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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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package org.apache.juneau.rest.staticfile;

import static org.apache.juneau.collections.JsonMap.*;
import static org.apache.juneau.http.HttpHeaders.*;
import static org.apache.juneau.http.HttpResources.*;
import static org.apache.juneau.internal.CollectionUtils.*;
import static org.apache.juneau.internal.FileUtils.*;
import static org.apache.juneau.internal.ObjectUtils.*;

import java.io.*;
import java.util.*;

import javax.activation.*;

import org.apache.http.*;
import org.apache.juneau.cp.*;
import org.apache.juneau.http.resource.*;
import org.apache.juneau.http.response.*;
import org.apache.juneau.internal.*;
import org.apache.juneau.rest.*;

/**
 * API for retrieving localized static files from either the classpath or file system.
 *
 * <p>
 * Provides the same functionality as {@link BasicFileFinder} but adds support for returning files as {@link HttpResource}
 * objects with arbitrary headers.
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrs.StaticFiles">Static files</a>
 * </ul>
 */
public class BasicStaticFiles implements StaticFiles {

   private final Header[] headers;
   private final MimetypesFileTypeMap mimeTypes;
   private final int hashCode;
   private final FileFinder fileFinder;

   /**
    * Creates a new builder for this object.
    *
    * @param beanStore The bean store to use for creating beans.
    * @return A new builder for this object.
    */
   public static StaticFiles.Builder create(BeanStore beanStore) {
      return new StaticFiles.Builder(beanStore);
   }

   /**
    * Constructor.
    *
    * @param beanStore The bean store containing injectable beans for this logger.
    */
   public BasicStaticFiles(BeanStore beanStore) {
      this(StaticFiles
         .create(beanStore)
         .type(BasicStaticFiles.class)
         .dir("static")
         .dir("htdocs")
         .cp(beanStore.getBean(ResourceSupplier.class).get().getResourceClass(), "htdocs", true)
         .cp(beanStore.getBean(ResourceSupplier.class).get().getResourceClass(), "/htdocs", true)
         .caching(1_000_000)
         .exclude("(?i).*\\.(class|properties)")
         .headers(cacheControl("max-age=86400, public"))
      );
   }

   /**
    * Constructor.
    *
    * @param builder The builder object.
    */
   public BasicStaticFiles(StaticFiles.Builder builder) {
      this.headers = builder.headers.toArray(new Header[builder.headers.size()]);
      this.mimeTypes = builder.mimeTypes;
      this.hashCode = HashCode.of(hashCode(), headers);
      this.fileFinder = builder.fileFinder.build();
   }

   /**
    * Constructor.
    *
    * <p>
    * Can be used when subclassing and overriding the {@link #resolve(String, Locale)} method.
    */
   protected BasicStaticFiles() {
      this.headers = new Header[0];
      this.mimeTypes = null;
      this.hashCode = HashCode.of(hashCode(), headers);
      this.fileFinder = null;
   }

   /**
    * Resolve the specified path.
    *
    * <p>
    * Subclasses can override this method to provide specialized handling.
    *
    * @param path The path to resolve to a static file.
    * @param locale Optional locale.
    * @return The resource, or <jk>null</jk> if not found.
    */
   @Override /* StaticFiles */
   public Optional<HttpResource> resolve(String path, Locale locale) {
      try {
         Optional<InputStream> is = getStream(path, locale);
         if (! is.isPresent())
            return empty();
         return optional(
            streamResource(is.get())
               .setHeaders(contentType(mimeTypes == null ? null : mimeTypes.getContentType(getFileName(path))))
               .addHeaders(headers)
         );
      } catch (IOException e) {
         throw new InternalServerError(e);
      }
   }

   @Override
   public int hashCode() {
      return hashCode;
   }

   @Override /* Object */
   public boolean equals(Object o) {
      return super.equals(o) && o instanceof BasicStaticFiles && eq(this, (BasicStaticFiles)o, (x,y)->eq(x.headers, y.headers));
   }

   @Override /* FileFinder */
   public Optional<InputStream> getStream(String name, Locale locale) throws IOException {
      return fileFinder.getStream(name, locale);
   }

   @Override /* FileFinder */
   public Optional<String> getString(String name, Locale locale) throws IOException {
      return fileFinder.getString(name, locale);
   }

   @Override /* Object */
   public String toString() {
      return filteredMap()
         .append("headers", headers)
         .asReadableString();
   }
}