//   Copyright 2012 Georg-August-Universität Göttingen, Germany
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

package de.ugoe.cs.autoquest.usability.rules.patterns;

import java.util.List;

import org.apache.commons.lang.StringUtils;

import com.google.common.base.Splitter;
import com.google.common.collect.Lists;

import de.ugoe.cs.autoquest.eventcore.IEventType;
import de.ugoe.cs.autoquest.eventcore.StringEventType;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IEventTask;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IIteration;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IOptional;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ISelection;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ISequence;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITask;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskVisitor;
import de.ugoe.cs.autoquest.usability.taskmodel.filter.types.EventTypeFilter;
import de.ugoe.cs.autoquest.usability.taskmodel.filter.types.TaskTypeFilter;

/**
 * <p>
 * TODO comment
 * </p>
 * 
 * @author Alexander Deicke
 */
public abstract class InteractionPatternVisitor implements ITaskVisitor {

    protected TaskTypeFilter taskType;

    protected EventTypeFilter eventType;

    protected InteractionPattern containedPattern;

    protected boolean present = false;

    protected List<ITask> retainedSelectionTasks = Lists.newArrayList();

    /*
     * (non-Javadoc)
     * 
     * @see
     * de.ugoe.cs.autoquest.tasktrees.treeifc.NodeVisitor#visit(de.ugoe.cs.autoquest.tasktrees.treeifc
     * .IEventTask)
     */
    public void visit(IEventTask event) {
        if (!this.present && isEventVisitor()) {
            IEventType eventType = event.getEventType();
            if (eventType instanceof StringEventType) {
                this.present = eventType.toString().equals(nameOfEventType());
            }
            else {
                this.present = eventType.getClass().equals(this.eventType.clazz());
            }
        }
    }

    public boolean isEventVisitor() {
        return this.eventType != null && this.containedPattern == null;
    }

    protected String nameOfEventType() {
        String ret = StringUtils.EMPTY;
        Iterable<String> splitted = Splitter.on("_").split(this.eventType.name());
        for (String str : splitted) {
            str = str.toLowerCase();
            ret += Character.toString(str.charAt(0)).toUpperCase() + str.substring(1);
        }
        return ret;
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * de.ugoe.cs.autoquest.tasktrees.treeifc.TaskVisitor#accept(de.ugoe.cs.autoquest.tasktrees.
     * treeifc.ITask)
     */
    @Override
    public void visit(ITask task) {
        if (task instanceof ISequence) {
            this.visit((ISequence) task);
        }
        else if (task instanceof IIteration) {
            this.visit((IIteration) task);
        }
        else if (task instanceof ISelection) {
            this.visit((ISelection) task);
        }
        else {
            this.visit((IOptional) task);
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * de.ugoe.cs.autoquest.tasktrees.treeifc.NodeVisitor#visit(de.ugoe.cs.autoquest.tasktrees.treeifc
     * .ISelection)
     */
    public void visit(ISelection selection) {
        if (isEventVisitor()) {
            retainNodesWherePatternIsPresent(selection);
            this.present = patternIsPresent();
        }
        else {
            this.present = containedPattern.containedIn(selection);
        }
    }

    @SuppressWarnings("unchecked")
    protected void retainNodesWherePatternIsPresent(ISelection selection) {
        for (ITask task : selection.getChildren()) {
            this.present = false;
            task.accept(this);
            if (this.present && this.taskType.filterPredicate().apply(selection)) {
                this.retainedSelectionTasks.add(selection);
            }
            if (this.present) {
                break;
            }
        }
    }

    private boolean patternIsPresent() {
        return !this.retainedSelectionTasks.isEmpty();
    }

    /**
     * <p>
     * TODO: comment
     * </p>
     * 
     * @return
     */
    public boolean isPresent() {
        return this.present;
    }

    /**
     * <p>
     * TODO: comment
     * </p>
     * 
     */
    public void reset() {
        this.retainedSelectionTasks.clear();
        this.present = false;
    }

    /**
     * <p>
     * TODO: comment
     * </p>
     * 
     * @return
     */
    public boolean hasExcludedSelectionNodes() {
        return patternIsPresent();
    }

    /**
     * <p>
     * TODO: comment
     * </p>
     * 
     * @return
     */
    public List<ITask> getRetainedSelectionNodes() {
        return this.retainedSelectionTasks;
    }

}
