/*
    * 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.myfaces.tobago.internal.layout;
  
  import org.apache.myfaces.tobago.layout.LayoutBase;
  import org.apache.myfaces.tobago.layout.LayoutBox;
  import org.apache.myfaces.tobago.layout.LayoutComponent;
  import org.apache.myfaces.tobago.layout.LayoutContainer;
  import org.apache.myfaces.tobago.layout.Measure;
  import org.apache.myfaces.tobago.layout.Orientation;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.faces.component.UIComponent;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.StringTokenizer;
  import java.util.regex.Pattern;
  
  public final class LayoutUtils {
  
    private static final Logger LOG = LoggerFactory.getLogger(LayoutUtils.class);
  
    private static final Pattern TOKEN_PATTERN = Pattern.compile("^(\\d*px|\\d*\\*|\\d*%|auto|fixed)$");
  
    private LayoutUtils() {
      // to prevent instantiation
    }
  
    public static boolean checkTokens(String columns) {
      StringTokenizer st = new StringTokenizer(columns, ";");
      while (st.hasMoreTokens()) {
        String token = st.nextToken();
        if (!TOKEN_PATTERN.matcher(token).matches()) {
          return false;
        }
      }
      return true;
    }
  
    public static List<LayoutComponent> findLayoutChildren(LayoutContainer container) {
      List<LayoutComponent> result = new ArrayList<LayoutComponent>();
      addLayoutChildren((UIComponent) container, result);
      return result;
    }
  
    private static void addLayoutChildren(UIComponent component, List<LayoutComponent> result) {
      for (UIComponent child : component.getChildren()) {
        if (child instanceof LayoutComponent) {
          result.add((LayoutComponent) child);
        } else {
          // Child seems to be transparent for layout, like UIForm. 
          // So we try to add the inner components.
          addLayoutChildren(child, result);
        }
      }
    }
  
    public static Measure getBorderEnd(Orientation orientation, LayoutBox container) {
      return orientation == Orientation.HORIZONTAL ? container.getBorderRight() : container.getBorderBottom();
    }
  
    public static Measure getBorderBegin(Orientation orientation, LayoutBox container) {
      return orientation == Orientation.HORIZONTAL ? container.getBorderLeft() : container.getBorderTop();
    }
  
    public static Measure getPaddingEnd(Orientation orientation, LayoutBox container) {
      return orientation == Orientation.HORIZONTAL ? container.getPaddingRight() : container.getPaddingBottom();
    }
  
    public static Measure getPaddingBegin(Orientation orientation, LayoutBox container) {
      return orientation == Orientation.HORIZONTAL ? container.getPaddingLeft() : container.getPaddingTop();
    }
  
    public static Measure getCurrentSize(Orientation orientation, LayoutBase component) {
      return orientation == Orientation.HORIZONTAL ? component.getCurrentWidth() : component.getCurrentHeight();
    }
  
    public static void setCurrentSize(Orientation orientation, LayoutBase component, Measure size) {
      if (orientation == Orientation.HORIZONTAL) {
        final Measure width = component.getWidth();
        if (width != null) { // to not override set sizes
         size = width;
       } else {
         final Measure maximumWidth = component.getMaximumWidth();
         if (size.greaterThan(maximumWidth)) {
           size = maximumWidth;
         }
         final Measure minimumWidth = component.getMinimumWidth();
         if (size.lessThan(minimumWidth)) {
           size = minimumWidth;
         }
       }
       component.setCurrentWidth(size);
     } else {
       final Measure height = component.getHeight();
       if (height != null) { // to not override set sizes
         size = height;
       } else {
         final Measure maximumHeight = component.getMaximumHeight();
         if (size.greaterThan(maximumHeight)) {
           size = maximumHeight;
         }
         final Measure minimumHeight = component.getMinimumHeight();
         if (size.lessThan(minimumHeight)) {
           size = minimumHeight;
         }
       }
       component.setCurrentHeight(size);
     }
   }
 }