content: /*
   * 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 com.asual.lesscss.loader;
  
  import java.io.IOException;
  
  /**
   * A {@link ResourceLoader} that allows using lesscss @include in plain .css
   * files.
   * 
   * Multiple levels of nesting are achieved by combining these two actions:
   * <ol>
   * <li>When a resource is loaded all .css strings are replaced with .less</li>
   * <li>When a .less include file is requested and it does not exist, the
   * extension is changed to .css and lookup is retried.</li>
   * </ol>
   * 
   * @author Rafał Krzewski
   */
  public class CssProcessingResourceLoader implements ResourceLoader {
  
  	private final ResourceLoader delegate;
  
  	public CssProcessingResourceLoader(ResourceLoader delegate) {
  		this.delegate = delegate;
  	}
  
  	@Override
  	public boolean exists(String path) throws IOException {
  		return delegate.exists(path)
  				|| delegate.exists(path.replaceFirst("\\.less$", ".css"));
  	}
  
  	@Override
  	public String load(String path, String charset) throws IOException {
  		String content;
  		if (delegate.exists(path)) {
  			content = delegate.load(path, charset);
  		} else {
  			content = delegate.load(path.replaceFirst("\\.less$", ".css"),
  					charset);
  		}
  		return content.replaceAll("\\.css", ".less");
  	}
  }
  