/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.joran.spi;

import java.util.List;

/**
 * ElementSelector extends {@link ElementPath} with matching operations such as
 * {@link #fullPathMatch(ElementPath)},
 * {@link #getPrefixMatchLength(ElementPath)} and
 * {@link #getTailMatchLength(ElementPath)}.
 *
 * <p>
 * Parts of the path may contain '*' for wildcard matching.
 *
 * @author Ceki G&uuml;lc&uuml;
 * @since 1.1.0
 */
public class ElementSelector extends ElementPath {

    public ElementSelector() {
        super();
    }

    public ElementSelector(List<String> list) {
        super(list);
    }

    /**
     * Build an elementPath from a string.
     *
     * Note that "/x" is considered equivalent to "x" and to "x/"
     *
     */
    public ElementSelector(String p) {
        super(p);
    }

    public boolean fullPathMatch(ElementPath path) {
        if (path.size() != size()) {
            return false;
        }

        int len = size();
        for (int i = 0; i < len; i++) {
            if (!equalityCheck(get(i), path.get(i))) {
                return false;
            }
        }
        // if everything matches, then the two patterns are equal
        return true;
    }

    /**
     * Returns the number of "tail" components that this pattern has in common with
     * the pattern p passed as parameter. By "tail" components we mean the
     * components at the end of the pattern.
     */
    public int getTailMatchLength(ElementPath p) {
        if (p == null) {
            return 0;
        }

        int lSize = this.partList.size();
        int rSize = p.partList.size();

        // no match possible for empty sets
        if ((lSize == 0) || (rSize == 0)) {
            return 0;
        }

        int minLen = (lSize <= rSize) ? lSize : rSize;
        int match = 0;

        // loop from the end to the front
        for (int i = 1; i <= minLen; i++) {
            String l = this.partList.get(lSize - i);
            String r = p.partList.get(rSize - i);

            if (equalityCheck(l, r)) {
                match++;
            } else {
                break;
            }
        }
        return match;
    }

    public boolean isContainedIn(ElementPath p) {
        if (p == null) {
            return false;
        }
        return p.toStableString().contains(toStableString());
    }

    /**
     * Returns the number of "prefix" components that this pattern has in common
     * with the pattern p passed as parameter. By "prefix" components we mean the
     * components at the beginning of the pattern.
     */
    public int getPrefixMatchLength(ElementPath p) {
        if (p == null) {
            return 0;
        }

        int lSize = this.partList.size();
        int rSize = p.partList.size();

        // no match possible for empty sets
        if ((lSize == 0) || (rSize == 0)) {
            return 0;
        }

        int minLen = (lSize <= rSize) ? lSize : rSize;
        int match = 0;

        for (int i = 0; i < minLen; i++) {
            String l = this.partList.get(i);
            String r = p.partList.get(i);

            if (equalityCheck(l, r)) {
                match++;
            } else {
                break;
            }
        }

        return match;
    }

    private boolean equalityCheck(String x, String y) {
        return x.equalsIgnoreCase(y);
    }

    @Override
    public boolean equals(Object o) {
        if ((o == null) || !(o instanceof ElementSelector)) {
            return false;
        }

        ElementSelector r = (ElementSelector) o;

        if (r.size() != size()) {
            return false;
        }

        int len = size();

        for (int i = 0; i < len; i++) {
            if (!equalityCheck(get(i), r.get(i))) {
                return false;
            }
        }

        // if everything matches, then the two patterns are equal
        return true;
    }

    @Override
    public int hashCode() {
        int hc = 0;
        int len = size();

        for (int i = 0; i < len; i++) {
            // make Pattern comparisons case insensitive
            // http://jira.qos.ch/browse/LBCORE-76
            hc ^= get(i).toLowerCase().hashCode();
        }
        return hc;
    }

}
