/*
 * Copyright 2014 Google Inc.
 *
 * 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.google.gwt.resources.rg;

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.resources.client.impl.CustomImageResourcePrototype;
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.safehtml.shared.UriUtils;
import com.google.gwt.user.rebind.SourceWriter;
import com.google.gwt.user.rebind.StringSourceWriter;

import java.net.URL;

/**
 * Generator for {@link CustomImageResource}.
 */
public class CustomImageResourceGenerator extends AbstractResourceGenerator {

  @Override
  public String createAssignment(TreeLogger logger, ResourceContext context, JMethod method)
      throws UnableToCompleteException {
    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];

    SourceWriter sw = new StringSourceWriter();
    sw.println("new " + CustomImageResourcePrototype.class.getName() + "(");
    sw.indent();
    sw.println('"' + method.getName() + "\",");
    // We don't care about it actually working, so just use the resource URL
    sw.println(UriUtils.class.getName() + ".fromTrustedString(\"" + resource.toExternalForm() + "\")");
    sw.outdent();
    sw.print(")");

    return sw.toString();
  }
}