/*
 * Copyright (C) 2016 eccentric_nz
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package me.eccentric_nz.TARDIS.database;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import me.eccentric_nz.TARDIS.TARDIS;

/**
 * Many facts, figures, and formulas are contained within the Matrix,
 * including... the companions who travel in the TARDIS.
 *
 * Companions are the Doctor's closest friends. Such people knew the Doctor's
 * "secret": that he was someone non-human who travelled in space and time in a
 * police box-shaped craft called the TARDIS.
 *
 * @author eccentric_nz
 */
public class ResultSetOccupied {

    private final TARDISDatabaseConnection service = TARDISDatabaseConnection.getInstance();
    private final Connection connection = service.getConnection();
    private final TARDIS plugin;
    private final List<Integer> data = new ArrayList<Integer>();
    private final String prefix;

    /**
     * Creates a class instance that can be used to retrieve an SQL ResultSet
     * from the travellers table.
     *
     * @param plugin an instance of the main class.
     */
    public ResultSetOccupied(TARDIS plugin) {
        this.plugin = plugin;
        this.prefix = this.plugin.getPrefix();
    }

    /**
     * Retrieves an SQL ResultSet from the travellers table. This method builds
     * an SQL query string from the parameters supplied and then executes the
     * query. Use the getters to retrieve the results.
     */
    public void resultSet() {
        Statement statement = null;
        ResultSet rs = null;
        String query = "SELECT DISTINCT tardis_id FROM " + prefix + "travellers";
        try {
            service.testConnection(connection);
            statement = connection.createStatement();
            rs = statement.executeQuery(query);
            if (rs.isBeforeFirst()) {
                while (rs.next()) {
                    data.add(rs.getInt("tardis_id"));
                }
            }
        } catch (SQLException e) {
            plugin.debug("ResultSet error for travellers table! " + e.getMessage());
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                }
                if (statement != null) {
                    statement.close();
                }
            } catch (SQLException e) {
                plugin.debug("Error closing travellers table! " + e.getMessage());
            }
        }
    }

    public List<Integer> getData() {
        return Collections.unmodifiableList(data);
    }
}