#include "DataCondenser.h"
#include "Util/Util.h"
#include <iostream>
#include <limits>
#include <map>
#include <memory>
#include <sstream>


namespace DataStorageInterface {
namespace DataInterface {

DataCondenser::DataCondenser(MySQL::MySQLClient* pMySQLClient) :
	m_pMySQLClient(pMySQLClient)
{
}

void DataCondenser::CondenseData()
{
	auto deviceIDs = GetDeviceIDs();

	for (int dataId = 0; dataId < 3; ++dataId)
	{
		std::cout << "DataID: " << dataId << std::endl;

		//std::cout << "Daily" << std::endl;
		//for (auto& deviceId : deviceIDs)
		//	WriteReducedData(deviceId, dataId, RRA::Daily);
		std::cout << "Weekly" << std::endl;
		for (auto& deviceId : deviceIDs)
			WriteReducedData(deviceId, dataId, RRA::Weekly);
		std::cout << "Monthly" << std::endl;
		for (auto& deviceId : deviceIDs)
			WriteReducedData(deviceId, dataId, RRA::Monthly);
		std::cout << "Yearly" << std::endl;
		for (auto& deviceId : deviceIDs)
			WriteReducedData(deviceId, dataId, RRA::Yearly);
	}

	CleanData();
}

int DataCondenser::GetPeriodStamp(int timestamp, const RRA::type& rra)
{
	int modulo = timestamp % static_cast<int>(rra);
	return timestamp - modulo;
}

std::vector<int> DataCondenser::GetDeviceIDs()
{
	std::stringstream query;
	query << "SELECT DISTINCT `device_id` FROM `datalog` ORDER BY `device_id`;";
	auto resultSet = m_pMySQLClient->ExecuteQuery(query.str());

	std::vector<int> returnValue;
	while (resultSet.Next())
		returnValue.push_back(resultSet.Int("device_id"));

	return returnValue;
}

int DataCondenser::GetNewestPeriodStamp(const std::string& sourceTable, int deviceId, int dataId)
{
	std::stringstream query;
	query << "SELECT MAX(UNIX_TIMESTAMP(`timestamp`)) AS timestamp FROM `" << sourceTable << "` WHERE `device_id` = '" << deviceId <<"' AND `data_id` = '" << dataId << "';";
	auto resultSet = m_pMySQLClient->ExecuteQuery(query.str());
	if (resultSet.Next())
		return resultSet.Int("timestamp");

	return 0;
}

MySQL::MySQLResultSet DataCondenser::GetRawData(const std::string& sourceTable, int deviceId, int dataId, int newestPeriodStamp)
{
	std::stringstream query;
	query << "SELECT UNIX_TIMESTAMP(`timestamp`) AS timestamp, `value` AS `min-value`, `value` AS `mean-value`, `value` AS `max-value` FROM `" << sourceTable << "` WHERE `device_id` = '" << deviceId <<"' AND `data_id` = '" << dataId << "' ";
	if (newestPeriodStamp == -1)
		query << "LIMIT 1;";
	else
		query << "AND `timestamp` > FROM_UNIXTIME(" << newestPeriodStamp << ") ORDER BY `timestamp` ASC;";

	return m_pMySQLClient->ExecuteQuery(query.str());
}

MySQL::MySQLResultSet DataCondenser::GetReducedData(const std::string& sourceTable, int deviceId, int dataId, int newestPeriodStamp)
{
	std::stringstream query;
	query << "SELECT UNIX_TIMESTAMP(`timestamp`) AS timestamp, `min-value`, `mean-value`, `max-value` FROM `" << sourceTable << "` WHERE `device_id` = '" << deviceId <<"' AND `data_id` = '" << dataId << "' ";
	if (newestPeriodStamp == -1)
		query << "LIMIT 1;";
	else
		query << "AND `timestamp` > FROM_UNIXTIME(" << newestPeriodStamp << ") ORDER BY `timestamp` ASC;";

	return m_pMySQLClient->ExecuteQuery(query.str());
}

int DataCondenser::GetMaximumMySQLPacketSize()
{
	std::stringstream query;
	query << "show variables like 'max_allowed_packet';";
	MySQL::MySQLResultSet resultSet = m_pMySQLClient->ExecuteQuery(query.str());

	if (resultSet.RowsCount() != 1)
		throw std::runtime_error("Unexpected reply when retrieving max_allowed_packet.");

	resultSet.Next();
	return resultSet.Int("Value");
}

DataType::type DataCondenser::GetDataType(int deviceId, int dataId)
{
	auto resultSet = GetRawData("datalog", deviceId, dataId, -1);
	if (resultSet.Next())
		return DataInterface::GetDataType(resultSet.String("mean-value"));

	return DataType::None;
}

std::string DataCondenser::GetSourceTable(const RRA::type& rra)
{
	switch (rra)
	{
	case RRA::Daily:
		return "datalog";
	case RRA::Weekly:
		return "datalog";
	case RRA::Monthly:
		return "datalog-weekly";
	case RRA::Yearly:
		return "datalog-monthly";
	default:
	case RRA::Raw:
		return std::string();
	}
}

std::string DataCondenser::GetDestinationTable(const RRA::type& rra)
{
	switch (rra)
	{
	case RRA::Daily:
		return "datalog-daily";
	case RRA::Weekly:
		return "datalog-weekly";
	case RRA::Monthly:
		return "datalog-monthly";
	case RRA::Yearly:
		return "datalog-yearly";
	default:
	case RRA::Raw:
		return std::string();
	}
}

int DataCondenser::StringStreamSize(std::stringstream& ss)
{
	ss.seekp(0, std::ios_base::end);
	return ss.tellp();
}

void DataCondenser::InitializeInsertQuery(std::stringstream& query, const std::string& table)
{
	query.str("");
	query << "INSERT INTO `" << table << "` (`device_id`, `data_id`, `timestamp`, `min-value`, `mean-value`, `max-value`) VALUES ";
}

void DataCondenser::ExecuteInsertQuery(std::stringstream& query)
{
	query.seekp(-1, std::ios_base::end);
	query << ";";
	m_pMySQLClient->Execute(query.str());
}

void DataCondenser::WriteReducedData(int deviceId, int dataId, const RRA::type& rra)
{
	DataType::type dataType = GetDataType(deviceId, dataId);

	if (dataType == DataType::None)
		std::cout << " DataType: None" << std::endl;
	else if (dataType == DataType::Float)
		std::cout << " DataType: Float" << std::endl;
	else if (dataType == DataType::String)
		std::cout << " DataType: String" << std::endl;

	switch (dataType)
	{
	case DataType::Float:
		WriteReducedFloatData(deviceId, dataId, rra);
		break;
	case DataType::String:
		WriteReducedStringData(deviceId, dataId, rra);
		break;
	default:
	case DataType::None:
		break;
	}
}

void DataCondenser::WriteReducedFloatData(int deviceId, int dataId, const RRA::type& rra)
{
	int maxMySQLPacketSize = GetMaximumMySQLPacketSize() - 2;

	std::string sourceTable = GetSourceTable(rra);
	std::string destinationTable = GetDestinationTable(rra);

	int newestSourcePeriodStamp = GetNewestPeriodStamp(sourceTable, deviceId, dataId);
	int newestDestinationPeriodStamp = GetNewestPeriodStamp(destinationTable, deviceId, dataId);

	std::cout << " DeviceID: " << deviceId << std::endl;
	std::cout << " DataID: " << dataId << std::endl;
	std::cout << "  Newest Src : " << newestSourcePeriodStamp << std::endl;
	std::cout << "  Newest Dest: " << newestDestinationPeriodStamp << std::endl;

	std::stringstream query;
	MySQL::MySQLResultSet resultSet;
	if (sourceTable == "datalog")
		resultSet = GetRawData(sourceTable, deviceId, dataId, newestDestinationPeriodStamp);
	else
		resultSet = GetReducedData(sourceTable, deviceId, dataId, newestDestinationPeriodStamp);

	std::cout << " Source Count: " << resultSet.RowsCount() << std::endl;

	int samples = 0;
	float min = std::numeric_limits<float>::max();
	float mean = 0;
	float max = std::numeric_limits<float>::min();

	int writeCount = 0;

	InitializeInsertQuery(query, destinationTable);

	std::stringstream queryPart;

	int periodStamp = 0;
	while (resultSet.Next())
	{
		int currentPeriodStamp = GetPeriodStamp(resultSet.Int("timestamp"), rra);
		if (currentPeriodStamp != periodStamp)
		{
			if (samples > 0)
			{
				mean = mean / samples;

				queryPart.str("");
				queryPart << "('" << deviceId << "', '" << dataId << "', FROM_UNIXTIME(" << currentPeriodStamp << "), '" << min << "', '" << mean << "', '" << max << "'),";
				++writeCount;

				int packetSize = StringStreamSize(query) + StringStreamSize(queryPart);
				if (packetSize > maxMySQLPacketSize)
				{
					ExecuteInsertQuery(query);
					InitializeInsertQuery(query, destinationTable);
					std::cout << " Write Count: " << writeCount << std::endl;
					writeCount = 0;
				}

				query << queryPart.str();
			}

			if (currentPeriodStamp > newestSourcePeriodStamp)
				break;

			samples = 0;
			min = std::numeric_limits<float>::max();
			mean = 0;
			max = std::numeric_limits<float>::min();
			periodStamp = currentPeriodStamp;
		}

		float minValue, meanValue, maxValue;
		minValue = static_cast<float>(resultSet.Double("min-value"));
		meanValue = static_cast<float>(resultSet.Double("mean-value"));
		maxValue = static_cast<float>(resultSet.Double("max-value"));

		if (minValue < min)
			min = minValue;
		if (maxValue > max)
			max = maxValue;
		mean += meanValue;
		++samples;
	}

	if (writeCount > 0)
		ExecuteInsertQuery(query);

	std::cout << " Write Count: " << writeCount << std::endl << std::endl;
}

void DataCondenser::WriteReducedStringData(int deviceId, int dataId, const RRA::type& rra)
{
	int maxMySQLPacketSize = GetMaximumMySQLPacketSize() - 2;

	std::string sourceTable = GetSourceTable(rra);
	std::string destinationTable = GetDestinationTable(rra);

	int newestSourcePeriodStamp = GetNewestPeriodStamp(sourceTable, deviceId, dataId);
	int newestDestinationPeriodStamp = GetNewestPeriodStamp(destinationTable, deviceId, dataId);

	std::cout << " DeviceID: " << deviceId << std::endl;
	std::cout << " DataID: " << dataId << std::endl;
	std::cout << "  Newest Src : " << newestSourcePeriodStamp << std::endl;
	std::cout << "  Newest Dest: " << newestDestinationPeriodStamp << std::endl;

	std::stringstream query;
	MySQL::MySQLResultSet resultSet;
	if (sourceTable == "datalog")
		resultSet = GetRawData(sourceTable, deviceId, dataId, newestDestinationPeriodStamp);
	else
		resultSet = GetReducedData(sourceTable, deviceId, dataId, newestDestinationPeriodStamp);

	std::cout << " Source Count: " << resultSet.RowsCount() << std::endl;

	int samples = 0;
	std::vector<std::string> values;

	int writeCount = 0;

	InitializeInsertQuery(query, destinationTable);

	std::stringstream queryPart;

	int periodStamp = 0;
	while (resultSet.Next())
	{
		int currentPeriodStamp = GetPeriodStamp(resultSet.Int("timestamp"), rra);
		if (currentPeriodStamp != periodStamp)
		{
			if (samples > 0)
			{
				std::map<std::string, int> map;
				for (auto& value : values)
				{
					auto iterator = map.find(value);
					if (iterator == map.end())
						map.insert(std::pair<std::string, int>(value, 1));
					else
						map[value] += 1;
				}

				auto iterator = map.begin();
				for (std::map<std::string, int>::iterator it = map.begin(); it != map.end(); ++it)
				{
					if (it->second > iterator->second)
						iterator = it;
				}

				queryPart.str("");
				queryPart << "('" << deviceId << "', '" << dataId << "', FROM_UNIXTIME(" << currentPeriodStamp << "), '', '" << iterator->first << "', ''),";

				int packetSize = StringStreamSize(query) + StringStreamSize(queryPart);
				if (packetSize > maxMySQLPacketSize)
				{
					ExecuteInsertQuery(query);
					InitializeInsertQuery(query, destinationTable);
					std::cout << " Write Count: " << writeCount << std::endl;
					writeCount = 0;
				}

				query << queryPart.str();
				++writeCount;
			}

			if (currentPeriodStamp > newestSourcePeriodStamp)
				break;

			samples = 0;
			values.clear();
			periodStamp = currentPeriodStamp;
		}

		std::string meanValue = resultSet.String("mean-value");
		values.push_back(meanValue);
		++samples;
	}

	if (writeCount > 0)
		ExecuteInsertQuery(query);

	std::cout << " Write Count: " << writeCount << std::endl << std::endl;
}

void DataCondenser::CleanData()
{
	std::cout << "Cleaning: " << std::endl;

	CleanData(RRA::Daily);
	CleanData(RRA::Weekly);
	CleanData(RRA::Monthly);
	CleanData(RRA::Yearly);
}

void DataCondenser::CleanData(const RRA::type& rra)
{
	std::string table = GetDestinationTable(rra);
	int periodInSeconds = static_cast<int>(rra) * 400;
	int timestamp = Util::GetTimestamp() + Util::GetUTCOffset() - periodInSeconds;

	std::cout << " Cleaning " << table << " (<" << timestamp << ")" << std::endl;

	std::stringstream query;
	query << "DELETE FROM `" << table << "` WHERE `timestamp` < FROM_UNIXTIME(" << timestamp << ");";
	m_pMySQLClient->Execute(query.str());
}

} // namespace DataInterface
} // namespace DataStorageInterface