package ch.bzz.book.data;

import ch.bzz.book.service.Config;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * data access for book entity
 * <p>
 * M151: BookDB
 *
 * @author Marcel Suter
 * @version 1.0
 * @since 2019-10-13
 */
public class BookDao {

    /**
     * TODO
     *
     * @return
     */
    public Integer count() {
        // TODO establish connection
        // TODO count books in database
        Connection connection = null;
        Integer bookCount = null;
        ResultSet resultSet = null;
        PreparedStatement prepStmt = null;          // import java.sql.PreparedStatement
        try{
            InitialContext initialContext = new InitialContext();
            DataSource dataSource = (DataSource) initialContext.lookup(Config.getProperty("jdbcRessource"));
            connection = dataSource.getConnection();

            String sqlQuery = "SELECT count(bookUUID) FROM Book";

            try {
                prepStmt = connection.prepareStatement(sqlQuery);
                resultSet = prepStmt.executeQuery();
                if (resultSet.next()) {                // resultSet contains rows
                    bookCount = resultSet.getInt(1);   // get the value of the first attribute
                }
            } catch (SQLException sqlEx) {
                sqlEx.printStackTrace();
                throw new RuntimeException();
            } finally { //schliess die connection
                try {
                    if (resultSet != null)
                        resultSet.close();
                    if (prepStmt != null)
                        prepStmt.close();
                    if (connection != null)
                        connection.close();
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                    throw new RuntimeException();
                }
            }

        } catch (NamingException nameEx) {                                    // import javax.naming.NamingException
            nameEx.printStackTrace();
            throw new RuntimeException();
        } catch (SQLException sqlEx) {                                        // import java.sql.SQLException
            sqlEx.printStackTrace();
            throw new RuntimeException();
        }

        return bookCount; // FIXME return the number of books
    }
}