/**********************************************
    * Copyright (C) 2010 Lukas Laag
    * This file is part of lib-gwt-svg.
    * 
    * libgwtsvg is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * libgwtsvg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU Lesser General Public License for more details.
   * 
   * You should have received a copy of the GNU Lesser General Public License
   * along with libgwtsvg.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.dev.svg.impl.gen;
  
  import java.net.URL;
  
  import org.vectomatic.dom.svg.OMSVGSVGElement;
  import org.vectomatic.dom.svg.ui.SVGResource;
  import org.vectomatic.dom.svg.ui.SVGResource.Validated;
  import org.vectomatic.dom.svg.utils.OMSVGParser;
  
  import com.google.gwt.core.ext.Generator;
  import com.google.gwt.core.ext.TreeLogger;
  import com.google.gwt.core.ext.UnableToCompleteException;
  import com.google.gwt.core.ext.typeinfo.JMethod;
  import com.google.gwt.dev.util.Util;
  import com.google.gwt.resources.ext.AbstractResourceGenerator;
  import com.google.gwt.resources.ext.ResourceContext;
  import com.google.gwt.resources.ext.ResourceGeneratorUtil;
  import com.google.gwt.user.rebind.SourceWriter;
  import com.google.gwt.user.rebind.StringSourceWriter;
  
  /**
   * Provides implementations of SVGResource.
   */
  public class SVGResourceGenerator extends AbstractResourceGenerator {
  
  	@Override
  	public String createAssignment(
  		TreeLogger logger, 
  		ResourceContext context,
  		JMethod method) throws UnableToCompleteException {
  
  		// Extract the SVG name from the @Source annotation
  	    URL[] resources = ResourceGeneratorUtil.findResources(logger, context, method);
  		if (resources.length != 1) {
  			logger.log(TreeLogger.ERROR, "Exactly one resource must be specified", null);
  			throw new UnableToCompleteException();
  		}
  		URL resource = resources[0];
  
  		// The SVGResource is implemented as an anonymous inner class
  		// xxx = new SVGResource() {
  		//   public OMSVGSVGElement getSvg() {
  		//     return OMSVGParser.parse("...");
  		//   }
  		// };
  		SourceWriter sw = new StringSourceWriter();
  		sw.println("new " + SVGResource.class.getName() + "() {");
  		sw.indent();
  
  		// Convenience when examining the generated code.
  		sw.println("// " + resource.toExternalForm());
  
  		sw.println("public " + OMSVGSVGElement.class.getName() + " getSvg() {");
  		sw.indent();
  		String toWrite = Util.readURLAsString(resource);
  		if (getValidated(method)) {
  			SVGValidator.validate(toWrite, resource.toExternalForm(), logger, null);
  		}
  		sw.println("return " + OMSVGParser.class.getName() + ".parse(\"" + Generator.escape(toWrite) + "\");");
  		sw.outdent();
  		sw.println("}");
  
  	    sw.println("public String getName() {");
  	    sw.indent();
  	    sw.println("return \"" + method.getName() + "\";");
  	    sw.outdent();
  	    sw.println("}");
  
  		sw.outdent();
  		sw.println("}");
  
  		return sw.toString();
  	}
  
  	private boolean getValidated(JMethod method) {
  		Validated validated = method.getAnnotation(Validated.class);
  		if (validated == null) {
  			return true;
  		} else {
  			return validated.validated();
  		}
  	}
 	
 }