/**
 * 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.");
			}
		}
	}

	@Override
	public List<NamedParameter> getParameters() {
		return parameters;
	}
}