/*
 * Copyright (C) 2019-2022 LitterBox contributors
 *
 * This file is part of LitterBox.
 *
 * LitterBox 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.
 *
 * LitterBox 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 LitterBox. If not, see <http://www.gnu.org/licenses/>.
 */
package de.uni_passau.fim.se2.litterbox.analytics.bugpattern;

import de.uni_passau.fim.se2.litterbox.analytics.AbstractIssueFinder;
import de.uni_passau.fim.se2.litterbox.analytics.IssueSeverity;
import de.uni_passau.fim.se2.litterbox.analytics.IssueType;
import de.uni_passau.fim.se2.litterbox.ast.model.ActorDefinition;
import de.uni_passau.fim.se2.litterbox.ast.model.extensions.pen.PenDownStmt;
import de.uni_passau.fim.se2.litterbox.ast.model.extensions.pen.PenStmt;
import de.uni_passau.fim.se2.litterbox.ast.model.extensions.pen.PenUpStmt;
import de.uni_passau.fim.se2.litterbox.ast.visitor.PenExtensionVisitor;

/**
 * Scripts of a sprite using a pen up block but never a pen down block fall in this category.
 * We assume that this is a bug, because either the sprite is supposed to draw
 * something and does not, or later additions of pen down blocks may not lead to the desired results since remaining
 * pen up blocks could disrupt the project.
 */
public class MissingPenDown extends AbstractIssueFinder implements PenExtensionVisitor {

    public static final String NAME = "missing_pen_down";

    private boolean penUpSet = false;
    private boolean penDownSet = false;
    private boolean addComment;

    @Override
    public void visit(ActorDefinition actor) {
        penUpSet = false;
        penDownSet = false;
        addComment = false;
        currentActor = actor;
        visitChildren(actor);

        if (getResult()) {
            addComment = true;
            visitChildren(actor);
            reset();
        }
    }

    void reset() {
        penUpSet = false;
        penDownSet = false;
        addComment = false;
    }

    boolean getResult() {
        return !penDownSet && penUpSet;
    }

    @Override
    public String getName() {
        return NAME;
    }

    @Override
    public IssueType getIssueType() {
        return IssueType.BUG;
    }

    @Override
    public void visit(PenStmt node) {
        node.accept((PenExtensionVisitor) this);
    }

    @Override
    public void visitParentVisitor(PenStmt node) {
        visitDefaultVisitor(node);
    }

    @Override
    public void visit(PenDownStmt node) {
        if (!addComment) {
            penDownSet = true;
            visitChildren(node);
        }
    }

    @Override
    public void visit(PenUpStmt node) {
        if (!addComment) {
            penUpSet = true;
            visitChildren(node);
        } else if (getResult()) {
            addIssue(node, node.getMetadata(), IssueSeverity.MEDIUM);
        }
    }

}
