/*
    * 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.NotFoundException;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.io.FilenameUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.Set;
  import java.util.UUID;
  import java.util.function.BiFunction;
  import java.util.function.Function;
  import java.util.function.Predicate;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  /**
   * HLS-VOD
   *
   * This interface describes methods and fields for an adaptive manifest playlist. as defined in
   * https://tools.ietf.org/html/draft-pantos-http-live-streaming-20 This is text file which references media tracks or
   * playlists in the same mediapackage using relative path names (usual) or absolute URI. Master Playlist tags MUST NOT
   * appear in a Media Playlist; Media Segment tag MUST NOT appear in a Master Playlist.
   */
  public interface AdaptivePlaylist extends Track {
  
    /**
     * Media package element type.
     */
    // String COLLECTION = "AdaptivePlaylist";
    Logger logger = LoggerFactory.getLogger(AdaptivePlaylist.class);
  
    Pattern uriPatt = Pattern.compile("URI=\"([^\"]+)\"");
    Pattern filePatt = Pattern.compile("([a-zA-Z0-9_.\\-\\/]+)\\.(\\w+)$");
    // Known tags that references other files include the following - but we only use EXT-X-MAP here
    // "#EXT-X-MAP:", "#EXT-X-MEDIA:", "#EXT-X-I-FRAME-STREAM-INF:", "#EXT-X-SESSION-DATA:",
    // Variant tags: see Section 4.4.2 in draft
    List<String> extVariant = Arrays.asList("#EXT-X-MAP:", "#EXT-X-TARGETDURATION:", "EXTINF", "#EXT-X-BYTERANGE:");
    // Master tags: see Section 4.4.4
    List<String> extMaster = Arrays.asList("#EXT-X-MEDIA:", "#EXT-X-STREAM-INF:", "#EXT-X-I-FRAME-STREAM-INF:",
            "#EXT-X-SESSION-DATA:");
    Pattern masterPatt = Pattern.compile(String.join("|", extMaster), Pattern.CASE_INSENSITIVE);
    Pattern variantPatt = Pattern.compile(String.join("|", extVariant), Pattern.CASE_INSENSITIVE);
    Predicate<File> isHLSFilePred = f -> "m3u8".equalsIgnoreCase(FilenameUtils.getExtension(f.getName()));
    Predicate<String> isPlaylistPred = f -> "m3u8".equalsIgnoreCase(FilenameUtils.getExtension(f));
    Predicate<Track> isHLSTrackPred = f -> "m3u8".equalsIgnoreCase(FilenameUtils.getExtension(f.getURI().getPath()));
  
    static boolean isPlaylist(String filename) {
      return filename != null && isPlaylistPred.test(filename);
    }
  
    static boolean isPlaylist(File file) {
      return file != null && isHLSFilePred.test(file);
   }
 
   static boolean isPlaylist(Track track) {
     return track != null && isHLSTrackPred.test(track);
   }
 
   // Return true if any elements in a collection is a m3u8 playlist
   static boolean hasHLSPlaylist(Collection<MediaPackageElement> elements) {
     return elements.stream().filter(e -> e.getElementType() == MediaPackageElement.Type.Track)
             .anyMatch(t -> isHLSTrackPred.test((Track) t));
   }
 
   static List<Track> getSortedTracks(List<Track> files, boolean segmentsOnly) {
     List<Track> fmp4 = files;
     if (segmentsOnly) {
       fmp4 = files.stream().filter(isHLSTrackPred.negate()).collect(Collectors.toList());
     }
     fmp4.sort(Comparator.comparing(track -> FilenameUtils.getBaseName(track.getURI().getPath())));
     return fmp4;
   }
 
   /**
    * Return true if this is a master manifest (contains variants manifest and no media segments)
    *
    * @param file
    *          - media file
    * @return true if is a master manifest
    * @throws IOException
    *           if bad file
    */
   static boolean checkForMaster(File file) throws IOException {
     if (!isPlaylist(file))
       return false;
     try (Stream<String> lines = Files.lines(file.toPath())) {
       return lines.map(masterPatt::matcher).anyMatch(Matcher::find);
     }
   }
 
   /**
    * Return true if this is a variant manifest (contains media segments only)
    *
    * @param file
    *          - media file
    * @return true if is a HLS playlist but not master
    * @throws IOException
    *           if bad file - can't access or otherwise
    */
   static boolean checkForVariant(File file) throws IOException {
     if (!isPlaylist(file))
       return false;
     try (Stream<String> lines = Files.lines(file.toPath())) {
       return lines.map(variantPatt::matcher).anyMatch(Matcher::find);
     }
   }
 
   /**
    * Given a master or variant playlist/manifest - get referenced files. This does not deal with files referenced by
    * tags yet.
    *
    * @param file
    *          to parse
    * @return Set of names referenced
    * @throws IOException
    *           if can't access file
    */
   static Set<String> getVariants(File file) throws IOException {
     Set<String> files = new HashSet<String>();
     try (BufferedReader br = Files.newBufferedReader(file.toPath())) {
       files = (br.lines().map(l -> {
         if (!l.startsWith("#")) {
           Matcher m = filePatt.matcher(l);
           if (m != null && m.matches())
             return m.group(0);
         }
         return null;
       }).collect(Collectors.toSet()));
     } catch (IOException e) {
       throw new IOException("Cannot read file " + file + e.getMessage());
     }
     files.remove(null);
     return files;
   }
 
   /**
    * Given a playlist - recursively get all referenced files in the same filesystem with relative links
    *
    * @param file
    *          media file
    * @return Set of names referenced
    * @throws IOException
    *           if can't access file
    */
   static Set<String> getReferencedFiles(File file, boolean segmentsOnly) throws IOException {
     Set<String> allFiles = new HashSet<String>(); // don't include playlist variants
     Set<String> segments = getVariants(file).stream().filter(isPlaylistPred.negate())
             .collect(Collectors.toSet());
     Set<String> variants = getVariants(file).stream().filter(isPlaylistPred).collect(Collectors.toSet());
 
     if (!segmentsOnly)
       allFiles.addAll(variants); // include the playlist
     allFiles.addAll(segments);
 
     for (String f : variants) {
       try {
         new URL(f); // ignore external paths
       } catch (MalformedURLException e) {
         // is relative path - read the variant playlist
         String name = FilenameUtils.concat(FilenameUtils.getFullPath(file.getAbsolutePath()), f);
         allFiles.addAll(getReferencedFiles(new File(name), true));
       }
     }
     return allFiles;
   }
 
   /***
    * Set the path of the url as the logical name
    *
    * @param track
    *          - tag with name
    */
   static void setLogicalName(Track track) {
     track.setLogicalName(FilenameUtils.getName(track.getURI().getPath()));
   }
 
   /**
    * Set HLS Tracks references to point to immediate parent, post inspection
    *
    * @param tracks
    *          - all tracks in an HLS adaptive playlist
    * @param getFileFromURI
    *          - a way to map uri to file
    * @throws IOException
    *           if failed to read files
    */
   static void hlsSetReferences(List<Track> tracks, Function<URI, File> getFileFromURI) throws IOException {
     final Optional<Track> master = tracks.stream().filter(t -> t.isMaster()).findAny();
     final List<Track> variants = tracks.stream().filter(t -> t.getElementType() == MediaPackageElement.Type.Manifest)
             .collect(Collectors.toList());
     final List<Track> segments = tracks.stream().filter(t -> t.getElementType() != MediaPackageElement.Type.Manifest)
             .collect(Collectors.toList());
     tracks.forEach(track -> setLogicalName(track));
     if (master.isPresent())
       variants.forEach(t -> t.referTo(master.get())); // variants refer to master
     HashMap<String, Track> map = new HashMap<String, Track>();
     for (Track t : variants) {
       File f = getFileFromURI.apply(t.getURI());
       Set<String> seg = getReferencedFiles(f, true); // Find segment
       // Should be one only
       seg.forEach(s -> map.put(s, t));
     }
     segments.forEach(t -> { // segments refer to variants
       t.referTo(map.get(t.getLogicalName()));
     });
   }
 
   /**
    * Fix all the playlists locations and references based on a file map from old name to new name.
    *
    * @param hlsFiles
    *          - List of all files in a playlist including playlists
    * @param map
    *          - the mapping of the references to the actual file location
    * @return the fixed files
    * @throws IOException
    *           if failed to read files
    */
   static List<File> hlsRenameAllFiles(List<File> hlsFiles, Map<File, File> map) throws IOException {
     for (Map.Entry<File, File> entry : map.entrySet()) {
       if (entry.getKey().toPath() != entry.getValue().toPath()) { // if different
         logger.debug("Move file from " + entry.getKey() + " to " + entry.getValue());
         if (entry.getValue().exists())
           FileUtils.forceDelete(entry.getValue()); // can redo this
         FileUtils.moveFile(entry.getKey(), entry.getValue());
       }
     }
     // rename all files to new names if needed
     HashMap<String, String> nameMap = new HashMap<String, String>();
     map.forEach((k, v) -> nameMap.put(k.getName(), v.getName()));
     for (File f : map.values()) {
       if (isPlaylist(f))
         hlsRewriteFileReference(f, nameMap); // fix references
     }
     return new ArrayList<File>(map.values());
   }
 
 
   /**
    * Fix all the HLS file references in a manifest when a referenced file is renamed
    *
    * @param srcFile
    *          - srcFile to be rewritten
    * @param mapNames
    *          - mapped from old name to new name
    * @throws IOException
    *           if failed
    */
   static void hlsRewriteFileReference(File srcFile, Map<String, String> mapNames) throws IOException {
     File tmpFile = new File(srcFile.getAbsolutePath() + UUID.randomUUID() + ".tmp");
     try { // rewrite src file
       FileUtils.moveFile(srcFile, tmpFile);
       hlsRewriteFileReference(tmpFile, srcFile, mapNames); // fix references
     } catch (IOException e) {
       throw new IOException("Cannot rewrite " + srcFile + " " + e.getMessage());
     } finally {
       FileUtils.deleteQuietly(tmpFile); // delete temp file
       tmpFile = null;
     }
   }
 
   /**
    * Fix all the HLS file references in a manifest when a referenced file is renamed All the mapped files should be in
    * the same directory, make sure they are not workspace files (no md5)
    *
    * @param srcFile
    *          - source file to change
    * @param destFile
    *          - dest file to hold results
    * @param mapNames
    *          - mapping from oldName to newName
    * @throws IOException
    *           if failed
    */
   static void hlsRewriteFileReference(File srcFile, File destFile, Map<String, String> mapNames) throws IOException {
     // Many tags reference URIs - not all are dealt with in this code, eg:
     // "#EXT-X-MAP:", "#EXT-X-MEDIA:", "#EXT-X-I-FRAME-STREAM-INF:", "#EXT-X-SESSION-DATA:", "#EXT-X-KEY:",
     // "#EXT-X-SESSION-DATA:"
     try (FileWriter hlsReWriter = new FileWriter(destFile.getAbsoluteFile(), false);
          BufferedReader br = new BufferedReader(new FileReader(srcFile))) {
       String line;
       while ((line = br.readLine()) != null) {
         // https://tools.ietf.org/html/draft-pantos-http-live-streaming-20
         // Each line is a URI, blank, or starts with the character #
         if (!line.trim().isEmpty()) {
           if (line.startsWith("#")) {
             // eg: #EXT-X-MAP:URI="39003_segment_0.mp4",BYTERANGE="1325@0"
             if (line.startsWith("#EXT-X-MAP:") || line.startsWith("#EXT-X-MEDIA:")) {
               String tmpLine = line;
               Matcher matcher = uriPatt.matcher(line);
               // replace iff file is mapped
               if (matcher.find() && mapNames.containsKey(matcher.group(1))) {
                 tmpLine = line.replaceFirst(matcher.group(1), mapNames.get(matcher.group(1)));
               }
               hlsReWriter.write(tmpLine);
             } else
               hlsReWriter.write(line);
           } else {
             line = line.trim();
             String filename = FilenameUtils.getName(line);
             if (mapNames.containsKey(line)) {
               hlsReWriter.write(mapNames.get(line));
             } else if (mapNames.containsKey(filename)) {
               String newFileName = mapNames.get(FilenameUtils.getName(filename));
               String newPath = FilenameUtils.getPath(line);
               if (newPath.isEmpty())
                 hlsReWriter.write(newFileName);
               else
                 hlsReWriter.write(FilenameUtils.concat(newPath, newFileName));
             } else
               hlsReWriter.write(line);
           }
         }
         hlsReWriter.write(System.lineSeparator()); // new line
       }
     } catch (Exception e) {
       logger.error("Failed to rewrite hls references " + e.getMessage());
       throw new IOException(e);
     }
   }
 
   /**
    * Return logical name mapped to file
    *
    * @param tracks
    *          from a HLS manifest
    * @param getFileFromURI
    *          is a function to get file from an URI
    * @return names mapped to file
    */
   static Map<String, File> logicalNameFileMap(List<Track> tracks, Function<URI, File> getFileFromURI) {
     Map<String, File> nameMap = tracks.stream().collect(Collectors.<Track, String, File> toMap(
             track -> track.getLogicalName(), track -> getFileFromURI.apply(track.getURI())));
     return nameMap;
   }
 
   static Map<String, URI> logicalNameURLMap(List<Track> tracks) {
     HashMap<String, URI> nameMap = new HashMap<String, URI>();
     for (Track track : tracks) {
       nameMap.put(track.getLogicalName(), track.getURI());
     }
     return nameMap;
   }
 
   /**
    *
    * Return track urls as relative to the master playlist (only one in the list)
    *
    * @param tracks
    *          from an HLS playlist
    * @return track urls as relative to the master playlist
    */
   static HashMap<String, String> urlRelativeToMasterMap(List<Track> tracks) {
     HashMap<String, String> nameMap = new HashMap<String, String>();
     Optional<Track> master = tracks.stream().filter(t -> t.isMaster()).findAny();
     List<Track> others = tracks.stream().filter(t -> !t.isMaster()).collect(Collectors.toList());
     if (master.isPresent()) // Relativize all the files from the master playlist
       others.forEach(track -> {
         nameMap.put(track.getLogicalName(), track.getURI().relativize(master.get().getURI()).toString());
       });
     return nameMap;
   }
 
   // Representation of a track/playlist for internal use only
   class Rep {
     private Track track;
     private String name; // reference name
     private boolean isPlaylist = false;
     private boolean isMaster = false;
     private File origMpfile;
     private String newfileName;
     private URI origMpuri;
     private URI newMpuri = null;
     private String relPath;
 
     // Get file relative to the mediapackage directory
     Rep(Track track, File mpdir) throws NotFoundException, IOException {
       this.track = track;
       origMpuri = track.getURI();
       origMpfile = getFilePath(origMpuri, mpdir);
       name = FilenameUtils.getName(origMpuri.getPath()).trim();
       isPlaylist = AdaptivePlaylist.isPlaylist(track.getURI().getPath()); // check suffix
     }
 
     // Get file based on a look up, eg: workspace.get()
     Rep(Track track, Function<URI, File> getFileFromURI) {
       this.track = track;
       origMpuri = track.getURI();
       origMpfile = getFileFromURI.apply(origMpuri);
       name = FilenameUtils.getName(origMpfile.getPath());
       isPlaylist = AdaptivePlaylist.isPlaylist(track.getURI().getPath());
     }
 
     private File getFilePath(URI uri, File mpDir) {
       String mpid = mpDir.getName();
       String path = uri.getPath();
       final Matcher matcher = Pattern.compile(mpid).matcher(path);
       if (matcher.find()) {
         return new File(mpDir, path.substring(matcher.end()).trim());
       }
       // If there is no mpDir, it may be a relative path
       return new File(mpDir, path);
     }
 
     public boolean isMaster() {
       return this.track.isMaster();
     }
 
     public boolean parseForMaster() {
       try {
         setMaster(checkForMaster(origMpfile));
       } catch (IOException e) {
         logger.error("Cannot open file for check for master:{}", origMpfile);
       }
       return isMaster;
     }
 
     public void setMaster(boolean isMaster) {
       this.isMaster = isMaster;
       this.track.setMaster(isMaster);
     }
 
     @Override
     public String toString() {
       return track.toString();
     }
   }
 
   /**
    * Replace the content of a playlist file in place, use in composer only - not in workspace
    *
    * @param file
    *          as playlist
    * @param map
    *          - mapping from reference/logical name to new path
    * @return playlist with changed file names based on the map
    * @throws IOException
    *           if can't access file
    * @throws NotFoundException
    *           if file not found
    */
   static File replaceTrackFileInPlace(File file, Map<String, String> map) throws IOException, NotFoundException {
     File newFile = new File(file.getAbsolutePath() + UUID.randomUUID() + ".tmp");
     try {
       // move old file to tmp
       FileUtils.moveFile(file, newFile);
       // Write over old file with fixed references
       hlsRewriteFileReference(newFile, file, map);
     } catch (IOException e) {
       logger.error("Cannot rewrite " + file + ": " + e.getMessage());
       throw (e);
     } finally {
       FileUtils.deleteQuietly(newFile); // not needed anymore
       newFile = null;
     }
     return file;
 
   }
 
   /**
    * Find relative path to referee URL if a link is in the referer page
    *
    * @param referer
    *          - pointer to file
    * @param referee
    *          - pointee
    * @return referee path as a relative path from referer URL
    * @throws URISyntaxException
    *           if bad URI
    */
 
   static String relativize(URI referer, URI referee) throws URISyntaxException {
     URI u1 = referer.normalize();
     URI u2 = referee.normalize();
     File f = relativizeF(u1.getPath(), u2.getPath());
     return f.getPath(); // relative name to use in manifest
   }
 
   // They should all be relative paths at this point in the working file repo
   static File relativizeF(String s1, String s2) throws URISyntaxException {
     String fp = new File(s1).getParent(); // get s1 folder
     Path p2 = Paths.get(s2);
     if (fp != null) {
       Path p1 = Paths.get(fp);
       try {
         Path rp = p1.relativize(p2);
         return rp.toFile();
       } catch (IllegalArgumentException e) {
         logger.info("Not a relative path " + p1 + " to " + p2);
         return p2.toFile();
       }
     } else
       return p2.toFile();
   }
 
   /**
    * Fix the playlist references in a publication. The playlist files are replaced in place using relative link instead
    * of the filename
    *
    * @param tracks
    *          - tracks that represent a HLS playlist
    * @param mpDir
    *          - distribution media package file directory which represents the file storage of the URI used in the
    *          tracks
    * @return the tracks with the files updated
    * @throws MediaPackageException
    *           if files do not conform to HLS spec.
    * @throws NotFoundException
    *           if files are missing
    * @throws IOException
    *           if can't read
    * @throws URISyntaxException
    *           if bad URI
    */
   static List<Track> fixReferences(List<Track> tracks, File mpDir)
           throws MediaPackageException, NotFoundException, IOException, URISyntaxException {
     HashMap<String, Rep> nameMap = new HashMap<String, Rep>();
     Rep master = null;
     Rep segment = null;
     List<Track> newTracks = new ArrayList<Track>();
     if (tracks.size() < 2) {
       logger.debug("At least 2 files in an HLS distribution");
       throw new MediaPackageException("Not enough files in a playlist");
     }
     // map logical name to track representation
     for (Track track : tracks) {
       Rep rep = new Rep(track, mpDir);
       nameMap.put(track.getLogicalName(), rep); // add all to nameMap
       if (track.isMaster())
         master = rep; // track.getLogicalname();
       if (!rep.isPlaylist)
         segment = rep; // find any segment
     }
     if (segment == null) { // must have at least one segment
       throw new MediaPackageException("No playable media segment in mediapackage");
 
     }
     // Try to find master or use any playlist, if not found, throw exception
     Optional<Rep> oprep = nameMap.values().stream().filter(r -> r.parseForMaster()).findFirst();
     if (!oprep.isPresent())
       oprep = nameMap.values().parallelStream().filter(r -> r.isPlaylist).findFirst();
     oprep.orElseThrow(() -> new MediaPackageException("No playlist found, not HLS distribution"));
     master = oprep.get();
 
     HashMap<String, String> newNames = new HashMap<String, String>();
     for (String logName : nameMap.keySet()) { // map original name
       Rep rep = nameMap.get(logName);
       // segments are fixed, fix variant references to segments based on segments
       String relPath;
       if (!segment.origMpuri.equals(rep.origMpuri)) { // not itself
         relPath = relativize(segment.origMpuri, rep.origMpuri);
       } else { // only element id is different
         relPath = relativize(master.origMpuri, rep.origMpuri);
       }
       newNames.put(logName, relPath);
     }
     // on variant playlists, rewrite references to segments
     for (String logName : nameMap.keySet()) {
       Rep rep = nameMap.get(logName);
       if (rep == master) // deal with master later
         continue;
       if (!rep.isPlaylist) {
         newTracks.add(rep.track); // segments are unchanged
         continue;
       }
       replaceTrackFileInPlace(rep.origMpfile, newNames);
       rep.newMpuri = rep.origMpuri;
       newTracks.add(rep.track); // add changed variants
     }
     // remap logical name to the new id for the variant files from above
     for (String logName : nameMap.keySet()) {
       Rep rep = nameMap.get(logName);
       if (!rep.isPlaylist || rep == master)
         continue;
       String relPath = relativize(segment.origMpuri, rep.newMpuri);
       newNames.put(logName, relPath);
     }
     // on master, fix references to variant playlists
     replaceTrackFileInPlace(master.origMpfile, newNames);
     master.newMpuri = master.track.getURI();
     newTracks.add(master.track);
     // Update the logical names to keep referential integrity
     for (Track track : newTracks) {
       String newpath = newNames.get(track.getLogicalName());
       if (newpath != null && track != master) // no file refers to master
         track.setLogicalName(newpath);
     }
     newNames = null;
     return newTracks;
   }
 
   /**
    * Fix HLS playlists/media already in the workspace as the result of an ingest This builds the hierarchies of a HLS
    * playlist with masters as the roots. This is useful if mixed files are ingested into a mediapackage. HLS files with
    * relative links will fail in an inspection unless the relative paths are fixed. Logical names should be preserved if
    * they exists.
    */
   class HLSMediaPackageCheck {
     private HashMap<String, String> fileMap = new HashMap<String, String>();
     private HashMap<String, Rep> repMap = new HashMap<String, Rep>();;
     private List<Rep> reps;
     private List<Rep> playlists;
     private List<Rep> segments;
     private List<Rep> masters = new ArrayList<Rep>();
 
     /**
      * Builds a map of files in the mediapackage so that it can be analyzed and fixed if needed
      *
      * @param tracks
      *          - list of tracks from a media package
      * @param getFileFromURI
      *          - a function to get files from the media package by URI
      * @throws IOException
      *           if can't read file
      * @throws URISyntaxException
      *           if bad URI
      * @throws MediaPackageException
      *           - if mediapackage is incomplete and missing segments
      */
     public HLSMediaPackageCheck(List<Track> tracks, Function<URI, File> getFileFromURI)
             throws IOException, MediaPackageException, URISyntaxException {
       this.reps = tracks.stream().map(t -> new Rep(t, getFileFromURI)).collect(Collectors.toList());
       for (Rep rep : reps)
         repMap.put(rep.name, rep);
       this.playlists = reps.stream().filter(r -> r.isPlaylist).collect(Collectors.toList());
       for (Rep trackRep : playlists) {
         if (checkForMaster(trackRep.origMpfile)) {
           this.masters.add(trackRep);
           trackRep.setMaster(true); // Track.master is set by inspection
         }
         mapTracks(trackRep); // find relationships of playlist segments
       }
       this.segments = reps.stream().filter(r -> !r.isPlaylist).collect(Collectors.toList());
       if (this.segments.size() < 1)
         throw new MediaPackageException("No media segments");
     }
 
     // File references need to be fixed
     public boolean needsRewriting() {
       if (this.playlists.size() == 0) // not HLS
         return false;
       for (String s : fileMap.keySet()) { // paths are already corrected
         if (!s.equals(fileMap.get(s)))
           return true;
       }
       return false;
     }
 
     /**
      * Rewrite the playlist file from master on down, this has to be done in multiple steps because the act of putting a
      * file into a collection changes the path and new path is not known in advance. The two functions are passed in to
      * this function to manage the tracks in its storage
      *
      * @param mp
      *          to be rewrittem
      * @param replaceTrackFileInWS
      *          A function that creates a new track with the file using the metadata in the track, returning a new track
      *          in the media package.
      * @param removeFromWS
      *          A function that removes() the track from the media package in the workspace
      * @return old tracks that are removed from the media package
      * @throws MediaPackageException
      *           if bad mp
      */
     public List<Track> rewriteHLS(MediaPackage mp, BiFunction<File, Track, Track> replaceTrackFileInWS,
             Function<Track, Void> removeFromWS) throws MediaPackageException {
       /* rewrite variants first, * segments are unchanged */
       List<Rep> variants = playlists.stream().filter(i -> !masters.contains(i)).collect(Collectors.toList());
       List<File> newFiles = new ArrayList<File>();
       List<Track> oldTracks = new ArrayList<Track>();
       List<Track> newTracks = new ArrayList<Track>();
       Rep rep = segments.get(0); // use segment dir as temp space
 
 
       // Lambda to rewrite a track using the passed in functions, using closure
       Function<Rep, Boolean> rewriteTrack = (trackRep) -> {
         File srcFile = trackRep.origMpfile;
         // Use first segment's folder as temp space
         File destFile = new File(rep.origMpfile.getAbsoluteFile().getParent(),
                 FilenameUtils.getName(srcFile.getName()));
         try {
           hlsRewriteFileReference(srcFile, destFile, fileMap);
         } catch (IOException e) {
           logger.error("HLS Rewrite {} to {} failed", srcFile, destFile);
           return false;
         }
         newFiles.add(destFile);
         oldTracks.add(trackRep.track);
         Track copyTrack = (Track) trackRep.track.clone(); // get all the properties, id, etc
         mp.add(copyTrack); // add to mp and get new elementID
         Track newTrack = replaceTrackFileInWS.apply(destFile, copyTrack);
         if (newTrack == null) {
           logger.error("Cannot add HLS track tp MP: {}", trackRep.track);
           return false;
         }
         newTracks.add(newTrack);
 
         try { // Keep track of the new file's relative URI
           fileMap.put(trackRep.relPath, relativize(rep.origMpuri, newTrack.getURI()));
         } catch (URISyntaxException e) {
           logger.error("Cannot rewrite relativize track name: {}", trackRep.track);
           return false;
         }
         newTrack.setLogicalName(fileMap.get(trackRep.name)); // set logical name for publication
         return true;
       };
 
 
       try {
         // Rewrite the variants and masters tracks in order and throw exception if there are any failures
         if (!(variants.stream().map(t -> rewriteTrack.apply(t)).allMatch(Boolean::valueOf)
                 && masters.stream().map(t -> rewriteTrack.apply(t)).allMatch(Boolean::valueOf)))
           throw new IOException("Cannot rewrite track");
 
         // if segments are referenced by variant - set the logical name used
         for (Rep segment : segments) {
           if (fileMap.containsValue(segment.newfileName)) {
             segment.track.setLogicalName(segment.newfileName);
           }
         }
 
         oldTracks.forEach(t -> {
           mp.remove(t);
           removeFromWS.apply(t);
         }); // remove old tracks if successful
 
       } catch (IOException /* | URISyntaxException */ e) {
 
         logger.error("Cannot rewrite HLS tracks files:", e);
         newTracks.forEach(t -> {
           mp.remove(t);
           removeFromWS.apply(t);
         }); // remove new Tracks if any of them failed
         throw new MediaPackageException("Cannot rewrite HLS tracks files", e);
 
       } finally {
         newFiles.forEach(f -> f.delete()); // temp files not needed anymore
       }
       return oldTracks;
     }
 
     /**
      * Look for track by filename, assuming that all the variant playlists and segments are uniquely named. It is
      * possible that someone ingests a set of published playlists so the paths are nested. Then referenced names are
      * mapped to tracks.
      *
      * @param trackRep
      *          - playlist to examine
      * @throws IOException
      *           - bad files
      * @throws URISyntaxException
      */
     private void mapTracks(Rep trackRep) throws IOException, URISyntaxException {
       Set<String> paths = getVariants(trackRep.origMpfile); // Get all tracks it points to by path
       for (String path : paths) { // Check each file name
         String name = FilenameUtils.getName(path);
         if (repMap.containsKey(name)) {
           Rep rep = repMap.get(name);
           rep.newMpuri = trackRep.track.getURI().relativize(rep.origMpuri);
           rep.newfileName = relativize(trackRep.origMpuri, rep.origMpuri);
           fileMap.put(path, rep.newfileName);
           rep.relPath = path; // for reverse lookup
         } else {
           logger.warn("Adaptive Playlist referenced track not found in mediapackage");
         }
       }
     }
   }
 }