/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.mediapackage;
  
  import org.opencastproject.util.Checksum;
  import org.opencastproject.util.IoSupport;
  import org.opencastproject.util.MimeType;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.Serializable;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.SortedSet;
  import java.util.TreeSet;
  import java.util.UUID;
  
  import javax.xml.bind.JAXBException;
  import javax.xml.bind.Marshaller;
  import javax.xml.bind.Unmarshaller;
  import javax.xml.bind.annotation.XmlAccessType;
  import javax.xml.bind.annotation.XmlAccessorType;
  import javax.xml.bind.annotation.XmlAttribute;
  import javax.xml.bind.annotation.XmlElement;
  import javax.xml.bind.annotation.XmlElementWrapper;
  import javax.xml.bind.annotation.XmlID;
  import javax.xml.bind.annotation.XmlTransient;
  
  /**
   * This class provides base functionality for media package elements.
   */
  @XmlTransient
  @XmlAccessorType(XmlAccessType.NONE)
  public abstract class AbstractMediaPackageElement implements MediaPackageElement, Serializable {
  
    /** Serial version uid */
    private static final long serialVersionUID = 1L;
  
    /** The element identifier */
    @XmlID
    @XmlAttribute(name = "id")
    protected String id = null;
  
    /** The element's type whithin the manifest: Track, Catalog etc. */
    protected Type elementType = null;
  
    /** The element's description */
    protected String description = null;
  
    /** The element's mime type, e. g. 'audio/mp3' */
    @XmlElement(name = "mimetype")
    protected MimeType mimeType = null;
  
    /** The element's type, e. g. 'track/slide' */
    @XmlAttribute(name = "type")
    protected MediaPackageElementFlavor flavor = null;
  
    /** The tags */
    @XmlElementWrapper(name = "tags")
    @XmlElement(name = "tag")
    protected SortedSet<String> tags = new TreeSet<String>();
  
    /** The element's location */
    @XmlElement(name = "url")
    protected URI uri = null;
  
    /** Size in bytes */
    @XmlElement(name = "size")
    protected Long size = null;
  
    /** The element's checksum */
    @XmlElement(name = "checksum")
    protected Checksum checksum = null;
  
   /** The parent media package */
   protected MediaPackage mediaPackage = null;
 
   /** The optional reference to other elements or series */
   @XmlAttribute(name = "ref")
   protected MediaPackageReference reference = null;
 
   /** Needed by JAXB */
   protected AbstractMediaPackageElement() {
   }
 
   /**
    * Creates a new media package element.
    *
    * @param elementType
    *          the type, e. g. Track, Catalog etc.
    * @param flavor
    *          the flavor
    * @param uri
    *          the elements location
    */
   protected AbstractMediaPackageElement(Type elementType, MediaPackageElementFlavor flavor, URI uri) {
     this(null, elementType, flavor, uri, null, null, null);
   }
 
   /**
    * Creates a new media package element.
    *
    * @param elementType
    *          the type, e. g. Track, Catalog etc.
    * @param flavor
    *          the flavor
    * @param uri
    *          the elements location
    * @param size
    *          the element size in bytes
    * @param checksum
    *          the element checksum
    * @param mimeType
    *          the element mime type
    */
   protected AbstractMediaPackageElement(Type elementType, MediaPackageElementFlavor flavor, URI uri, Long size,
           Checksum checksum, MimeType mimeType) {
     this(null, elementType, flavor, uri, size, checksum, mimeType);
   }
 
   /**
    * Creates a new media package element.
    *
    * @param id
    *          the element identifier withing the package
    * @param elementType
    *          the type, e. g. Track, Catalog etc.
    * @param flavor
    *          the flavor
    * @param uri
    *          the elements location
    * @param size
    *          the element size in bytes
    * @param checksum
    *          the element checksum
    * @param mimeType
    *          the element mime type
    */
   protected AbstractMediaPackageElement(String id, Type elementType, MediaPackageElementFlavor flavor, URI uri,
           Long size, Checksum checksum, MimeType mimeType) {
     if (elementType == null) {
       throw new IllegalArgumentException("Argument 'elementType' is null");
     }
     this.id = id;
     this.elementType = elementType;
     this.flavor = flavor;
     this.mimeType = mimeType;
     this.uri = uri;
     this.size = size;
     this.checksum = checksum;
     this.tags = new TreeSet<String>();
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setIdentifier(String)
    */
   @Override
   public void setIdentifier(String id) {
     this.id = id;
   }
 
   @Override
   public String generateIdentifier() {
     id = UUID.randomUUID().toString();
     return id;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getIdentifier()
    */
   @Override
   public String getIdentifier() {
     return id;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setTags(java.lang.String[])
    */
   @Override
   public void setTags(String[] tags) {
     this.tags = new TreeSet<String>(Arrays.asList(tags));
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#addTag(java.lang.String)
    */
   @Override
   public void addTag(String tag) {
     if (tag == null) {
       throw new IllegalArgumentException("Tag must not be null");
     }
     tags.add(tag);
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#removeTag(java.lang.String)
    */
   @Override
   public void removeTag(String tag) {
     if (tag == null) {
       return;
     }
     tags.remove(tag);
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#containsTag(java.lang.String)
    */
   @Override
   public boolean containsTag(String tag) {
     if (tag == null || tags == null) {
       return false;
     }
     return tags.contains(tag);
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#containsTag(java.util.Collection)
    */
   @Override
   public boolean containsTag(Collection<String> tags) {
     if (tags == null || tags.size() == 0) {
       return true;
     }
     for (String tag : tags) {
       if (containsTag(tag)) {
         return true;
       }
     }
     return false;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getTags()
    */
   @Override
   public String[] getTags() {
     return tags.toArray(new String[tags.size()]);
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#clearTags()
    */
   @Override
   public void clearTags() {
     if (tags != null) {
       tags.clear();
     }
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getMediaPackage()
    */
   @Override
   public MediaPackage getMediaPackage() {
     return mediaPackage;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getElementType()
    */
   @Override
   public Type getElementType() {
     return elementType;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getElementDescription()
    */
   @Override
   public String getElementDescription() {
     return (description != null) ? description : uri.toString();
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setElementDescription(String)
    */
   @Override
   public void setElementDescription(String name) {
     this.description = name;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getReference()
    */
   @Override
   public MediaPackageReference getReference() {
     return reference;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setReference(MediaPackageReference)
    */
   @Override
   public void setReference(MediaPackageReference reference) {
     this.reference = reference;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getURI()
    */
   @Override
   public URI getURI() {
     return uri;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setURI(java.net.URI)
    */
   @Override
   public void setURI(URI uri) {
     this.uri = uri;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getChecksum()
    */
   @Override
   public Checksum getChecksum() {
     return checksum;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setChecksum(org.opencastproject.util.Checksum)
    */
   @Override
   public void setChecksum(Checksum checksum) {
     this.checksum = checksum;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getMimeType()
    */
   @Override
   public MimeType getMimeType() {
     return mimeType;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setMimeType(org.opencastproject.util.MimeType)
    */
   @Override
   public void setMimeType(MimeType mimeType) {
     this.mimeType = mimeType;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setFlavor(MediaPackageElementFlavor)
    */
   @Override
   public void setFlavor(MediaPackageElementFlavor flavor) {
     this.flavor = flavor;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getFlavor()
    */
   @Override
   public MediaPackageElementFlavor getFlavor() {
     return flavor;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#getSize()
    */
   @Override
   public long getSize() {
     return size != null ? size : -1;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#setSize(long)
    */
   @Override
   public void setSize(long size) {
     this.size = size;
   }
 
   /**
    * Sets the parent media package.
    * <p>
    * <b>Note</b> This method is only used by the media package and should not be called from elsewhere.
    *
    * @param mediaPackage
    *          the parent media package
    */
   void setMediaPackage(MediaPackage mediaPackage) {
     this.mediaPackage = mediaPackage;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#referTo(
  *        org.opencastproject.mediapackage.MediaPackageElement)
    */
   @Override
   public void referTo(MediaPackageElement element) {
     referTo(new MediaPackageReferenceImpl(element));
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#referTo(
    *      org.opencastproject.mediapackage.MediaPackageReference)
    */
   @Override
   public void referTo(MediaPackageReference reference) {
     // TODO: Check reference consistency
     this.reference = reference;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#clearReference()
    */
   @Override
   public void clearReference() {
     this.reference = null;
   }
 
   /**
    * @see org.opencastproject.mediapackage.MediaPackageElement#verify()
    */
   @Override
   public void verify() throws MediaPackageException {
     // TODO: Check availability at url
     // TODO: Download (?) and check checksum
     // Checksum c = calculateChecksum();
     // if (checksum != null && !checksum.equals(c)) {
     // throw new MediaPackageException("Checksum mismatch for " + this);
     // }
     // checksum = c;
   }
 
   /**
    * @see java.lang.Comparable#compareTo(java.lang.Object)
    */
   @Override
   public int compareTo(MediaPackageElement o) {
     return uri.toString().compareTo(o.getURI().toString());
   }
 
   /**
    * @see java.lang.Object#equals(java.lang.Object)
    */
   @Override
   public boolean equals(Object obj) {
     if (!(obj instanceof MediaPackageElement)) {
       return false;
     }
     MediaPackageElement e = (MediaPackageElement) obj;
     if (mediaPackage != null && e.getMediaPackage() != null && !mediaPackage.equals(e.getMediaPackage())) {
       return false;
     }
     if (id != null && !id.equals(e.getIdentifier())) {
       return false;
     }
     if (uri != null && !uri.equals(e.getURI())) {
       return false;
     }
     return true;
   }
 
   /**
    * @see java.lang.Object#hashCode()
    */
   @Override
   public int hashCode() {
     final int prime = 31;
     int result = 1;
     result = prime * result + ((id == null) ? 0 : id.hashCode());
     result = prime * result + ((mediaPackage == null) ? 0 : mediaPackage.hashCode());
     result = prime * result + ((uri == null) ? 0 : uri.hashCode());
     return result;
   }
 
   /**
    * @see org.opencastproject.mediapackage.ManifestContributor#toManifest(org.w3c.dom.Document,
    *      org.opencastproject.mediapackage.MediaPackageSerializer)
    */
   @Override
   public Node toManifest(Document document, MediaPackageSerializer serializer) throws MediaPackageException {
     Element node = document.createElement(elementType.toString().toLowerCase());
     if (id != null) {
       node.setAttribute("id", id);
     }
 
     // Flavor
     if (flavor != null) {
       node.setAttribute("type", flavor.toString());
     }
 
     // Reference
     if (reference != null) {
       if (mediaPackage == null || !reference.matches(new MediaPackageReferenceImpl(mediaPackage))) {
         node.setAttribute("ref", reference.toString());
       }
     }
 
     // Description
     if (description != null) {
       Element descriptionNode = document.createElement("description");
       descriptionNode.appendChild(document.createTextNode(description));
       node.appendChild(descriptionNode);
     }
 
     // Tags
     if (tags.size() > 0) {
       Element tagsNode = document.createElement("tags");
       node.appendChild(tagsNode);
       for (String tag : tags) {
         Element tagNode = document.createElement("tag");
         tagsNode.appendChild(tagNode);
         tagNode.appendChild(document.createTextNode(tag));
       }
     }
 
     // Url
     Element urlNode = document.createElement("url");
     String urlValue;
     try {
       urlValue = (serializer != null) ? serializer.encodeURI(uri).toString() : uri.toString();
     } catch (URISyntaxException e) {
       throw new MediaPackageException(e);
     }
     urlNode.appendChild(document.createTextNode(urlValue));
     node.appendChild(urlNode);
 
     // MimeType
     if (mimeType != null) {
       Element mimeNode = document.createElement("mimetype");
       mimeNode.appendChild(document.createTextNode(mimeType.toString()));
       node.appendChild(mimeNode);
     }
 
     // Size
     if (size != null && size != -1) {
       Element sizeNode = document.createElement("size");
       sizeNode.appendChild(document.createTextNode(Long.toString(size)));
       node.appendChild(sizeNode);
     }
 
     // Checksum
     if (checksum != null) {
       Element checksumNode = document.createElement("checksum");
       checksumNode.setAttribute("type", checksum.getType().getName());
       checksumNode.appendChild(document.createTextNode(checksum.getValue()));
       node.appendChild(checksumNode);
     }
 
     return node;
   }
 
   /**
    * @see java.lang.Object#toString()
    */
   @Override
   public String toString() {
     String s = (description != null) ? description : uri.toString();
     return s.toLowerCase();
   }
 
   /**
    * Attention: The media package reference is not being cloned so that calling <code>getMediaPackage()</code> on the
    * clone yields null.
    */
   @Override
   public Object clone() {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     ByteArrayInputStream in = null;
     try {
       Marshaller marshaller = MediaPackageImpl.context.createMarshaller();
       marshaller.marshal(this, out);
       Unmarshaller unmarshaller = MediaPackageImpl.context.createUnmarshaller();
       in = new ByteArrayInputStream(out.toByteArray());
       // CHECKSTYLE:OFF
       // in was already parsed and is therefore save
       return unmarshaller.unmarshal(in);
       // CHECKSTYLE:ON
     } catch (JAXBException e) {
       throw new RuntimeException(e.getLinkedException() != null ? e.getLinkedException() : e);
     } finally {
       IoSupport.closeQuietly(in);
     }
   }
 
 }