each attachment
        out.writeInt32(msg.readInt16());
        out.writeInt32(msg.readInt16());
    }
    send(out);
}

void AccountConnection::getPost(Entity *c)
{
    // let the postman know to expect some post for this character
    postMan->addCharacter(c);

    // send message to account server with id of retrieving player
    LOG_DEBUG("Sending GCMSG_REQUEST_POST");
    MessageOut out(GCMSG_REQUEST_POST);
    out.writeInt32(c->getComponent<CharacterComponent>()->getDatabaseID());
    send(out);
}

void AccountConnection::changeAccountLevel(Entity *c, int level)
{
    MessageOut msg(GAMSG_CHANGE_ACCOUNT_LEVEL);
    msg.writeInt32(c->getComponent<CharacterComponent>()->getDatabaseID());
    msg.writeInt16(level);
    send(msg);
}

void AccountConnection::syncChanges(bool force)
{
    if (mSyncMessages == 0)
        return;

    // send buffer if:
    //    a.) forced by any process
    //    b.) every 10 seconds
    //    c.) buffer reaches size of 1kb
    //    d.) buffer holds more then 20 messages
    if (force ||
        mSyncMessages > SYNC_BUFFER_LIMIT ||
        mSyncBuffer->getLength() > SYNC_BUFFER_SIZE )
    {
        LOG_DEBUG("Sending GAMSG_PLAYER_SYNC with "
                << mSyncMessages << " messages." );

        send(*mSyncBuffer);
        delete mSyncBuffer;

        mSyncBuffer = new MessageOut(GAMSG_PLAYER_SYNC);
        mSyncMessages = 0;
    }
    else
    {
        LOG_DEBUG("No changes to sync with account server.");
    }
}

void AccountConnection::updateCharacterPoints(int charId, int charPoints,
                                              int corrPoints)
{
    ++mSyncMessages;
    mSyncBuffer->writeInt8(SYNC_CHARACTER_POINTS);
    mSyncBuffer->writeInt32(charId);
    mSyncBuffer->writeInt32(charPoints);
    mSyncBuffer->writeInt32(corrPoints);
    syncChanges();
}

void AccountConnection::updateAttributes(int charId, int attrId, double base,
                                         double mod)
{
    ++mSyncMessages;
    mSyncBuffer->writeInt8(SYNC_CHARACTER_ATTRIBUTE);
    mSyncBuffer->writeInt32(charId);
    mSyncBuffer->writeInt32(attrId);
    mSyncBuffer->writeDouble(base);
    mSyncBuffer->writeDouble(mod);
    syncChanges();
}

void AccountConnection::updateOnlineStatus(int charId, bool online)
{
    ++mSyncMessages;
    mSyncBuffer->writeInt8(SYNC_ONLINE_STATUS);
    mSyncBuffer->writeInt32(charId);
    mSyncBuffer->writeInt8(online ? 1 : 0);
    syncChanges();
}

void AccountConnection::sendTransaction(int id, int action, const std::string &message)
{
    MessageOut msg(GAMSG_TRANSACTION);
    msg.writeInt32(id);
    msg.writeInt32(action);
    msg.writeString(message);
    send(msg);
}

void AccountConnection::createFloorItems(int mapId, int itemId, int amount,
                                         int posX, int posY)
{
    MessageOut msg(GAMSG_CREATE_ITEM_ON_MAP);
    msg.writeInt32(mapId);
    msg.writeInt32(itemId);
    msg.writeInt16(amount);
    msg.writeInt16(posX);
    msg.writeInt16(posY);
    send(msg);
}

void AccountConnection::removeFloorItems(int mapId, int itemId, int amount,
                                         int posX, int posY)
{
    MessageOut msg(GAMSG_REMOVE_ITEM_ON_MAP);
    msg.writeInt32(mapId);
    msg.writeInt32(itemId);
    msg.writeInt16(amount);
    msg.writeInt16(posX);
    msg.writeInt16(posY);
    send(msg);
}