/**

  * SQL-DK

  * Copyright © 2013 František Kučera (frantovo.cz)

  *

  * 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 info.globalcode.sql.dk;

 import static info.globalcode.sql.dk.Functions.notNull;

 import static info.globalcode.sql.dk.Functions.escapeRegEx;

 import static info.globalcode.sql.dk.Functions.findByName;

 import java.sql.Connection;

 import java.sql.PreparedStatement;

 import java.sql.SQLException;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 /**

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public class SQLCommandNamed extends SQLCommand {

 	private static final String PROBLEM_MARK = "<OMG>";

 	private String namePrefix;

 	private String nameSuffix;

 	private List<NamedParameter> parameters;

 	private List<NamedParameter> parametersUsed = new ArrayList<>();

 	private StringBuilder updatedQuery;

 	private Pattern pattern;

 	public SQLCommandNamed(String query, List<NamedParameter> parameters, String namePrefix, String nameSuffix) {

 		super(query);

 		this.updatedQuery = new StringBuilder(query.length());

 		this.parameters = parameters;

 		this.namePrefix = namePrefix;

 		this.nameSuffix = nameSuffix;

 	}

 	@Override

 	public PreparedStatement prepareStatement(Connection c) throws SQLException {

 		buildPattern();

 		placeParametersAndUpdateQuery();

 		return c.prepareStatement(updatedQuery.toString());

 	}

 	@Override

 	public void parametrize(PreparedStatement ps) throws SQLException {

 		int i = 1;

 		for (Parameter p : notNull(parametersUsed)) {

 			ps.setObject(i++, p.getValue(), p.getType());

 		}

 	}

 	/**

 	 * Builds a regexp pattern that matches all parameter names (with prefix/suffix) and which has

 	 * one group: parameter name (without prefix/suffix)

 	 */

 	private void buildPattern() {

 		StringBuilder patternString = new StringBuilder();

 		patternString.append(escapeRegEx(namePrefix));

 		patternString.append("(");

 		for (int i = 0; i < parameters.size(); i++) {

 			patternString.append(escapeRegEx(parameters.get(i).getName()));

 			if (i < parameters.size()) {

 				patternString.append("|");

 			}

 		}

 		patternString.append(")");

 		patternString.append(escapeRegEx(nameSuffix));

 		pattern = Pattern.compile(patternString.toString());

 	}

 	private void placeParametersAndUpdateQuery() throws SQLException {

 		final String originalQuery = getQuery();

 		Matcher m = pattern.matcher(originalQuery);

 		int lastPosition = 0;

 		while (m.find(lastPosition)) {

 			String name = m.group(1);

 			updatedQuery.append(originalQuery.substring(lastPosition, m.start()));

 			if (name.isEmpty()) {

 				updatedQuery.append(PROBLEM_MARK);

 				updatedQuery.append(originalQuery.substring(m.end(), originalQuery.length()));

 				throw new SQLException("Named parameter (near " + PROBLEM_MARK + ") is not defined: „" + updatedQuery + "“");

 			}

 			updatedQuery.append("?");

 			parametersUsed.add(findByName(parameters, name));

 			lastPosition = m.end();

 		}

 		updatedQuery.append(originalQuery.substring(lastPosition, originalQuery.length()));

 		for (NamedParameter definedParameter : parameters) {

 			if (findByName(parametersUsed, definedParameter.getName()) == null) {

 				throw new SQLException("Parameter „" + definedParameter.getName() + "“ is defined but not used in the query: „" + originalQuery + "“");

 			}

 		}

 	}

 	@Override

 	public List<NamedParameter> getParameters() {

 		return parameters;

 	}

 }