//  Copyright 2004 The Apache Software Foundation
//
// 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 org.apache.tapestry.contrib.table.components;

import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;
import java.util.StringTokenizer;

import org.apache.tapestry.ApplicationRuntimeException;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.IResourceResolver;
import org.apache.tapestry.contrib.table.model.ITableColumn;
import org.apache.tapestry.contrib.table.model.ITableColumnModel;
import org.apache.tapestry.contrib.table.model.ognl.ExpressionTableColumn;
import org.apache.tapestry.contrib.table.model.simple.SimpleTableColumn;
import org.apache.tapestry.contrib.table.model.simple.SimpleTableColumnModel;
import org.apache.tapestry.util.prop.OgnlUtils;

/**
 *  A placeholder for a static methods related to the Table component
 *
 *  @since 3.0
 *  @version $Id$
 *  @author Mindbridge
 **/
public class TableUtils
{

    /**
     *  Contains strings loaded from TableStrings.properties.
     *
     **/

    private static ResourceBundle s_objStrings = null;

    /**
     *  Gets a string from the TableStrings resource bundle.
     *
     **/

    public static String format(String key, Object[] args)
    {
            synchronized (TableUtils.class) {
                if (s_objStrings == null)
                    s_objStrings = ResourceBundle.getBundle("org.apache.tapestry.contrib.table.components.TableStrings");
            }

        String pattern = s_objStrings.getString(key);

        if (args == null)
            return pattern;

        return MessageFormat.format(pattern, args);
    }

    /**
     *  Convienience method for invoking {@link #format(String, Object[])}.
     **/

    public static String getMessage(String key)
    {
        return format(key, null);
    }

    /**
     *  Convienience method for invoking {@link #format(String, Object[])}.
     **/

    public static String format(String key, Object arg)
    {
        return format(key, new Object[] { arg });
    }

    /**
     *  Convienience method for invoking {@link #format(String, Object[])}.
     **/

    public static String format(String key, Object arg1, Object arg2)
    {
        return format(key, new Object[] { arg1, arg2 });
    }

    /**
     *  Convienience method for invoking {@link #format(String, Object[])}.
     **/

    public static String format(String key, Object arg1, Object arg2, Object arg3)
    {
        return format(key, new Object[] { arg1, arg2, arg3 });
    }

    /**
     *  Generate a table column model out of the description string provided.
     *  Entries in the description string are separated by commas.
     *  Each column entry is of the format name, name:expression, 
     *  or name:displayName:expression.
     *  An entry prefixed with ! represents a non-sortable column.
     *  If the whole description string is prefixed with *, it represents
     *  columns to be included in a Form. 
     * 
     *  @param strDesc the description of the column model to be generated
     *  @param objComponent the component ordering the generation
     *  @param objColumnSettingsContainer the component containing the column settings
     *  @return a table column model based on the provided parameters
     */
    public static ITableColumnModel generateTableColumnModel(String strDesc, IComponent objComponent, IComponent objColumnSettingsContainer)
    {
        if (strDesc == null)
            return null;

        List arrColumns = new ArrayList();

        boolean bFormColumns = false;
        while (strDesc.startsWith("*"))
        {
            strDesc = strDesc.substring(1);
            bFormColumns = true;
        }

        StringTokenizer objTokenizer = new StringTokenizer(strDesc, ",");
        while (objTokenizer.hasMoreTokens())
        {
            String strToken = objTokenizer.nextToken().trim();

            if (strToken.startsWith("="))
            {
                String strColumnExpression = strToken.substring(1);
                IResourceResolver objResolver = objColumnSettingsContainer.getPage().getEngine().getResourceResolver();

                Object objColumn =
                    OgnlUtils.get(strColumnExpression, objResolver, objColumnSettingsContainer);
                if (!(objColumn instanceof ITableColumn))
                    throw new ApplicationRuntimeException(
                        format("not-a-column", objComponent.getExtendedId(), strColumnExpression));

                arrColumns.add(objColumn);
                continue;
            }

            boolean bSortable = true;
            if (strToken.startsWith("!"))
            {
                strToken = strToken.substring(1);
                bSortable = false;
            }

            StringTokenizer objColumnTokenizer = new StringTokenizer(strToken, ":");

            String strName = "";
            if (objColumnTokenizer.hasMoreTokens())
                strName = objColumnTokenizer.nextToken();

            String strExpression = strName;
            if (objColumnTokenizer.hasMoreTokens())
                strExpression = objColumnTokenizer.nextToken();

            String strDisplayName = strName;
            if (objColumnTokenizer.hasMoreTokens())
            {
                strDisplayName = strExpression;
                strExpression = objColumnTokenizer.nextToken();
            }

            ExpressionTableColumn objColumn =
                new ExpressionTableColumn(strName, strDisplayName, strExpression, bSortable);
            if (bFormColumns)
                objColumn.setColumnRendererSource(SimpleTableColumn.FORM_COLUMN_RENDERER_SOURCE);
            if (objColumnSettingsContainer != null)
                objColumn.loadSettings(objColumnSettingsContainer);

            arrColumns.add(objColumn);
        }

        return new SimpleTableColumnModel(arrColumns);
    }

}