package jdepend.framework;

import java.io.*;
import java.util.*;

/**
 * The <code>PackageFilter</code> class is used to filter imported 
 * package names.
 * <p>
 * The default filter contains any packages declared in the
 * <code>jdepend.properties</code> file, if such a file exists 
 * either in the user's home directory or somewhere in the classpath.
 * 
 * @author <b>Mike Clark</b>
 * @author Clarkware Consulting, Inc.
 */

public class PackageFilter {

    private Collection filtered;

    /**
     * Constructs a <code>PackageFilter</code> instance containing 
     * the filters specified in the <code>jdepend.properties</code> file, 
     * if it exists.
     */
    public PackageFilter() {
        this(new ArrayList());
        PropertyConfigurator config = new PropertyConfigurator();
        addPackages(config.getFilteredPackages());
    }

    /**
     * Constructs a <code>PackageFilter</code> instance containing 
     * the filters contained in the specified file.
     * 
     * @param f Property file.
     */
    public PackageFilter(File f) {
        this(new ArrayList());
        PropertyConfigurator config = new PropertyConfigurator(f);
        addPackages(config.getFilteredPackages());
    }

    /**
     * Constructs a <code>PackageFilter</code> instance with the 
     * specified collection of package names to filter.
     * 
     * @param packageNames Package names to filter.
     */
    public PackageFilter(Collection packageNames) {
        filtered = new ArrayList();
        addPackages(packageNames);
    }

    /**
     * Returns the collection of filtered package names.
     * 
     * @return Filtered package names.
     */
    public Collection getFilters() {
        return filtered;
    }

    /**
     * Indicates whether the specified package name passes this package filter.
     * 
     * @param packageName Package name.
     * @return <code>true</code> if the package name should be included;
     *         <code>false</code> otherwise.
     */
    public boolean accept(String packageName) {
        for (Iterator i = getFilters().iterator(); i.hasNext();) {
            String nameToFilter = (String)i.next();
            if (packageName.startsWith(nameToFilter)) {
                return false;
            }
        }

        return true;
    }

    public void addPackages(Collection packageNames) {
        for (Iterator i = packageNames.iterator(); i.hasNext();) {
            addPackage((String)i.next());
        }
    }

    public void addPackage(String packageName) {
        if (packageName.endsWith("*")) {
            packageName = packageName.substring(0, packageName.length() - 1);
        }

        if (packageName.length() > 0) {
            getFilters().add(packageName);
        }
    }
}