/*
 * MIT License
 *
 * Copyright (c) 2020-present Cloudogu GmbH and Contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
    
package sonia.scm.api.rest;

//~--- non-JDK imports --------------------------------------------------------

import com.google.inject.Inject;

import sonia.scm.template.Template;
import sonia.scm.template.TemplateEngine;
import sonia.scm.template.TemplateEngineFactory;

//~--- JDK imports ------------------------------------------------------------

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;

import javax.ws.rs.ext.Provider;
import sonia.scm.template.Viewable;

/**
 *
 * @author Sebastian Sdorra
 */
@Provider
public class TemplateEngineViewable implements MessageBodyWriter<Viewable>
{
  
  private final TemplateEngineFactory templateEngineFactory;

  @Inject
  public TemplateEngineViewable(TemplateEngineFactory templateEngineFactory)
  {
    this.templateEngineFactory = templateEngineFactory;
  }


  @Override
  public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
    return type.isAssignableFrom(Viewable.class);
  }

  @Override
  public long getSize(Viewable viewable, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
    return -1;
  }

  @Override
  public void writeTo(Viewable viewable, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException {
    String path = viewable.getPath();
    
    TemplateEngine engine = templateEngineFactory.getEngineByExtension(path);

    if (engine == null)
    {
      throw new IOException("could not find template engine for ".concat(path));
    }

    Template template = engine.getTemplate(path);

    if (template == null)
    {
      throw new IOException("could not find template for ".concat(path));
    }

    PrintWriter writer = new PrintWriter(entityStream);

    template.execute(writer, viewable.getContext());
    writer.flush();
  }
}
