/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2023, 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 java.util.ArrayList;
import java.util.List;
import java.util.Map;

import net.sourceforge.plantuml.AbstractPSystem;
import net.sourceforge.plantuml.EmbeddedDiagram;
import net.sourceforge.plantuml.ErrorUml;
import net.sourceforge.plantuml.ErrorUmlType;
import net.sourceforge.plantuml.core.Diagram;
import net.sourceforge.plantuml.core.DiagramType;
import net.sourceforge.plantuml.core.UmlSource;
import net.sourceforge.plantuml.error.PSystemError;
import net.sourceforge.plantuml.error.PSystemErrorUtils;
import net.sourceforge.plantuml.text.StringLocated;
import net.sourceforge.plantuml.utils.BlocLines;
import net.sourceforge.plantuml.utils.LineLocation;
import net.sourceforge.plantuml.utils.StartUtils;
import net.sourceforge.plantuml.version.IteratorCounter2;

public abstract class PSystemCommandFactory extends PSystemAbstractFactory {

	private final List<Command> cmds = new ArrayList<>();

	protected abstract void initCommandsList(List<Command> cmds);

	public abstract AbstractPSystem createEmptyDiagram(UmlSource source, Map<String, String> skinParam);

	
	protected PSystemCommandFactory() {
		this(DiagramType.UML);
	}

	protected PSystemCommandFactory(DiagramType type) {
		super(type);
	}

	@Override
	final public Diagram createSystem(UmlSource source, Map<String, String> skinParam) {
		final IteratorCounter2 it = source.iterator2();
		final StringLocated startLine = it.next();
		if (StartUtils.isArobaseStartDiagram(startLine.getString()) == false)
			throw new UnsupportedOperationException();

		if (source.isEmpty()) {
			if (it.hasNext())
				it.next();

			return buildEmptyError(source, startLine.getLocation(), it.getTrace());
		}
		AbstractPSystem sys = createEmptyDiagram(source, skinParam);

		while (it.hasNext()) {
			if (StartUtils.isArobaseEndDiagram(it.peek().getString())) {
				if (sys == null)
					return null;

				final String err = sys.checkFinalError();
				if (err != null) {
					final LineLocation location = it.next().getLocation();
					return buildExecutionError(source, err, location, it.getTrace());
				}
				if (source.getTotalLineCount() == 2) {
					final LineLocation location = it.next().getLocation();
					return buildEmptyError(source, location, it.getTrace());
				}
				sys.makeDiagramReady();
				if (sys.isOk() == false)
					return null;

				return sys;
			}
			sys = executeFewLines(sys, source, it);
			if (sys instanceof PSystemError)
				return sys;

		}
		return sys;

	}

	private AbstractPSystem executeFewLines(AbstractPSystem sys, UmlSource source, final IteratorCounter2 it) {
		final Step step = getCandidate(it);
		if (step == null) {
			final ErrorUml err = new ErrorUml(ErrorUmlType.SYNTAX_ERROR, "Syntax Error?", 0, it.peek().getLocation());
			it.next();
			return PSystemErrorUtils.buildV2(source, err, null, it.getTrace());
		}

		final CommandExecutionResult result = sys.executeCommand(step.command, step.blocLines);
		if (result.isOk() == false) {
			final LineLocation location = ((StringLocated) step.blocLines.getFirst()).getLocation();
			final ErrorUml err = new ErrorUml(ErrorUmlType.EXECUTION_ERROR, result.getError(), result.getScore(),
					location);
			sys = PSystemErrorUtils.buildV2(source, err, result.getDebugLines(), it.getTrace());
		}
		if (result.getNewDiagram() != null)
			sys = result.getNewDiagram();

		return sys;

	}

	static class Step {
		final Command command;
		final BlocLines blocLines;

		Step(Command command, BlocLines blocLines) {
			this.command = command;
			this.blocLines = blocLines;
		}

	}

	private Step getCandidate(final IteratorCounter2 it) {
		final BlocLines single = BlocLines.single(it.peek());
		synchronized (cmds) {
			if (cmds.size() == 0)
				initCommandsList(cmds);
		}

		for (Command cmd : cmds) {
			final CommandControl result = cmd.isValid(single);
			if (result == CommandControl.OK) {
				it.next();
				return new Step(cmd, single);
			}
			if (result == CommandControl.OK_PARTIAL) {
				final IteratorCounter2 cloned = it.cloneMe();
				final BlocLines lines = isMultilineCommandOk(cloned, cmd);
				if (lines == null)
					continue;

				it.copyStateFrom(cloned);
				return new Step(cmd, lines);
			}
		}
		return null;
	}

	private BlocLines isMultilineCommandOk(IteratorCounter2 it, Command cmd) {
		BlocLines lines = BlocLines.create();
		int nb = 0;
		while (it.hasNext()) {
			lines = addOneSingleLineManageEmbedded2(it, lines);
			final CommandControl result = cmd.isValid(lines);
			if (result == CommandControl.NOT_OK)
				return null;

			if (result == CommandControl.OK)
				return lines;

			nb++;
			if (cmd instanceof CommandDecoratorMultine && nb > ((CommandDecoratorMultine) cmd).getNbMaxLines())
				return null;

		}
		return null;
	}

	private static BlocLines addOneSingleLineManageEmbedded2(IteratorCounter2 it, BlocLines lines) {
		final StringLocated linetoBeAdded = it.next();
		lines = lines.add(linetoBeAdded);
		if (EmbeddedDiagram.getEmbeddedType(linetoBeAdded.getTrimmed().getString()) != null) {
			int nested = 1;
			while (it.hasNext()) {
				final StringLocated s = it.next();
				lines = lines.add(s);
				if (EmbeddedDiagram.getEmbeddedType(s.getTrimmed().getString()) != null)
					// if (s.getTrimmed().getString().startsWith(EmbeddedDiagram.EMBEDDED_START))
					nested++;
				else if (s.getTrimmed().getString().equals(EmbeddedDiagram.EMBEDDED_END)) {
					nested--;
					if (nested == 0)
						return lines;
				}
			}
		}

		return lines;
	}

}