/**
 * Copyright (C) 2016 Red Hat, Inc. and/or its affiliates.
 *
 * 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.jboss.errai.ioc.util;

import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;

import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.impl.gwt.GWTClass;
import org.jboss.errai.codegen.util.CDIAnnotationUtils;

import com.google.gwt.core.ext.typeinfo.NotFoundException;
import com.google.gwt.core.ext.typeinfo.TypeOracle;

/**
 * Contains utility methods for processing annotations that reference clinet-side classes that can't be deployed to the
 * server.
 *
 * @author Max Barkley <mbarkley@redhat.com>
 */
public class TranslatableAnnotationUtils {

  public static Iterable<MetaClass> getTranslatableQualifiers(final TypeOracle oracle) {
    final Set<Class<?>> typesAnnotatedWith = CDIAnnotationUtils.getQualifiersAsClasses();

    final Iterator<Class<?>> iter = typesAnnotatedWith.iterator();

    return () -> {
      return new Iterator<MetaClass>() {
        private MetaClass next;

        @Override
        public MetaClass next() {
          if (hasNext()) {
            final MetaClass retVal = next;
            next = null;

            return retVal;
          }
          else {
            throw new NoSuchElementException();
          }
        }

        @Override
        public boolean hasNext() {
          if (next == null) {
            while (iter.hasNext()) {
              final Class<?> aClass = iter.next();
              try {
                next = GWTClass.newInstance(oracle, oracle.getType(aClass.getName()));
                break;
              } catch (NotFoundException e) {
              }
            }
          }

          return next != null;
        }
      };
    };
  }

}