/*
 * DriverPostgres.cpp -- PostgreSQL driver
 *
 * Copyright (c) 2013, David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sstream>

#include "DriverPostgres.h"

/* --------------------------------------------------------
 * Query PostgreSQL (protected methods)
 * -------------------------------------------------------- */

QueryCheck QueryPostgres::checkRequest(int row, const std::string &column, ColumnType type)
{
	QueryCheck ret = QueryCheck::InvalidType;
	Oid pqType;
	int colIndex;
	bool success = false;

	// Invalid row
	if (row >= PQntuples(m_result.get()))
		return QueryCheck::InvalidRow;
	if ((colIndex = PQfnumber(m_result.get(), column.c_str())) == -1)
		return QueryCheck::InvalidColumn;

	pqType = PQftype(m_result.get(), colIndex);
	switch (type)
	{
	case ColumnType::Boolean:
		success = (pqType == 16);
		break;
	case ColumnType::Date:
		success = (pqType == 1082) || (pqType == 1083) || (pqType == 1114);
		break;
	case ColumnType::Double:
		success = (pqType = 1700) || (pqType == 700) || (pqType == 701);
		break;
	case ColumnType::Integer:
		success = (pqType == 20) || (pqType == 21) || (pqType == 23) || (pqType == 1700);
		break;
	case ColumnType::String:
		success = (pqType == 25) || (pqType == 1042) || (pqType == 1043);
		break;
	default:
		ret = QueryCheck::InvalidType;
	}

	// valid type requested?
	if (success)
		ret = QueryCheck::NoError;

	return ret;
}

/* --------------------------------------------------------
 * Query PostgreSQL (public methods)
 * -------------------------------------------------------- */

QueryPostgres::QueryPostgres(PostgresResult result)
{
	m_result = std::move(result);
}

QueryPostgres::~QueryPostgres()
{
}

int QueryPostgres::countRows()
{
	return PQntuples(m_result.get());
}

int QueryPostgres::countColumns()
{
	return PQnfields(m_result.get());
}

bool QueryPostgres::checkBool(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());
	std::string code = PQgetvalue(m_result.get(), row, idx);

	return code[0] == 't';
}

Date QueryPostgres::checkDate(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());
	long timestamp = static_cast<long>(time(0));

	try
	{
		timestamp = std::stol(PQgetvalue(m_result.get(), row, idx));
	}
	catch (std::invalid_argument)
	{
	}

	return Date(static_cast<time_t>(timestamp));
}

double QueryPostgres::checkDouble(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());
	double d = 0;

	try
	{
		d = std::stod(PQgetvalue(m_result.get(), row, idx));
	}
	catch (std::invalid_argument)
	{
	}

	return d;
}

int QueryPostgres::checkInt(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());
	int i = 0;

	try
	{
		i = std::stoi(PQgetvalue(m_result.get(), row, idx));
	}
	catch (std::invalid_argument)
	{
	}

	return i;
}

std::string QueryPostgres::checkString(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());

	return std::string(PQgetvalue(m_result.get(), row, idx));
}

bool QueryPostgres::isNull(int row, const std::string &column)
{
	int idx = PQfnumber(m_result.get(), column.c_str());

	return PQgetisnull(m_result.get(), row, idx) == 1;
}

void QueryPostgres::dump(void)
{
	std::cout << "Dumping PostgreSQL result, ";
	std::cout << countRows() << " rows, ";
	std::cout << countColumns() << " columns" << std::endl;

	for (int r = 0; r < countRows(); ++r)
	{
		std::cout << "Dumping row " << r << std::endl;
		std::cout << "==============================" << std::endl;

		for (int c = 0; c < countColumns(); ++c)
		{
			std::cout << "\t" << PQfname(m_result.get(), c);
			std::cout << " = " << PQgetvalue(m_result.get(), r, c) << std::endl;
		}
	}
}

/* --------------------------------------------------------
 * Driver PostgreSQL
 * -------------------------------------------------------- */

DriverPostgres::DriverPostgres()
{
}

DriverPostgres::~DriverPostgres()
{
}

std::string DriverPostgres::convert(Params &params)
{
	std::ostringstream oss;

	oss << "host = " << params["host"] << " ";
	oss << "port = " << params["port"] << " ";
	oss << "user = " << params["user"] << " ";
	oss << "dbname = " << params["database"] << " ";
	oss << "password = " << params["password"];

	return oss.str();
}

bool DriverPostgres::connect(const Params &params)
{
	Params copy = params;
	PGconn *conn = PQconnectdb(convert(copy).c_str());

	if (conn == nullptr)
	{
		m_error = strerror(ENOMEM);
		return false;
	}

	if (PQstatus(conn) == CONNECTION_BAD)
	{
		m_error = PQerrorMessage(conn);
		PQfinish(conn);

		return false;
	}

	m_connection = PostgresConn(conn);

	return true;
}

std::unique_ptr<Query> DriverPostgres::query(const std::string &cmd)
{
	PGresult *info;

	// If NULL, the libpq said no memory
	info = PQexec(m_connection.get(), cmd.c_str());
	if (info == nullptr)
		throw QueryError(strerror(ENOMEM));

	// If an error occured
	int errorCode = PQresultStatus(info);
	if (errorCode != PGRES_COMMAND_OK && errorCode != PGRES_TUPLES_OK)
	{
		std::string error = PQresultErrorMessage(info);
		PQclear(info);
		throw QueryError(error);
	}

	return std::unique_ptr<Query>(new QueryPostgres(QueryPostgres::PostgresResult(info)));
}

std::string DriverPostgres::description() const
{
	std::ostringstream oss;

	oss << "Connected on PostgreSQL database: " << std::endl;
	oss << "  host: " << PQhost(m_connection.get()) << std::endl;
	oss << "  port: " << PQport(m_connection.get()) << std::endl;
	oss << "  user: " << PQuser(m_connection.get()) << std::endl;
	oss << "  database: " << PQdb(m_connection.get()) << std::endl;

	return oss.str();
}