package org.apache.archiva.web.test;

/*
 * 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.
 */

/**
 * Utility class for creating xpath expressions
 */
public class XPathExpressionUtil
{
    public static final String CONTAINS = "contains";

    public static final String AND = " and ";

    public static final String CURRENT_NODE = "./";

    public static final String PARENT_NODE = "../";

    public static final String GRANDPARENT_NODE = "../../";

    public static final String ELEMENT_ANY_LEVEL = "//";

    public static final String TABLE_COLUMN = "td";

    public static final String TABLE_ROW = "tr";

    public static final String START_NODE_TEST = "[";

    public static final String END_NODE_TEST = "]";

    public static final String ANCHOR = "a";

    public static final String IMG = "img";

    public static final String LIST = "ul";

    public static final String LINE = "li";

    public static String getList( String[] values )
    {
        String xpathExpression = "";

        if ( values.length > 0 )
        {
            xpathExpression += ELEMENT_ANY_LEVEL;
            xpathExpression += LIST;
            xpathExpression += START_NODE_TEST;

            for ( int nIndex = 0; nIndex < values.length; nIndex++ )
            {
                xpathExpression += ( ( nIndex > 0 ) ? AND : "" );
                xpathExpression += contains( LINE + position( nIndex + 1 ), values[nIndex] );
            }

            xpathExpression += END_NODE_TEST;
        }

        return xpathExpression;
    }

    /**
     * expression for acquiring an element in one of the table columns
     * 
     * @param element the node element
     * @param elementIndex column index of the element, used for skipping
     * @param columnValues the values to be matched in each column, element column is included
     * @return
     */
    public static String getColumnElement( String element, int elementIndex, String[] columnValues )
    {
        return getColumnElement( element, elementIndex, null, columnValues );
    }

    /**
     * expression for acquiring an element in one of the table columns
     * 
     * @param element the node element
     * @param elementIndex column index of the element, used for skipping
     * @param elementValue the matched element value
     * @param columnValues the values to be matched in each column, element column is included
     * @return
     */
    public static String getColumnElement( String element, int elementIndex, String elementValue, String[] columnValues )
    {
        return getColumnElement( element, elementIndex, elementValue, "TEXT", columnValues );
    }

    /**
     * expression for acquiring an element in one of the table columns
     * 
     * @param element the node element
     * @param elementIndex column index of the element, used for skipping
     * @param imageName the matched image name
     * @param columnValues the values to be matched in each column, element column is included
     * @return
     */
    public static String getImgColumnElement( String element, int elementIndex, String imageName, String[] columnValues )
    {
        return getColumnElement( element, elementIndex, imageName, IMG, columnValues );
    }

    /**
     * expression for acquiring an element in one of the table columns
     * 
     * @param element the node element
     * @param elementIndex column index of the element, used for skipping
     * @param imageName the matched image name
     * @param columnValues the values to be matched in each column, element column is included
     * @return
     */
    private static String getColumnElement( String element, int elementIndex, String elementValue,
                                            String elementValueType, String[] columnValues )
    {
        String xpathExpression = null;

        if ( ( columnValues != null ) && ( columnValues.length > 0 ) )
        {
            xpathExpression = ELEMENT_ANY_LEVEL + element;
            xpathExpression += START_NODE_TEST;

            if ( elementValue != null )
            {
                if ( "TEXT".equals( elementValueType ) )
                {
                    xpathExpression += contains( elementValue );
                    xpathExpression += ( columnValues.length > 0 ) ? AND : "";
                }
            }

            // we are two levels below the table row element ( tr/td/<element> )
            xpathExpression += matchColumns( GRANDPARENT_NODE, columnValues, elementIndex );

            xpathExpression += END_NODE_TEST;
        }

        if ( IMG.equals( elementValueType ) )
        {
            xpathExpression += "/img[contains(@src, '" + elementValue + "')]";
        }

        return xpathExpression;
    }

    /**
     * expression for acquiring the table row that matches all column values with the same order as the list
     * 
     * @param columnValues the matched list of columnValues
     * @return
     */
    public static String getTableRow( String[] columnValues )
    {
        String xpathExpression = null;

        if ( ( columnValues != null ) && ( columnValues.length > 0 ) )
        {
            xpathExpression = new String( ELEMENT_ANY_LEVEL + TABLE_ROW + START_NODE_TEST );
            xpathExpression += matchColumns( columnValues );
            xpathExpression += END_NODE_TEST;
        }

        return xpathExpression;
    }

    private static String matchColumns( String[] columnValues )
    {
        return matchColumns( columnValues, -1 );
    }

    private static String matchColumns( String[] columnValues, int skipIndex )
    {
        return matchColumns( null, columnValues, skipIndex );
    }

    private static String matchColumns( String parent, String[] columnValues, int skipIndex )
    {
        String xpathExpression = "";

        for ( int nIndex = 0; nIndex < columnValues.length; nIndex++ )
        {
            if ( ( skipIndex != nIndex ) || ( skipIndex == -1 ) )
            {
                // prepend "and" if index > 0
                xpathExpression += ( ( nIndex > 0 ) ? AND : "" );
                xpathExpression += contains( parent, TABLE_COLUMN + position( nIndex + 1 ), columnValues[nIndex] );
            }
        }

        return xpathExpression;
    }

    private static String position( int nIndex )
    {
        return new String( "[" + nIndex + "]" );
    }

    private static String contains( String parent, String element, String matchedString )
    {
        String finalElement = ( parent != null ) ? parent : "";
        finalElement += element;

        return contains( finalElement, matchedString );
    }

    private static String contains( String matchedString )
    {
        return contains( ".", matchedString );
    }

    private static String contains( String axis, String matchedString )
    {
        return new String( CONTAINS + "(" + axis + "," + "'" + matchedString + "')" );
    }

    private static String equals( String parent, String element, String matchedString )
    {
        String finalElement = ( parent != null ) ? parent : "";
        finalElement += element;

        return equals( finalElement, matchedString );
    }

    private static String equals( String axis, String matchedString )
    {
        return new String( axis + "==" + "'" + matchedString + "'" );
    }
}