/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.tools.ant.types.selectors;

import java.io.File;
import java.util.Enumeration;
import java.util.Stack;
import java.util.Vector;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.types.DataType;
import org.apache.tools.ant.types.selectors.modifiedselector.ModifiedSelector;

/**
 * This is the base class for selectors that can contain other selectors.
 *
 * @since 1.5
 */
public abstract class BaseSelectorContainer extends BaseSelector
        implements SelectorContainer {

    private Vector<FileSelector> selectorsList = new Vector<FileSelector>();

    /**
     * Default constructor.
     */
    public BaseSelectorContainer() {
    }

    /**
     * Indicates whether there are any selectors here.
     * @return true if there are selectors
     */
    public boolean hasSelectors() {
        dieOnCircularReference();
        return !(selectorsList.isEmpty());
    }

    /**
     * Gives the count of the number of selectors in this container
     * @return the number of selectors
     */
    public int selectorCount() {
        dieOnCircularReference();
        return selectorsList.size();
    }

    /**
     * Returns the set of selectors as an array.
     * @param p the current project
     * @return an array of selectors
     */
    public FileSelector[] getSelectors(Project p) {
        dieOnCircularReference();
        FileSelector[] result = new FileSelector[selectorsList.size()];
        selectorsList.copyInto(result);
        return result;
    }

    /**
     * Returns an enumerator for accessing the set of selectors.
     * @return an enumerator for the selectors
     */
    public Enumeration<FileSelector> selectorElements() {
        dieOnCircularReference();
        return selectorsList.elements();
    }

    /**
     * Convert the Selectors within this container to a string. This will
     * just be a helper class for the subclasses that put their own name
     * around the contents listed here.
     *
     * @return comma separated list of Selectors contained in this one
     */
    public String toString() {
        dieOnCircularReference();
        StringBuilder buf = new StringBuilder();
        Enumeration<FileSelector> e = selectorElements();
        while (e.hasMoreElements()) {
            buf.append(e.nextElement().toString());
            if (e.hasMoreElements()) {
                buf.append(", ");
            }
        }
        return buf.toString();
    }

    /**
     * Add a new selector into this container.
     *
     * @param selector the new selector to add
     */
    public void appendSelector(FileSelector selector) {
        selectorsList.addElement(selector);
        setChecked(false);
    }

    /**
     * <p>This implementation validates the container by calling
     * verifySettings() and then validates each contained selector
     * provided that the selector implements the validate interface.
     * </p>
     * <p>Ordinarily, this will validate all the elements of a selector
     * container even if the isSelected() method of some elements is
     * never called. This has two effects:</p>
     * <ul>
     * <li>Validation will often occur twice.
     * <li>Since it is not required that selectors derive from
     * BaseSelector, there could be selectors in the container whose
     * error conditions are not detected if their isSelected() call
     * is never made.
     * </ul>
     */
    public void validate() {
        verifySettings();
        dieOnCircularReference();
        String errmsg = getError();
        if (errmsg != null) {
            throw new BuildException(errmsg);
        }
        Enumeration<FileSelector> e = selectorElements();
        while (e.hasMoreElements()) {
            Object o = e.nextElement();
            if (o instanceof BaseSelector) {
                ((BaseSelector) o).validate();
            }
        }
    }


    /**
     * Method that each selector will implement to create their selection
     * behaviour. This is what makes SelectorContainer abstract.
     *
     * @param basedir the base directory the scan is being done from
     * @param filename the name of the file to check
     * @param file a java.io.File object for the filename that the selector
     * can use
     * @return whether the file should be selected or not
     */
    public abstract boolean isSelected(File basedir, String filename,
                                       File file);


    /* Methods below all add specific selectors */

    /**
     * add a "Select" selector entry on the selector list
     * @param selector the selector to add
     */
    public void addSelector(SelectSelector selector) {
        appendSelector(selector);
    }

    /**
     * add an "And" selector entry on the selector list
     * @param selector the selector to add
     */
    public void addAnd(AndSelector selector) {
        appendSelector(selector);
    }

    /**
     * add an "Or" selector entry on the selector list
     * @param selector the selector to add
     */
    public void addOr(OrSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a "Not" selector entry on the selector list
     * @param selector the selector to add
     */
    public void addNot(NotSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a "None" selector entry on the selector list
     * @param selector the selector to add
     */
    public void addNone(NoneSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a majority selector entry on the selector list
     * @param selector the selector to add
     */
    public void addMajority(MajoritySelector selector) {
        appendSelector(selector);
    }

    /**
     * add a selector date entry on the selector list
     * @param selector the selector to add
     */
    public void addDate(DateSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a selector size entry on the selector list
     * @param selector the selector to add
     */
    public void addSize(SizeSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a selector filename entry on the selector list
     * @param selector the selector to add
     */
    public void addFilename(FilenameSelector selector) {
        appendSelector(selector);
    }

    /**
     * add an extended selector entry on the selector list
     * @param selector the selector to add
     */
    public void addCustom(ExtendSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a contains selector entry on the selector list
     * @param selector the selector to add
     */
    public void addContains(ContainsSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a present selector entry on the selector list
     * @param selector the selector to add
     */
    public void addPresent(PresentSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a depth selector entry on the selector list
     * @param selector the selector to add
     */
    public void addDepth(DepthSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a depends selector entry on the selector list
     * @param selector the selector to add
     */
    public void addDepend(DependSelector selector) {
        appendSelector(selector);
    }

    /**
     * adds a different selector to the selector list
     * @param selector the selector to add
     */
    public void addDifferent(DifferentSelector selector) {
        appendSelector(selector);
    }

    /**
     * adds a type selector to the selector list
     * @param selector the selector to add
     */
    public void addType(TypeSelector selector) {
        appendSelector(selector);
    }

    /**
     * add a regular expression selector entry on the selector list
     * @param selector the selector to add
     */
    public void addContainsRegexp(ContainsRegexpSelector selector) {
        appendSelector(selector);
    }

    /**
     * add the modified selector
     * @param selector the selector to add
     * @since ant 1.6
     */
    public void addModified(ModifiedSelector selector) {
        appendSelector(selector);
    }

    public void addReadable(ReadableSelector r) {
        appendSelector(r);
    }

    public void addWritable(WritableSelector w) {
        appendSelector(w);
    }

    /**
     * add an arbitrary selector
     * @param selector the selector to add
     * @since Ant 1.6
     */
    public void add(FileSelector selector) {
        appendSelector(selector);
    }

    protected synchronized void dieOnCircularReference(Stack<Object> stk, Project p)
        throws BuildException {
        if (isChecked()) {
            return;
        }
        if (isReference()) {
            super.dieOnCircularReference(stk, p);
        } else {
            for (FileSelector fileSelector : selectorsList) {
                if (fileSelector instanceof DataType) {
                    pushAndInvokeCircularReferenceCheck((DataType) fileSelector, stk, p);
                }
            }
            setChecked(true);
        }
    }
}
