/*
 * Copyright (C) 2005-2011 MaNGOS <http://getmangos.com/>
 * Copyright (C) 2009-2011 MaNGOSZero <https://github.com/mangos/zero>
 * Copyright (C) 2011-2016 Nostalrius <https://nostalrius.org>
 * Copyright (C) 2016-2017 Elysium Project <https://github.com/elysium-project>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "Util.h"
#include "DatabaseEnv.h"
#include "Config/Config.h"
#include "Database/SqlOperations.h"

#include <ctime>
#include <iostream>
#include <fstream>
#include <memory>

#define MIN_CONNECTION_POOL_SIZE 1
#define MAX_CONNECTION_POOL_SIZE 16

//////////////////////////////////////////////////////////////////////////
SqlPreparedStatement * SqlConnection::CreateStatement( const std::string& fmt )
{
 return new SqlPlainPreparedStatement(fmt, *this);
}

void SqlConnection::FreePreparedStatements()
{
 SqlConnection::Lock guard(this);

 size_t nStmts = m_holder.size();
 for (size_t i = 0; i < nStmts; ++i)
 delete m_holder[i];

 m_holder.clear();
}

SqlPreparedStatement * SqlConnection::GetStmt( int nIndex )
{
 if(nIndex < 0)
 return NULL;

 //resize stmt container
 if(m_holder.size() <= nIndex)
 m_holder.resize(nIndex + 1, NULL);

 SqlPreparedStatement * pStmt = NULL;

 //create stmt if needed
 if(m_holder[nIndex] == NULL)
 {
 //obtain SQL request string
 std::string fmt = m_db.GetStmtString(nIndex);
 MANGOS_ASSERT(fmt.length());
 //allocate SQlPreparedStatement object
 pStmt = CreateStatement(fmt);
 //prepare statement
 if(!pStmt->prepare())
 {
 //MANGOS_ASSERT(false && "Unable to prepare SQL statement");
 sLog.outError("Can't prepare %s, statement not executed!", fmt.c_str());
 return NULL;
 }

 //save statement in internal registry
 m_holder[nIndex] = pStmt;
 }
 else
 pStmt = m_holder[nIndex];

 return pStmt;
}

bool SqlConnection::Initialize(const char *infoString)
{
 Tokens tokens = StrSplit(infoString, ";");

 Tokens::iterator iter;

 iter = tokens.begin();

 m_use_socket = false;
 if (iter != tokens.end())
 {
 m_host = *iter++;
 if (m_host == ".")
 {
 m_host = "localhost";
 m_use_socket = true;
 }
 }
 if (iter != tokens.end())
 {
 m_port_or_socket = *iter++;
 m_port = atoi(m_port_or_socket.c_str());
 }
 if (iter != tokens.end())
 m_user = *iter++;
 if (iter != tokens.end())
 m_password = *iter++;
 if (iter != tokens.end())
 m_database = *iter++;

 return OpenConnection(false);
}

bool SqlConnection::ExecuteStmt(int nIndex, const SqlStmtParameters& id )
{
 if(nIndex == -1)
 return false;

 //get prepared statement object
 if (SqlPreparedStatement * pStmt = GetStmt(nIndex))
 {
 //bind parameters
 pStmt->bind(id);
 //execute statement
 return pStmt->execute();
 }
 return false;
}

//////////////////////////////////////////////////////////////////////////
Database::~Database()
{
 StopServer();
}

bool Database::Initialize(const char * infoString, int nConns /*= 1*/, int nWorkers)
{
 // Enable logging of SQL commands (usually only GM commands)
 // (See method: PExecuteLog)
 m_logSQL = sConfig.GetBoolDefault("LogSQL", false);
 m_logsDir = sConfig.GetStringDefault("LogsDir","");
 if(!m_logsDir.empty())
 {
 if((m_logsDir.at(m_logsDir.length()-1)!='/') && (m_logsDir.at(m_logsDir.length()-1)!='\\'))
 m_logsDir.append("/");
 }

 m_pingIntervallms = sConfig.GetIntDefault ("MaxPingTime", 30) * (MINUTE * 1000);

 //create DB connections

 //setup connection pool size
 if(nConns < MIN_CONNECTION_POOL_SIZE)
 m_nQueryConnPoolSize = MIN_CONNECTION_POOL_SIZE;
 else if(nConns > MAX_CONNECTION_POOL_SIZE)
 m_nQueryConnPoolSize = MAX_CONNECTION_POOL_SIZE;
 else
 m_nQueryConnPoolSize = nConns;

 //create connection pool for sync requests
 for (int i = 0; i < m_nQueryConnPoolSize; ++i)
 {
 SqlConnection * pConn = CreateConnection();
 if(!pConn->Initialize(infoString))
 {
 delete pConn;
 return false;
 }

 m_pQueryConnections.push_back(pConn);
 }

 //create and initialize connection for async requests
 m_pResultQueue = new SqlResultQueue;
 m_pAsyncConn = CreateConnection();
 if(!m_pAsyncConn->Initialize(infoString))
 return false;

 m_numAsyncWorkers = nWorkers;
 m_threadsBodies = new SqlDelayThread*[m_numAsyncWorkers];
 m_delayThreads = new ACE_Based::Thread*[m_numAsyncWorkers];
 m_serialDelayQueue = new SqlQueue*[m_numAsyncWorkers];
 for (int i = 0; i < nWorkers; ++i)
 if (!InitDelayThread(i, infoString))
 return false;

 return true;
}

void Database::StopServer()
{
 HaltDelayThread();

 /*Delete objects*/
 if (m_pResultQueue)
 {
 // Delete queued queries
 m_pResultQueue->CancelAll();
 delete m_pResultQueue;
 m_pResultQueue = NULL;
 }

 if (m_pAsyncConn)
 {
 delete m_pAsyncConn;
 m_pAsyncConn = NULL;
 }

 for (size_t i = 0; i < m_pQueryConnections.size(); ++i)
 delete m_pQueryConnections[i];

 m_pQueryConnections.clear();

}

bool Database::InitDelayThread(int i, std::string const& infoString)
{
 //New delay thread for delay execute

 SqlConnection* threadConnection = CreateConnection();
 if(!threadConnection->Initialize(infoString.c_str()))
 return false;
 m_threadsBodies[i] = new SqlDelayThread(this, threadConnection, i);
 m_threadsBodies[i]->incReference();
 m_delayThreads[i] = new ACE_Based::Thread(m_threadsBodies[i]);

 m_serialDelayQueue[i] = new SqlQueue();

 return true;
}

void Database::HaltDelayThread()
{
 if (!m_delayThreads || !m_threadsBodies)
 return;

 for (uint32 i = 0; i < m_numAsyncWorkers; ++i)
 {
 m_threadsBodies[i]->Stop();
 m_delayThreads[i]->wait();
 delete m_delayThreads[i];
 m_threadsBodies[i]->decReference();
 }
 delete[] m_threadsBodies;
 delete[] m_delayThreads;
 if (m_serialDelayQueue)
 delete[] m_serialDelayQueue;
 m_delayThreads = NULL;
 m_threadsBodies = NULL;
 m_serialDelayQueue = NULL;
 m_numAsyncWorkers = 0;
}

void Database::ThreadStart()
{
}

void Database::ThreadEnd()
{
}

void Database::ProcessResultQueue(uint32 maxTime)
{
 if (m_pResultQueue)
 m_pResultQueue->Update(maxTime);
}

void Database::escape_string(std::string& str)
{
 if (str.empty())
 return;

 int bufSize = str.size() * 2 + 1;
 char* buf = new char[bufSize + 1];
 //we don't care what connection to use - escape string will be the same
 m_pQueryConnections[0]->escape_string(buf, str.c_str(), str.size());
 buf[bufSize] = 0;
 str = buf;
 delete[] buf;
}

SqlConnection * Database::getQueryConnection()
{
 int nCount = 0;

 if(m_nQueryCounter == long(1 << 31))
 m_nQueryCounter = 0;
 else
 nCount = ++m_nQueryCounter;

 return m_pQueryConnections[nCount % m_nQueryConnPoolSize];
}

void Database::Ping()
{
 const char * sql = "SELECT 1";

 {
 SqlConnection::Lock guard(m_pAsyncConn);
 delete guard->Query(sql);
 }

 for (int i = 0; i < m_nQueryConnPoolSize; ++i)
 {
 SqlConnection::Lock guard(m_pQueryConnections[i]);
 delete guard->Query(sql);
 }
}

bool Database::PExecuteLog(const char * format,...)
{
 if (!format)
 return false;

 va_list ap;
 char szQuery [MAX_QUERY_LEN];
 va_start(ap, format);
 int res = vsnprintf( szQuery, MAX_QUERY_LEN, format, ap );
 va_end(ap);

 if(res==-1)
 {
 sLog.outError("SQL Query truncated (and not execute) for format: %s",format);
 return false;
 }

 if( m_logSQL )
 {
 time_t curr;
 tm local;
 time(&curr); // get current time_t value
 local=*(localtime(&curr)); // dereference and assign
 char fName[128];
 sprintf( fName, "%04d-%02d-%02d_logSQL.sql", local.tm_year+1900, local.tm_mon+1, local.tm_mday );

 FILE* log_file;
 std::string logsDir_fname = m_logsDir+fName;
 log_file = fopen(logsDir_fname.c_str(), "a");
 if (log_file)
 {
 fprintf(log_file, "%s;\n", szQuery);
 fclose(log_file);
 }
 else
 {
 // The file could not be opened
 sLog.outError("SQL-Logging is disabled - Log file for the SQL commands could not be openend: %s",fName);
 }
 }

 return Execute(szQuery);
}

QueryResult* Database::PQuery(const char *format,...)
{
 if(!format) return NULL;

 va_list ap;
 char szQuery [MAX_QUERY_LEN];
 va_start(ap, format);
 int res = vsnprintf( szQuery, MAX_QUERY_LEN, format, ap );
 va_end(ap);

 if(res==-1)
 {
 sLog.outError("SQL Query truncated (and not execute) for format: %s",format);
 return NULL;
 }

 return Query(szQuery);
}

QueryNamedResult* Database::PQueryNamed(const char *format,...)
{
 if(!format) return NULL;

 va_list ap;
 char szQuery [MAX_QUERY_LEN];
 va_start(ap, format);
 int res = vsnprintf( szQuery, MAX_QUERY_LEN, format, ap );
 va_end(ap);

 if(res==-1)
 {
 sLog.outError("SQL Query truncated (and not execute) for format: %s",format);
 return NULL;
 }

 return QueryNamed(szQuery);
}

bool Database::Execute(const char *sql)
{
 if (!m_pAsyncConn)
 return false;

 SqlTransaction * pTrans = m_TransStorage->get();
 if(pTrans)
 {
 //add SQL request to trans queue
 pTrans->DelayExecute(new SqlPlainRequest(sql));
 }
 else
 {
 //if async execution is not available
 if(!m_bAllowAsyncTransactions)
 return DirectExecute(sql);

 // Simple sql statement
 AddToDelayQueue(new SqlPlainRequest(sql));
 }

 return true;
}

bool Database::PExecute(const char * format,...)
{
 if (!format)
 return false;

 va_list ap;
 char szQuery [MAX_QUERY_LEN];
 va_start(ap, format);
 int res = vsnprintf( szQuery, MAX_QUERY_LEN, format, ap );
 va_end(ap);

 if(res==-1)
 {
 sLog.outError("SQL Query truncated (and not execute) for format: %s",format);
 return false;
 }

 return Execute(szQuery);
}

bool Database::DirectPExecute(const char * format,...)
{
 if (!format)
 return false;

 va_list ap;
 char szQuery [MAX_QUERY_LEN];
 va_start(ap, format);
 int res = vsnprintf( szQuery, MAX_QUERY_LEN, format, ap );
 va_end(ap);

 if(res==-1)
 {
 sLog.outError("SQL Query truncated (and not execute) for format: %s",format);
 return false;
 }

 return DirectExecute(szQuery);
}

bool Database::BeginTransaction(uint32 serialId)
{
 if (!m_pAsyncConn)
 return false;
 //ASSERT(!m_TransStorage->get());
 if (m_TransStorage->get())
 return false;

 //initiate transaction on current thread
 m_TransStorage->init(serialId);
 return true;
}

bool Database::InTransaction()
{
 return m_TransStorage->get() != NULL;
}

uint32 Database::GetTransactionSerialId()
{
 if (SqlTransaction *trans = m_TransStorage->get())
 return trans->GetSerialId();

 return 0;
}

bool Database::CommitTransaction()
{
 if (!m_pAsyncConn)
 return false;

 //check if we have pending transaction
 //ASSERT(m_TransStorage->get());
 if (!m_TransStorage->get())
 return false;

 //if async execution is not available
 if(!m_bAllowAsyncTransactions)
 return CommitTransactionDirect();

 //add SqlTransaction to the async queue
 // if serial ID > 0, add to the serial delay queue
 SqlTransaction *trans = m_TransStorage->detach();
 if (trans->GetSerialId() > 0)
 AddToSerialDelayQueue(trans);
 else
 AddToDelayQueue(trans);
 return true;
}

bool Database::CommitTransactionDirect()
{
 if (!m_pAsyncConn)
 return false;

 //check if we have pending transaction
 ASSERT (m_TransStorage->get());

 //directly execute SqlTransaction
 SqlTransaction * pTrans = m_TransStorage->detach();
 pTrans->Execute(m_pAsyncConn);
 delete pTrans;

 return true;
}

bool Database::RollbackTransaction()
{
 if (!m_pAsyncConn)
 return false;

 if(!m_TransStorage->get())
 return false;

 //remove scheduled transaction
 m_TransStorage->reset();

 return true;
}

void Database::AddToSerialDelayQueue(SqlOperation *op)
{
 if (op->GetSerialId() == 0 || m_numAsyncWorkers == 0)
 {
 AddToDelayQueue(op);
 return;
 }

 // This is a very naive way of doing this. No load balancing.
 // TODO: Load balance, must maintain mapping of serial ID so queries are
 // executed sequentially, however
 int worker = op->GetSerialId() % m_numAsyncWorkers;
 m_serialDelayQueue[worker]->add(op);
}

bool Database::NextSerialDelayedOperation(int workerId, SqlOperation*& op)
{
 if (workerId >= m_numAsyncWorkers)
 return false;

 return m_serialDelayQueue[workerId]->next(op);
}

bool Database::HasAsyncQuery()
{
 bool hasQuery = !m_delayQueue->empty_unsafe();

 for (int i = 0; i < m_numAsyncWorkers && m_serialDelayQueue && !hasQuery; ++i)
 hasQuery = !m_serialDelayQueue[i]->empty_unsafe();

 return hasQuery;
}

bool Database::CheckRequiredMigrations(const char **migrations)
{
 std::set<std::string> appliedMigrations;

 QueryResult *result = Query("SELECT * FROM `migrations`");

 if (result)
 {
 do
 {
 appliedMigrations.insert(result->Fetch()[0].GetString());
 } while (result->NextRow());
 delete result;
 }

 std::set<std::string> missingMigrations;

 while (migrations && *migrations)
 {
 std::set<std::string>::iterator it = appliedMigrations.find(*migrations);

 if (it == appliedMigrations.end())
 missingMigrations.insert(*migrations);
 else
 appliedMigrations.erase(it);

 migrations++;
 }

 result = Query("SELECT DATABASE()");

 if (!result)
 return false;

 std::string dbName = result->Fetch()[0].GetString();
 delete result;

 if (!missingMigrations.empty())
 {
 sLog.outErrorDb("Database `%s` is missing the following migrations:", dbName.c_str());

 for (std::set<std::string>::const_iterator it = missingMigrations.begin(); it != missingMigrations.end(); it++)
 sLog.outErrorDb("\t%s", (*it).c_str());

 return false;
 }

 if (!appliedMigrations.empty())
 {
 sLog.outErrorDb("WARNING! Database `%s` has the following extra migrations:", dbName.c_str());

 for (std::set<std::string>::const_iterator it = appliedMigrations.begin(); it != appliedMigrations.end(); it++)
 sLog.outErrorDb("\t%s", (*it).c_str());
 }

 return true;
}

bool Database::ExecuteStmt(const SqlStatementID& id, SqlStmtParameters * params)
{
 if (!m_pAsyncConn)
 return false;

 SqlTransaction * pTrans = m_TransStorage->get();
 if(pTrans)
 {
 //add SQL request to trans queue
 pTrans->DelayExecute(new SqlPreparedRequest(id.ID(), params));
 }
 else
 {
 //if async execution is not available
 if(!m_bAllowAsyncTransactions)
 return DirectExecuteStmt(id, params);

 // Simple sql statement
 AddToDelayQueue(new SqlPreparedRequest(id.ID(), params));
 }

 return true;
}

bool Database::DirectExecuteStmt( const SqlStatementID& id, SqlStmtParameters * params )
{
 MANGOS_ASSERT(params);
 std::unique_ptr<SqlStmtParameters> p(params);
 //execute statement
 SqlConnection::Lock _guard(getAsyncConnection());
 return _guard->ExecuteStmt(id.ID(), *params);
}

SqlStatement Database::CreateStatement(SqlStatementID& index, const char * fmt )
{
 int nId = -1;
 //check if statement ID is initialized
 if(!index.initialized())
 {
 //convert to lower register
 std::string szFmt(fmt);
 //count input parameters
 int nParams = std::count(szFmt.begin(), szFmt.end(), '?');
 //find existing or add a new record in registry
 LOCK_GUARD _guard(m_stmtGuard);
 PreparedStmtRegistry::const_iterator iter = m_stmtRegistry.find(szFmt);
 if(iter == m_stmtRegistry.end())
 {
 nId = ++m_iStmtIndex;
 m_stmtRegistry[szFmt] = nId;
 }
 else
 nId = iter->second;

 //save initialized statement index info
 index.init(nId, nParams);
 }

 return SqlStatement(index, *this);
}

std::string Database::GetStmtString(const int stmtId) const
{
 LOCK_GUARD _guard(m_stmtGuard);

 if(stmtId == -1 || stmtId > m_iStmtIndex)
 return std::string();

 PreparedStmtRegistry::const_iterator iter_last = m_stmtRegistry.end();
 for(PreparedStmtRegistry::const_iterator iter = m_stmtRegistry.begin(); iter != iter_last; ++iter)
 {
 if(iter->second == stmtId)
 return iter->first;
 }

 return std::string();
}

//HELPER CLASSES AND FUNCTIONS
Database::TransHelper::~TransHelper()
{
 reset();
}

SqlTransaction * Database::TransHelper::init(uint32 serialId)
{
 MANGOS_ASSERT(!m_pTrans); //if we will get a nested transaction request - we MUST fix code!!!
 m_pTrans = new SqlTransaction(serialId);

 return m_pTrans;
}

SqlTransaction * Database::TransHelper::detach()
{
 SqlTransaction * pRes = m_pTrans;
 m_pTrans = NULL;
 return pRes;
}

void Database::TransHelper::reset()
{
 if(m_pTrans)
 {
 delete m_pTrans;
 m_pTrans = NULL;
 }
}