/**

 * 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;

	}

}