/*
 * Copyright 2009 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.safehtml.rebind;

import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.Generator.RunsLocal;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.NotFoundException;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;

import java.io.PrintWriter;

/**
 * Generator for implementations of
 * {@link com.google.gwt.safehtml.client.SafeHtmlTemplates}.
 */
@RunsLocal
public class SafeHtmlTemplatesGenerator extends Generator {

  @Override
  public String generate(TreeLogger logger, GeneratorContext genCtx,
      String fqInterfaceName) throws UnableToCompleteException {
    TypeOracle oracle = genCtx.getTypeOracle();
    JClassType interfaceType;
    try {
      interfaceType = oracle.getType(fqInterfaceName);
    } catch (NotFoundException e) {
      logger.log(TreeLogger.ERROR, "Unexpected error: " + e.getMessage(), e);
      throw new UnableToCompleteException();
    }

    String implName = interfaceType.getName();
    implName = implName.replace('.', '_') + "Impl";

    String packageName = interfaceType.getPackage().getName();
    PrintWriter printWriter = genCtx.tryCreate(logger, packageName, implName);

    if (printWriter != null) {
      ClassSourceFileComposerFactory factory =
          new ClassSourceFileComposerFactory(packageName, implName);
      factory.addImplementedInterface(interfaceType.getQualifiedSourceName());
      SourceWriter sourceWriter =
          factory.createSourceWriter(genCtx, printWriter);

      SafeHtmlTemplatesImplCreator implCreator =
          new SafeHtmlTemplatesImplCreator(sourceWriter, interfaceType);
      implCreator.emitClass(logger, null);

      genCtx.commit(logger, printWriter);
    }
    return packageName + "." + implName;
  }
}