/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.config.spring.util;

import org.mule.runtime.core.util.IOUtils;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.UnsupportedEncodingException;

import org.springframework.core.io.AbstractResource;

/**
 * Spring 2.x is picky about open/closed input streams, as it requires a closed stream (fully read resource) to enable automatic
 * validation detection (DTD or XSD). Otherwise, a caller has to specify the mode explicitly.
 * <p/>
 * Code relying on Spring 1.2.x behavior may now break with
 * {@link org.springframework.beans.factory.BeanDefinitionStoreException}. This class is called in to remedy this and should be
 * used instead of, e.g. {@link org.springframework.core.io.InputStreamResource}.
 * <p/>
 * The resource is fully stored in memory.
 */
public class CachedResource extends AbstractResource {

  private static final String DEFAULT_DESCRIPTION = "cached in-memory resource";

  private final byte[] buffer;
  private final String description;

  public CachedResource(byte[] source) {
    this(source, null);
  }

  public CachedResource(String source, String encoding) throws UnsupportedEncodingException {
    this(source.trim().getBytes(encoding), DEFAULT_DESCRIPTION);
  }

  public CachedResource(byte[] source, String description) {
    this.buffer = source;
    this.description = description;
  }

  public CachedResource(Reader reader, String encoding) throws IOException {
    this(IOUtils.toByteArray(reader, encoding), DEFAULT_DESCRIPTION);
  }

  public String getDescription() {
    return (description == null) ? "" : description;
  }

  public InputStream getInputStream() throws IOException {
    // This HAS to be a new InputStream, otherwise SAX
    // parser breaks with 'Premature end of file at line -1"
    // This behavior is not observed with Spring pre-2.x
    return new ByteArrayInputStream(buffer);
  }
}