/* Copyright (C) 2014 InfiniDB, Inc.
   Copyright (C) 2016 MariaDB Corporation

   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; version 2 of
   the License.

   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, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

#include <string>
//#define NDEBUG
#include <cassert>
#include <map>
#include <set>
using namespace std;

#include <boost/thread.hpp>
#include <boost/shared_ptr.hpp>
using namespace boost;

#define OAMCACHE_DLLEXPORT
#include "oamcache.h"
#undef OAMCACHE_DLLEXPORT
#include "liboamcpp.h"
#include "exceptclasses.h"
#include "configcpp.h"
#include "installdir.h"
#include "mcsconfig.h"

namespace
{
oam::OamCache* oamCache = 0;
boost::mutex cacheLock;
}

namespace oam
{

OamCache* OamCache::makeOamCache()
{
    boost::mutex::scoped_lock lk(cacheLock);

    if (oamCache == 0)
        oamCache = new OamCache();

    return oamCache;
}

OamCache::OamCache() : mtime(0), mLocalPMId(0)
{}

OamCache::~OamCache()
{}

void OamCache::checkReload()
{
    Oam oam;
    config::Config* config = config::Config::makeConfig();
    int temp;

    if (config->getCurrentMTime() == mtime)
        return;

    dbroots.clear();
    oam.getSystemDbrootConfig(dbroots);

    string txt = config->getConfig("SystemConfig", "DBRootCount");
    mtime = config->getLastMTime();   // get 'last' after the first access; quicker than 'current'
    idbassert(txt != "");
    numDBRoots = config->fromText(txt);

    dbRootPMMap.reset(new map<int, int>());

    //cout << "reloading oamcache\n";
    for (uint32_t i = 0; i < dbroots.size(); i++)
    {
        oam.getDbrootPmConfig(dbroots[i], temp);
        //cout << "  dbroot " << dbroots[i] << " -> PM " << temp << endl;
        (*dbRootPMMap)[dbroots[i]] = temp;
    }

    ModuleTypeConfig moduletypeconfig;
    std::set<int> uniquePids;
    oam.getSystemConfig("pm", moduletypeconfig);
    int moduleID = 0;

    for (unsigned i = 0; i < moduletypeconfig.ModuleCount; i++)
    {
        moduleID = atoi((moduletypeconfig.ModuleNetworkList[i]).DeviceName.substr(MAX_MODULE_TYPE_SIZE, MAX_MODULE_ID_SIZE).c_str());
        uniquePids.insert(moduleID);
    }

    std::set<int>::const_iterator it = uniquePids.begin();
    moduleIds.clear();
    uint32_t i = 0;
    map<int, int> pmToConnectionMap;
#ifdef _MSC_VER
    moduleIds.push_back(*it);
    pmToConnectionMap[*it] = i++;
#else

    // Restore for Windows when we support multiple PMs
    while (it != uniquePids.end())
    {
        // Disable legacy-OAM.
/*
        if (getenv("SKIP_OAM_INIT") == NULL)
        {
            try
            {
                int state = oam::MAN_INIT;
                bool degraded;
                char num[80];
                int retry = 0;

                // MCOL-259 retry for 5 seconds if the PM is in some INIT mode.
                while ((   state == oam::BUSY_INIT
                           || state == oam::MAN_INIT
                           || state == oam::PID_UPDATE)
                        && retry < 5)
                {
                    snprintf(num, 80, "%d", *it);

                    try
                    {
                        oam.getModuleStatus(string("pm") + num, state, degraded);
                    }
                    catch (std::exception& e)
                    {
                        ostringstream os;
                        os << "OamCache::checkReload exception while getModuleStatus pm" << num << " " << e.what();
                        oam.writeLog(os.str(), logging::LOG_TYPE_ERROR);
                        break;
                    }
                    catch (...)
                    {
                        ostringstream os;
                        os << "OamCache::checkReload exception while getModuleStatus pm" << num;
                        oam.writeLog(os.str(), logging::LOG_TYPE_ERROR);
                        break;
                    }

                    if (state == oam::ACTIVE || state == oam::DEGRADED)
                    {
                        pmToConnectionMap[*it] = i++;
                        moduleIds.push_back(*it);
                        break;
                    }

                    sleep(1);
                    ++retry;
                    //cout << "pm " << *it << " -> connection " << (i-1) << endl;
                }

                if (state != oam::ACTIVE)
                {
                    ostringstream os;
                    os << "OamCache::checkReload shows state for pm" << num << " as " << oamState[state];
                    oam.writeLog(os.str(), logging::LOG_TYPE_ERROR);
                }
            }
            catch (std::exception& e)
            {
                ostringstream os;
                os << "OamCache::checkReload final exception while getModuleStatus " << e.what();
                oam.writeLog(os.str(), logging::LOG_TYPE_ERROR);
                break;
            }
            catch (...)
            {
                ostringstream os;
                os << "OamCache::checkReload final exception while getModuleStatus";
                oam.writeLog(os.str(), logging::LOG_TYPE_ERROR);
                break;
            }
        }
        else
*/
        {
            pmToConnectionMap[*it] = i++;
            moduleIds.push_back(*it);
        }
        it++;

    }

#endif
    dbRootConnectionMap.reset(new map<int, int>());

    for (i = 0; i < dbroots.size(); i++)
    {
        map<int, int>::iterator pmIter = pmToConnectionMap.find((*dbRootPMMap)[dbroots[i]]);

        if (pmIter != pmToConnectionMap.end())
        {
            (*dbRootConnectionMap)[dbroots[i]] = (*pmIter).second;
        }
    }

    pmDbrootsMap.reset(new OamCache::PMDbrootsMap_t::element_type());
    systemStorageInfo_t t;
    t = oam.getStorageConfig();
    DeviceDBRootList moduledbrootlist = boost::get<2>(t);
    DeviceDBRootList::iterator pt = moduledbrootlist.begin();

    for ( ; pt != moduledbrootlist.end() ; pt++)
    {
        moduleID = (*pt).DeviceID;
        DBRootConfigList::iterator pt1 = (*pt).dbrootConfigList.begin();

        for ( ; pt1 != (*pt).dbrootConfigList.end(); pt1++)
        {
            (*pmDbrootsMap)[moduleID].push_back(*pt1);
        }
    }

    oamModuleInfo_t tm;
    tm = oam.getModuleInfo();
    OAMParentModuleName = boost::get<3>(tm);
    systemName = config->getConfig("SystemConfig", "SystemName");
}

OamCache::dbRootPMMap_t OamCache::getDBRootToPMMap()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return dbRootPMMap;
}

OamCache::dbRootPMMap_t OamCache::getDBRootToConnectionMap()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return dbRootConnectionMap;
}

OamCache::PMDbrootsMap_t OamCache::getPMToDbrootsMap()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return pmDbrootsMap;
}

uint32_t OamCache::getDBRootCount()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return numDBRoots;
}

DBRootConfigList& OamCache::getDBRootNums()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return dbroots;
}

std::vector<int>& OamCache::getModuleIds()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return moduleIds;
}

std::string OamCache::getOAMParentModuleName()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return OAMParentModuleName;
}

int OamCache::getLocalPMId()
{
    boost::mutex::scoped_lock lk(cacheLock);

    // This comes from the file /var/lib/columnstore/local/module, not from the xml.
    // Thus, it's not refreshed during checkReload().
    if (mLocalPMId > 0)
    {
        return mLocalPMId;
    }

    string localModule;
    string moduleType;
    string fileName = "/var/lib/columnstore/local/module";
    ifstream moduleFile (fileName.c_str());
    char line[400];

    while (moduleFile.getline(line, 400))
    {
        localModule = line;
        break;
    }

    moduleFile.close();

    if (localModule.empty() )
    {
        mLocalPMId = 0;
        return mLocalPMId;
    }

    moduleType = localModule.substr(0, MAX_MODULE_TYPE_SIZE);
    mLocalPMId = atoi(localModule.substr(MAX_MODULE_TYPE_SIZE, MAX_MODULE_ID_SIZE).c_str());

    if (moduleType != "pm")
    {
        mLocalPMId = 0;
    }

    return mLocalPMId;
}

string OamCache::getSystemName()
{
    boost::mutex::scoped_lock lk(cacheLock);

    checkReload();
    return systemName;
}

string OamCache::getModuleName()
{
    boost::mutex::scoped_lock lk(cacheLock);

    if (!moduleName.empty())
        return moduleName;

    string fileName = "/var/lib/columnstore/local/module";
    ifstream moduleFile(fileName.c_str());
    getline(moduleFile, moduleName);
    moduleFile.close();

    return moduleName;
}

} /* namespace oam */