// vim: set ts=4 sw=4 tw=99 noet:
//
// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
// Copyright (C) The AMX Mod X Development Team.
//
// This software is licensed under the GNU General Public License, version 3 or higher.
// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
//     https://alliedmods.net/amxmodx-license

//
// MySQL Module
//

#include "amxxmodule.h"
#include "mysql2_header.h"
#include "threading.h"

using namespace SourceMod;

MainThreader g_Threader;
ThreadWorker *g_pWorker = NULL;
extern DLL_FUNCTIONS *g_pFunctionTable;
IMutex *g_QueueLock = NULL;
CStack<MysqlThread *> g_ThreadQueue;
CStack<MysqlThread *> g_FreeThreads;
float g_lasttime = 0.0f;

void ShutdownThreading()
{
	if (g_pWorker)
	{
		// Flush all the remaining job fast!
		g_pWorker->SetMaxThreadsPerFrame(8192);
		g_pWorker->Stop(true);
		delete g_pWorker;
		g_pWorker = NULL;
	}

	g_QueueLock->Lock();
	while (!g_ThreadQueue.empty())
	{
		delete g_ThreadQueue.front();
		g_ThreadQueue.pop();
	}
	while (!g_FreeThreads.empty())
	{
		delete g_FreeThreads.front();
		g_FreeThreads.pop();
	}
	g_QueueLock->Unlock();
	g_QueueLock->DestroyThis();

	FreeHandleTable();
}

//public QueryHandler(state, Handle:query, error[], errnum, data[], size)
//native SQL_ThreadQuery(Handle:cn_tuple, const handler[], const query[], const data[]="", dataSize=0);
static cell AMX_NATIVE_CALL SQL_ThreadQuery(AMX *amx, cell *params)
{
	if (!g_pWorker)
	{
		MF_LogError(amx, AMX_ERR_NATIVE, "Thread worker was unable to start.");
		return 0;
	}

	SQL_Connection *cn = (SQL_Connection *)GetHandle(params[1], Handle_Connection);
	if (!cn)
	{
		MF_LogError(amx, AMX_ERR_NATIVE, "Invalid info tuple handle: %d", params[1]);
		return 0;
	}

	int len;
	const char *handler = MF_GetAmxString(amx, params[2], 0, &len);
	int fwd = MF_RegisterSPForwardByName(amx, handler, FP_CELL, FP_CELL, FP_STRING, FP_CELL, FP_ARRAY, FP_CELL, FP_CELL, FP_DONE);
	if (fwd < 1)
	{
		MF_LogError(amx, AMX_ERR_NATIVE, "Function not found: %s", handler);
		return 0;
	}

	MysqlThread *kmThread;
	g_QueueLock->Lock();
	if (g_FreeThreads.empty())
	{
		kmThread = new MysqlThread();
	} 
	else 
	{
		kmThread = g_FreeThreads.front();
		g_FreeThreads.pop();
	}
	g_QueueLock->Unlock();

	kmThread->SetInfo(cn->host, cn->user, cn->pass, cn->db, cn->port, cn->max_timeout);
	kmThread->SetForward(fwd);
	kmThread->SetQuery(MF_GetAmxString(amx, params[3], 1, &len));
	kmThread->SetCellData(MF_GetAmxAddr(amx, params[4]), (ucell)params[5]);
	kmThread->SetCharacterSet(cn->charset);

	g_pWorker->MakeThread(kmThread);

	return 1;
}

MysqlThread::MysqlThread()
{
	m_fwd = 0;
	m_data = NULL;
	m_datalen = 0;
	m_maxdatalen = 0;
}

MysqlThread::~MysqlThread()
{
	if (m_fwd)
	{
		MF_UnregisterSPForward(m_fwd);
		m_fwd = 0;
	}
	
	delete [] m_data;
	m_data = NULL;
}

void MysqlThread::SetCellData(cell data[], ucell len)
{
	if (len > m_maxdatalen)
	{
		delete [] m_data;
		m_data = new cell[len];
		m_maxdatalen = len;
	}
	if (len)
	{
		m_datalen = len;
		memcpy(m_data, data, len*sizeof(cell));
	}
}

void MysqlThread::SetForward(int forward)
{
	m_fwd = forward;
}

void MysqlThread::SetInfo(const char *host, const char *user, const char *pass, const char *db, int port, unsigned int max_timeout)
{
	m_host = host;
	m_user = user;
	m_pass = pass;
	m_db = db;
	m_max_timeout = max_timeout;
	m_port = port;
	m_qrInfo.queue_time = gpGlobals->time;
}

void MysqlThread::SetCharacterSet(const char *charset)
{
	m_charset = charset;
}

void MysqlThread::SetQuery(const char *query)
{
	m_query = query;
}

void MysqlThread::RunThread(IThreadHandle *pHandle)
{
	DatabaseInfo info;

	info.database = m_db.chars();
	info.pass = m_pass.chars();
	info.user = m_user.chars();
	info.host = m_host.chars();
	info.port = m_port;
	info.max_timeout = m_max_timeout;
	info.charset = m_charset.chars();

	float save_time = m_qrInfo.queue_time;

	memset(static_cast<void *>(&m_qrInfo), 0, sizeof(m_qrInfo));

	m_qrInfo.queue_time = save_time;

	IDatabase *pDatabase = g_Mysql.Connect2(&info, &m_qrInfo.amxinfo.info.errorcode, m_qrInfo.amxinfo.error, 254);
	IQuery *pQuery = NULL;
	if (!pDatabase)
	{
		m_qrInfo.connect_success = false;
		m_qrInfo.query_success = false;
	} 
	else 
	{
		m_qrInfo.connect_success = true;
		pQuery = pDatabase->PrepareQuery(m_query.chars());
		if (!pQuery->Execute2(&m_qrInfo.amxinfo.info, m_qrInfo.amxinfo.error, 254))
		{
			m_qrInfo.query_success = false;
		} 
		else 
		{
			m_qrInfo.query_success = true;
		}
	}

	if (m_qrInfo.query_success && m_qrInfo.amxinfo.info.rs)
	{
		m_atomicResult.CopyFrom(m_qrInfo.amxinfo.info.rs);
		m_qrInfo.amxinfo.info.rs = &m_atomicResult;
	}

	if (pQuery)
	{
		pQuery->FreeHandle();
		pQuery = NULL;
	} 

	m_qrInfo.amxinfo.pQuery = NULL;
	m_qrInfo.amxinfo.opt_ptr = new char[m_query.length() + 1];
	strcpy(m_qrInfo.amxinfo.opt_ptr, m_query.chars());

	if (pDatabase)
	{
		pDatabase->FreeHandle();
		pDatabase = NULL;
	}
}

void MysqlThread::Invalidate()
{
	m_atomicResult.FreeHandle();
}

void MysqlThread::OnTerminate(IThreadHandle *pHandle, bool cancel)
{
	if (cancel)
	{
		Invalidate();
		g_QueueLock->Lock();
		g_FreeThreads.push(this);
		g_QueueLock->Unlock();
	} else {
		g_QueueLock->Lock();
		g_ThreadQueue.push(this);
		g_QueueLock->Unlock();
	}
}

void NullFunc(void *ptr, unsigned int num)
{
}

//public QueryHandler(state, Handle:query, error[], errnum, data[], size)
void MysqlThread::Execute()
{
	cell data_addr;
	if (m_datalen)
	{
		data_addr = MF_PrepareCellArray(m_data, m_datalen);
	} 
	else 
	{
		static cell tmpdata[1] = {0};
		data_addr = MF_PrepareCellArray(tmpdata, 1);
	}
	int state = 0;
	if (!m_qrInfo.connect_success)
	{
		state = -2;
	} 
	else if (!m_qrInfo.query_success) 
	{
		state = -1;
	}
	float diff = gpGlobals->time - m_qrInfo.queue_time;
	cell c_diff = amx_ftoc(diff);
	unsigned int hndl = MakeHandle(&m_qrInfo.amxinfo, Handle_Query, NullFunc);
	if (state != 0)
	{
		MF_ExecuteForward(m_fwd, 
			(cell)state, 
			(cell)hndl, 
			m_qrInfo.amxinfo.error, 
			m_qrInfo.amxinfo.info.errorcode,
			data_addr,
			m_datalen,
			c_diff);
	} 
	else 
	{
		MF_ExecuteForward(m_fwd,
			(cell)0,
			(cell)hndl,
			"",
			(cell)0,
			data_addr,
			m_datalen,
			c_diff);
	}
	FreeHandle(hndl);
	delete [] m_qrInfo.amxinfo.opt_ptr;
	m_qrInfo.amxinfo.opt_ptr = NULL;
}

/*****************
 * METAMOD STUFF *
 *****************/

void OnPluginsLoaded()
{
	if (g_pWorker)
	{
		return;
	}

	if (!g_QueueLock)
	{
		g_QueueLock = g_Threader.MakeMutex();
	}

	g_pWorker = new ThreadWorker(&g_Threader, DEFAULT_THINK_TIME_MS);
	if (!g_pWorker->Start())
	{
		delete g_pWorker;
		g_pWorker = NULL;
	}
	g_pFunctionTable->pfnSpawn = NULL;

	g_lasttime = 0.0f;

	return;
}

void StartFrame()
{
	if (g_pWorker && (g_lasttime < gpGlobals->time))
	{
		g_lasttime = gpGlobals->time + 0.025f;
		g_QueueLock->Lock();
		size_t remaining = g_ThreadQueue.size();
		if (remaining)
		{
			MysqlThread *kmThread;
			do 
			{
				kmThread = g_ThreadQueue.front();
				g_ThreadQueue.pop();
				g_QueueLock->Unlock();
				kmThread->Execute();
				kmThread->Invalidate();
				g_FreeThreads.push(kmThread);
				g_QueueLock->Lock();
			} while (!g_ThreadQueue.empty());
		}

		g_QueueLock->Unlock();
	}

	RETURN_META(MRES_IGNORED);
}

void OnPluginsUnloading()
{
	if (!g_pWorker)
	{
		return;
	}

	// Flush all the remaining job fast!
	g_pWorker->SetMaxThreadsPerFrame(8192);
	g_pWorker->Stop(false);
	delete g_pWorker;
	g_pWorker = NULL;

	g_QueueLock->Lock();
	size_t remaining = g_ThreadQueue.size();
	if (remaining)
	{
		MysqlThread *kmThread;
		do 
		{
			kmThread = g_ThreadQueue.front();
			g_ThreadQueue.pop();
			g_QueueLock->Unlock();
			kmThread->Execute();
			kmThread->Invalidate();
			g_FreeThreads.push(kmThread);
			g_QueueLock->Lock();
		} while (!g_ThreadQueue.empty());
	}

	g_QueueLock->Unlock();
}

/***********************
 * ATOMIC RESULT STUFF *
 ***********************/

AtomicResult::AtomicResult()
{
	m_IsFree = true;
	m_CurRow = 1;
	m_RowCount = 0;
	m_Table = NULL;
	m_AllocSize = 0;
}

AtomicResult::~AtomicResult()
{
	if (!m_IsFree)
	{
		FreeHandle();
	}

	for (size_t i=0; i<=m_AllocSize; i++)
	{
		delete m_Table[i];
	}

	delete [] m_Table;

	m_Table = NULL;
	m_IsFree = true;
}

unsigned int AtomicResult::RowCount()
{
	return m_RowCount;
}

bool AtomicResult::IsNull(unsigned int columnId)
{
	return (GetString(columnId) == NULL);
}

unsigned int AtomicResult::FieldCount()
{
	return m_FieldCount;
}

bool AtomicResult::FieldNameToNum(const char *name, unsigned int *columnId)
{
	for (unsigned int i=0; i<m_FieldCount; i++)
	{
		assert(m_Table[i] != NULL);
		if (strcmp(m_Table[i]->chars(), name) == 0)
		{
			if (columnId)
			{
				*columnId = i;
			}
			return true;
		}
	}

	return false;
}

const char *AtomicResult::FieldNumToName(unsigned int num)
{
	if (num >= m_FieldCount)
		return NULL;

	assert(m_Table[num] != NULL);

	return m_Table[num]->chars();
}

double AtomicResult::GetDouble(unsigned int columnId)
{
	return atof(GetStringSafe(columnId));
}

float AtomicResult::GetFloat(unsigned int columnId)
{
	return atof(GetStringSafe(columnId));
}

int AtomicResult::GetInt(unsigned int columnId)
{
	return atoi(GetStringSafe(columnId));
}

const char *AtomicResult::GetRaw(unsigned int columnId, size_t *length)
{
	//we don't support this yet...
	*length = 0;
	return "";
}

const char *AtomicResult::GetStringSafe(unsigned int columnId)
{
	const char *str = GetString(columnId);
	
	return str ? str : "";
}

const char *AtomicResult::GetString(unsigned int columnId)
{
	if (columnId >= m_FieldCount)
		return NULL;

	size_t idx = (m_CurRow * m_FieldCount) + columnId;

	assert(m_Table[idx] != NULL);

	return m_Table[idx]->chars();
}

IResultRow *AtomicResult::GetRow()
{
	return static_cast<IResultRow *>(this);
}

bool AtomicResult::IsDone()
{
	if (m_CurRow > m_RowCount)
		return true;

	return false;
}

void AtomicResult::NextRow()
{
	m_CurRow++;
}

void AtomicResult::_InternalClear()
{
	if (m_IsFree)
		return;

	m_IsFree = true;
}

void AtomicResult::FreeHandle()
{
	_InternalClear();
}

void AtomicResult::CopyFrom(IResultSet *rs)
{
	if (!m_IsFree)
	{
		_InternalClear();
	}

	m_IsFree = false;

	m_FieldCount = rs->FieldCount();
	m_RowCount = rs->RowCount();
	m_CurRow = 1;

	size_t newTotal = (m_RowCount * m_FieldCount) + m_FieldCount;
	if (newTotal > m_AllocSize)
	{
		ke::AString **table = new ke::AString *[newTotal];
		memset(table, 0, newTotal * sizeof(ke::AString *));
		if (m_Table)
		{
			memcpy(table, m_Table, m_AllocSize * sizeof(ke::AString *));
			delete [] m_Table;
		}
		m_Table = table;
		m_AllocSize = newTotal;
	}

	for (unsigned int i=0; i<m_FieldCount; i++)
	{
		if (m_Table[i])
		{
			*m_Table[i] = rs->FieldNumToName(i);
		} else {
			const char* string = rs->FieldNumToName(i);
			m_Table[i] = new ke::AString(string ? string : "");
		}
	}

	IResultRow *row;
	unsigned int idx = m_FieldCount;
	while (!rs->IsDone())
	{
		row = rs->GetRow();
		for (unsigned int i=0; i<m_FieldCount; i++,idx++)
		{
			if (m_Table[idx])
			{
				*m_Table[idx] = row->GetString(i);
			} else {
				const char* string = row->GetString(i);
				m_Table[idx] = new ke::AString(string ? string : "");
			}
		}
		rs->NextRow();
	}
}

void AtomicResult::Rewind()
{
	m_CurRow = 1;
}

bool AtomicResult::NextResultSet()
{
	return false;
}

AMX_NATIVE_INFO g_ThreadSqlNatives[] =
{
	{"SQL_ThreadQuery",			SQL_ThreadQuery},
	{NULL,						NULL},
};