/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2020, Arnaud Roques
 *
 * Project Info:  http://plantuml.com
 * 
 * If you like this project or if you find it useful, you can support us at:
 * 
 * http://plantuml.com/patreon (only 1$ per month!)
 * http://plantuml.com/paypal
 * 
 * This file is part of PlantUML.
 *
 * PlantUML 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.
 *
 * PlantUML 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 *
 * Original Author:  Arnaud Roques
 * 
 *
 */
package net.sourceforge.plantuml.command;

import net.sourceforge.plantuml.LineLocation;
import net.sourceforge.plantuml.StringLocated;
import net.sourceforge.plantuml.command.regex.IRegex;
import net.sourceforge.plantuml.command.regex.RegexResult;
import net.sourceforge.plantuml.core.Diagram;
import net.sourceforge.plantuml.error.PSystemError;

public abstract class SingleLineCommand2<S extends Diagram> implements Command<S> {

	private final IRegex pattern;
	private final boolean doTrim;
	
	public SingleLineCommand2(IRegex pattern) {
		this(true, pattern);
	}

	public SingleLineCommand2(boolean doTrim, IRegex pattern) {
		this.doTrim = doTrim;
		if (pattern == null) {
			throw new IllegalArgumentException();
		}
		this.pattern = pattern;
	}

	public boolean syntaxWithFinalBracket() {
		return false;
	}

	public String[] getDescription() {
		return new String[] { pattern.getClass().getName() };
	}

	private String myTrim(StringLocated s) {
		if (doTrim) {
			return s.getTrimmed().getString();
		}
		return s.getString();
	}

	private StringLocated myTrim2(StringLocated s) {
		if (doTrim) {
			return s.getTrimmed();
		}
		return s;
	}

	final public CommandControl isValid(BlocLines lines) {
		if (lines.size() == 2 && syntaxWithFinalBracket()) {
			return isValidBracket(lines);
		}
		if (lines.size() != 1) {
			return CommandControl.NOT_OK;
		}
		if (isCommandForbidden()) {
			return CommandControl.NOT_OK;
		}
		final StringLocated line2 = myTrim2(lines.getFirst499());
		if (syntaxWithFinalBracket() && line2.getString().endsWith("{") == false) {
			final String vline = lines.get499(0).getString() + " {";
			if (isValid(BlocLines.singleString(vline)) == CommandControl.OK) {
				return CommandControl.OK_PARTIAL;
			}
			return CommandControl.NOT_OK;
		}
		final boolean result = pattern.match(line2);
		if (result) {
			actionIfCommandValid();
		}
		return result ? CommandControl.OK : CommandControl.NOT_OK;
	}

	private CommandControl isValidBracket(BlocLines lines) {
		assert lines.size() == 2;
		assert syntaxWithFinalBracket();
		if (myTrim(lines.get499(1)).equals("{") == false) {
			return CommandControl.NOT_OK;
		}
		final String vline = lines.get499(0).getString() + " {";
		return isValid(BlocLines.singleString(vline));
	}

	protected boolean isCommandForbidden() {
		return false;
	}

	protected void actionIfCommandValid() {
	}

	public final CommandExecutionResult execute(S system, BlocLines lines) {
		if (syntaxWithFinalBracket() && lines.size() == 2) {
			assert myTrim(lines.get499(1)).equals("{");
			lines = BlocLines.singleString(lines.getFirst499().getString() + " {");
		}
		if (lines.size() != 1) {
			throw new IllegalArgumentException();
		}
		final StringLocated first = lines.getFirst499();
		final String line = myTrim(first);
		if (isForbidden(line)) {
			return CommandExecutionResult.error("Syntax error: " + line);
		}

		final RegexResult arg = pattern.matcher(line);
		if (arg == null) {
			return CommandExecutionResult.error("Cannot parse line " + line);
		}
		if (system instanceof PSystemError) {
			return CommandExecutionResult.error("PSystemError cannot be cast");
		}
		// System.err.println("lines="+lines);
		// System.err.println("pattern="+pattern.getPattern());
		return executeArg(system, first.getLocation(), arg);
	}

	protected boolean isForbidden(CharSequence line) {
		return false;
	}

	protected abstract CommandExecutionResult executeArg(S system, LineLocation location, RegexResult arg);

}
