/*
   Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.

   The MySQL Connector/C++ is licensed under the terms of the GPL
   <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
   MySQL Connectors. There are special exceptions to the terms and
   conditions of the GPL as it is applied to this software, see the
   FLOSS License Exception
   <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
*/

/* *
* Basic example demonstrating scrolling through a result set
*
*/

/* Standard C++ includes */
#include <stdlib.h>
#include <iostream>
#include <sstream>
#include <stdexcept>

/* Public interface of the MySQL Connector/C++ */
#include <driver/mysql_public_iface.h>
/* Connection parameter and sample data */
#include "examples.h"

static void validateResultSet(std::auto_ptr< sql::ResultSet > & res, struct _test_data *min, struct _test_data *max);

using namespace std;

int main(int argc, const char **argv)
{
	static const string url(argc >= 2 ? argv[1] : EXAMPLE_HOST);
	static const string user(argc >= 3 ? argv[2] : EXAMPLE_USER);
	static const string pass(argc >= 4 ? argv[3] : EXAMPLE_PASS);
	static const string database(argc >= 5 ? argv[4] : EXAMPLE_DB);

	/* Driver Manager */
	sql::Driver *driver;

	/* sql::ResultSet.rowsCount() returns size_t */
	stringstream sql;
	int i;
	struct _test_data min, max;

	cout << boolalpha;
	cout << "1..1" << endl;
	cout << "# Connector/C++ result set.." << endl;

	try {
		/* Using the Driver to create a connection */
		driver = sql::mysql::get_driver_instance();
		std::auto_ptr< sql::Connection > con(driver->connect(url, user, pass));

		con->setSchema(database);

		/* Creating a "simple" statement - "simple" = not a prepared statement */
		std::auto_ptr< sql::Statement > stmt(con->createStatement());
		stmt->execute("DROP TABLE IF EXISTS test");
		stmt->execute("CREATE TABLE test(id INT, label CHAR(1))");
		cout << "#\t Test table created" << endl;

		/* Populate the test table with data */
		min = max = test_data[0];
		for (i = 0; i < EXAMPLE_NUM_TEST_ROWS; i++) {
			/* Remember mnin/max values for further testing */
			if (test_data[i].id < min.id) {
				min = test_data[i];
			}
			if (test_data[i].id > max.id) {
				max = test_data[i];
			}

			/*
			KLUDGE: You should take measures against SQL injections!
			*/
			sql.str("");
			sql << "INSERT INTO test(id, label) VALUES (";
			sql << test_data[i].id << ", '" << test_data[i].label << "')";
			stmt->execute(sql.str());
		}
		cout << "#\t Test table populated" << endl;

		/*
		This is an example how to fetch in reverse order using the ResultSet cursor.
		Every ResultSet object maintains a cursor, which points to its current
		row of data. The cursor is 1-based. The first row has the cursor position 1.

		NOTE: The Connector/C++ preview/alpha uses buffered results.
		THe driver will always fetch all data no matter how big the result set is!
		*/
		cout << "#\t Testing sql::Statement based resultset" << endl;
		{
			std::auto_ptr< sql::ResultSet > res(stmt->executeQuery("SELECT id, label FROM test ORDER BY id ASC"));
			validateResultSet(res, &min, &max);
		}

		cout << "#" << endl;
		cout << "#\t Testing sql::PreparedStatment based resultset" << endl;

		{
			std::auto_ptr< sql::PreparedStatement > prep_stmt(con->prepareStatement("SELECT id, label FROM test ORDER BY id ASC"));
			std::auto_ptr< sql::ResultSet > res(prep_stmt->executeQuery());
			validateResultSet(res, &min, &max);
		}

		/* Clean up */
		stmt->execute("DROP TABLE IF EXISTS test");
		cout << "# done!" << endl;

	} catch (sql::SQLException &e) {
		/*
		The MySQL Connector/C++ throws three different exceptions:

		- sql::MethodNotImplementedException (derived from sql::SQLException)
		- sql::InvalidArgumentException (derived from sql::SQLException)
		- sql::SQLException (derived from std::runtime_error)
		*/
		cout << "# ERR: SQLException in " << __FILE__;
		cout << "(" << __FUNCTION__ << ") on line " << __LINE__ << endl;
		// Use what(), getErrorCode() and getSQLState()
		cout << "# ERR: " << e.what();
		cout << " (MySQL error code: " << e.getErrorCode();
		cout << ", SQLState: " << e.getSQLState() << " )" << endl;
		cout << "not ok 1 - examples/resultset.cpp" << endl;

		return EXIT_FAILURE;
	} catch (std::runtime_error &e) {

		cout << "# ERR: runtime_error in " << __FILE__;
		cout << "(" << __FUNCTION__ << ") on line " << __LINE__ << endl;
		cout << "# ERR: " << e.what() << endl;
		cout << "not ok 1 - examples/resultset.cpp" << endl;

		return EXIT_FAILURE;
	}

	cout << "ok 1 - examples/resultset.cpp" << endl;
	return EXIT_SUCCESS;
}

static void validateRow(std::auto_ptr< sql::ResultSet > & res, struct _test_data *exp)
{
	stringstream msg;

	cout << "#\t\t Fetching the first row, id = " << res->getInt("id");
	cout << ", label = '" << res->getString("label") << "'" << endl;

	if ((res->getInt("id") != exp->id) || (res->getString("label") != exp->label)) {
		msg.str("Wrong results");
		msg << "Expected (" << exp->id << "," << exp->label << ")";
		msg << " got (" << res->getInt("id") <<", " << res->getString("label") << ")";
		throw runtime_error(msg.str());
	}
}

static void validateResultSet(std::auto_ptr< sql::ResultSet > & res, struct _test_data *min, struct _test_data *max) {

	size_t row;

	cout << "#\t Selecting in ascending order but fetching in descending (reverse) order" << endl;
	/* Move the cursor after the last row - n + 1 */
	res->afterLast();
	if (true != res->isAfterLast())
		throw runtime_error("Position should be after last row (1)");

	row = res->rowsCount() - 1;
	/* Move the cursor backwards to: n, n - 1, ... 1, 0. Return true if rows are available. */
	while (res->previous()) {
		cout << "#\t\t Row " << row << " id = " << res->getInt("id");
		cout << ", label = '" << res->getString("label") << "'" << endl;
		row--;
	}
	/*
	The last call to res->previous() has moved the cursor before the first row
	Cursor position is 0, recall: rows are from 1 ... n
	*/
	cout << "#\t\t isBeforeFirst() = " << res->isBeforeFirst() << endl;
	cout << "#\t\t isFirst() = " << res->isFirst() << endl;
	if (!res->isBeforeFirst()) {
		throw runtime_error("Cursor should be positioned before the first row");
	}
	/* Move the cursor forward again to position 1 - the first row */
	res->next();
	cout << "#\t Positioning cursor to 1 using next(), isFirst() = " << res->isFirst() << endl;
	validateRow(res, min);
	/* Move the cursor to position 0 = before the first row */
	if (false != res->absolute(0)) {
		throw runtime_error("Call did not fail although its not allowed to move the cursor before the first row");
	}
	cout << "#\t Positioning before first row using absolute(0), isFirst() = " << res->isFirst() << endl;
	/* Move the cursor forward to position 1 = the first row */
	res->next();
	validateRow(res, min);

	/* Move the cursor to position 0 = before the first row */
	res->beforeFirst();
	cout << "#\t Positioning cursor using beforeFirst(), isFirst() = " << res->isFirst() << endl;
	/* Move the cursor forward to position 1 = the first row */
	res->next();
	cout << "#\t\t Moving cursor forward using next(), isFirst() = " << res->isFirst() << endl;
	validateRow(res, min);

	cout << "#\t Finally, reading in descending (reverse) order again" << endl;
	/* Move the cursor after the last row - n + 1 */
	res->afterLast();
	row = res->rowsCount() - 1;
	/* Move the cursor backwards to: n, n - 1, ... 1, 0. Return true if rows are available.*/
	while (res->previous()) {
		cout << "#\t\t Row " << row << ", getRow() " << res->getRow();
		cout << " id = " << res->getInt("id");
		cout << ", label = '" << res->getString("label") << "'" << endl;
		row--;
	}
	/*
	The last call to res->previous() has moved the cursor before the first row
	Cursor position is 0, recall: rows are from 1 ... n
	*/
	cout << "#\t\t isBeforeFirst() = " << res->isBeforeFirst() << endl;
	if (true != res->isBeforeFirst()) {
		throw runtime_error("Position should be 0 = before first row");
	}

	cout << "#\t And in regular order..." << endl;
	res->beforeFirst();
	if (true != res->isBeforeFirst()) {
		throw runtime_error("Cursor should be positioned before the first row");
	}
	row = 0;
	while (res->next()) {
		cout << "#\t\t Row " << row << ", getRow() " << res->getRow();
		cout << " id = " << res->getInt("id");
		cout << ", label = '" << res->getString("label") << "'" << endl;
		row++;
	}
	cout << "#\t\t isAfterLast() = " << res->isAfterLast() << endl;
	if (true != res->isAfterLast()) {
		throw runtime_error("next() has returned false and the cursor should be after the last row");
	}
	/* Move to the last entry using a negative offset for absolute() */
	cout << "#\t Trying absolute(-1) to fetch last entry..." << endl;
	if (true != res->absolute(-1)) {
		throw runtime_error("Call did fail although -1 is valid");
	}
	cout << "#\t\t isAfterLast() = " << res->isAfterLast() << endl;
	if (false != res->isAfterLast()) {
		throw runtime_error("Cursor should be positioned to the last row and not after the last row");
	}
	cout << "#\t\t isLast() = " << res->isLast() << endl;
	if (true != res->isLast()) {
		throw runtime_error("Cursor should be positioned to the last row");
	}
	validateRow(res, max);
	/* Another way to move after the last entry */
	cout << "#\t Trying absolute(NUMROWS + 10) to move cursor after last row and fetch last entry..." << endl;
	if (false != res->absolute(res->rowsCount() + 10)) {
		throw runtime_error("Call did fail although parameter is valid");
	}
	if (true != res->isAfterLast()) {
		throw runtime_error("Cursor should be positioned after the last row");
	}
	cout << "#\t\t isLast() = " << res->isLast() << endl;
	if (false != res->isLast()) {
		throw runtime_error("Cursor should be positioned after the last row");
	}
	try {
		res->getString(1);
		throw runtime_error("Fetching is possible although cursor is out of range");
	} catch (sql::InvalidArgumentException &) {
		cout << "#\t\t OK, fetching not allowed when cursor is out of range..." << endl;
	}
	/* absolute(NUM_ROWS + 10) is internally aligned to NUM_ROWS + 1 = afterLastRow() */
	res->previous();
	validateRow(res, max);
}