package net.sf.jpkgmk.pkgmap;
   
   import java.io.File;
   import java.io.IOException;
   import java.io.Writer;
   import java.util.ArrayList;
   import java.util.Collections;
   import java.util.Comparator;
   import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.Set;
  
  import net.sf.jpkgmk.AbstractFileCreatorAdapter;
  import net.sf.jpkgmk.DefaultFileHandler;
  import net.sf.jpkgmk.FileHandler;
  import net.sf.jpkgmk.PackageException;
  import net.sf.jpkgmk.util.ObjectUtils;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /**
   * pkgmap is an ASCII file that provides a complete listing of the package contents. 
   * It is automatically generated by pkgmk(1) using the information in the prototype(4) file.
   * 
   * Representation of a package map file (called "pkgmap" on the filesystem).
   * The pkgmap file is a packing list, where each item in the package is defined and its size and 
   * checksum are stored. The size and checksum help in determining that the package has not 
   * been tampered with. The various items in the pkgmap are recognized by their ftype entry as shown here.
   * 
   * See 
   * <a href="http://docs.sun.com/app/docs/doc/805-6338">sun docs</a>
   * <a href="http://www.cs.biu.ac.il/cgi-bin/man?pkgmap+4">http://www.cs.biu.ac.il/cgi-bin/man?pkgmap+4</a> and
   * <a href="http://www.sun.com/bigadmin/features/techtips/package_components.jsp">http://www.sun.com/bigadmin/features/techtips/package_components.jsp</a>
   * <a href="http://www.softpanorama.org/Solaris/Packages/index.shtml">http://www.softpanorama.org/Solaris/Packages/index.shtml</a>.
   * 
   * @author gommma (gommma AT users.sourceforge.net)
   * @author Last changed by: $Author: gommma $
   * @version $Revision: 2 $ $Date: 2008-08-20 21:14:19 +0200 (Mi, 20 Aug 2008) $
   * @since 1.0
   */
  public class PkgMap extends AbstractFileCreatorAdapter
  {
      /**
       * Integer constant for the value {@value}
       */
      private static final Integer ONE = Integer.valueOf(1);
  
      /**
  	 * The name of the file on the filesystem
  	 */
  	public static final String PKGMAP="pkgmap";
  
  	
  	private Log log = LogFactory.getLog(PkgMap.class);
  	/**
  	 * Set holding all entries of the package map
  	 */
  	private List<PkgMapEntry> pkgMapEntryList = new ArrayList<PkgMapEntry>();
  	private PkgMapEntryHeader header;
  	
  	/**
  	 */
  	public PkgMap() {
  		super();
  	}
  
  	
  
  	@Override
  	public FileHandler getFileHandler(File targetDir) {
  		DefaultFileHandler fileCreator = new DefaultFileHandler(targetDir, PKGMAP);
  		return fileCreator;
  	}
  
  
  	public void writeContent(Writer writer) throws IOException 
  	{
  		// 1. create the pkgmap header
  		if(this.header == null) {
  			throw new IllegalStateException("Before creating the pkgmap, the header must be set via setHeader().");
  		}
  		header.write(writer);
  		
  		// 2. sort the entries
  		sort(this.pkgMapEntryList);
  		
  		// 3. create the lines
  		for(Iterator<PkgMapEntry> iter=this.pkgMapEntryList.iterator(); iter.hasNext(); ) {
  			PkgMapEntry entry = (PkgMapEntry)iter.next();
  			entry.write(writer);
  		}
  		writer.flush();
  	}
  
  	/**
  	 * Sorts the given list of pkgmap entries.
 	 * <p>
 	 * As defined in the sun docs:
 	 * &quot;The package objects in pkgmap are listed in alphabetical order by class and by path name to
 	 * reduce the time it takes to install the package.&quot;
 	 * </p>
 	 * @param pkgMapEntryList2
 	 */
 	void sort(List<PkgMapEntry> pkgMapEntryList2) {
 
 		log.debug("<entering> sort(List<PkgMapEntry>)");
 		
 		List<EntryCommentAssociation> entryCommandAssocList = createEntryCommandAssoc(pkgMapEntryList2);
 
 		// Remove comments
 		List<PkgMapEntry> entryListWithoutComments = filterComments(pkgMapEntryList2);
 		// Sort the entries now
 		Collections.sort(entryListWithoutComments, new PkgMapEntrySorter());
 		// At the end, add the comments at the locations where they belong
 		List<PkgMapEntry> fullResultList = addCommentsIfNeeded(entryListWithoutComments, entryCommandAssocList);
 		// assign the result list to this object as new package map
 		this.pkgMapEntryList = fullResultList;
 	}
 
 	private List<PkgMapEntry> addCommentsIfNeeded(List<PkgMapEntry> entryListWithoutComments,
 			List<EntryCommentAssociation> entryCommandAssocList) {
 		
 		List<PkgMapEntry> resultList = new ArrayList<PkgMapEntry>();
 		for(PkgMapEntry currentEntry : entryListWithoutComments) {
 			// Search the entry in the entryCommentAssoc list
 			for(EntryCommentAssociation entryCommentAssoc : entryCommandAssocList)
 			{
 				if(entryCommentAssoc.getEntry().equals(currentEntry)) {
 					// Add the comments to the entry list
 					resultList.addAll(entryCommentAssoc.getCommentList());
 					break;
 				}
 			}
 			// Finally add the entry itself
 			resultList.add(currentEntry);
 		}
 		return resultList;
 	}
 
 
 	private List<PkgMapEntry> filterComments(List<PkgMapEntry> pkgMapEntryList2) {
 		List<PkgMapEntry> resultList = new ArrayList<PkgMapEntry>();
 		for (PkgMapEntry pkgMapEntry : pkgMapEntryList2) {
 			if( !(pkgMapEntry instanceof PkgMapEntryComment)) {
 				resultList.add(pkgMapEntry);
 			}
 		}
 		return resultList;
 	}
 
 
 	private List<EntryCommentAssociation> createEntryCommandAssoc(List<PkgMapEntry> pkgMapEntryList2) {
 		List<EntryCommentAssociation> assocList = new ArrayList<EntryCommentAssociation>();
 		List<PkgMapEntryComment> commentList = new ArrayList<PkgMapEntryComment>();
 
 		for(PkgMapEntry entry : pkgMapEntryList2) {
 			if(entry instanceof PkgMapEntryComment) {
 				// Collect the comment
 				commentList.add((PkgMapEntryComment)entry);
 			}
 			else {
 				AbstractPkgMapEntry mapEntry = (AbstractPkgMapEntry)entry;
 				if(!commentList.isEmpty()) {
 					// Create association of previous comments with this entry
 					EntryCommentAssociation entryCommentAssoc = new EntryCommentAssociation(mapEntry, commentList);
 					assocList.add(entryCommentAssoc);
 					// create new list for comment entries - the old one has finished with the curent entry
 					commentList = new ArrayList<PkgMapEntryComment>();
 				}
 				else {
 					log.debug("Comment list is empty. No need to create a comment association for current entry.");
 				}
 			}
 		}
 		return assocList;
 	}
 
 
 
 	/**
 	 * @return Unmodifiable list of the pkgmap entries
 	 */
 	public List<PkgMapEntry> getPkgMapEntries()
 	{
 		return Collections.unmodifiableList(this.pkgMapEntryList);
 	}
 	
 	/**
 	 * Adds all the given entries to this pkgmap object.
 	 * @param pkgMapEntryList
 	 */
 	public void addAll(List<PkgMapEntry> pkgMapEntryList) {
 		for (Iterator<PkgMapEntry> iterator = pkgMapEntryList.iterator(); iterator.hasNext();) {
 			PkgMapEntry pkgMapEntry = iterator.next();
 			this.add(pkgMapEntry);
 		}
 	}
 
 	/**
 	 * Adds a prototype entry. Does <b>not</b> create the physical file yet
 	 * @param entry
 	 * @return Returns <code>true</code> if the entry was added successfully.
 	 */
 	public void add(PkgMapEntry entry) {
 		log.debug("Adding entry: " + entry);
 		
 		if(PkgMapEntryHeader.class.isAssignableFrom(entry.getClass())) {
 			this.setHeader((PkgMapEntryHeader)entry);
 		}
 		else {
 			if(pkgMapEntryList.contains(entry)) {
 				// Get the entry that already exists in the map
 				PkgMapEntry existingEntry = findEntryThatEquals(entry);
 				throw new PackageException("Entry that equals the given one '" + entry + "' already exists in the current map. Equal entry in list: '" + existingEntry + "'.");
 			}
 			boolean success = pkgMapEntryList.add(entry);
 			if(!success) {
 				throw new PackageException("Failed to add the entry '" + entry + "' to the map.");
 	//			log.warn("Failed to add the entry '" + entry + "' to the collection '" + pkgMapEntryList + "'.");
 			}
 		}
 	}
 
 	/**
 	 * Sets the only header for this pkgmap. If it was already set before, an exception is thrown.
 	 * @param header
 	 */
 	public void setHeader(PkgMapEntryHeader header) {
 		if(this.header != null) {
 			throw new IllegalStateException("The header is already set. Cannot overwrite");
 		}
 		if(header == null) {
 			log.info("Resetting pkgmap header to null");
 		}
 		this.header = header;
 	}
 
 	public PkgMapEntryHeader getHeader() {
 		return this.header;
 	}
 	
 	/**
 	 * @return Returns the number of entries that are currently in this map
 	 */
 	public int getSize() {
 		return this.pkgMapEntryList.size();
 	}
 
 	/**
 	 * Searches for an entry in the {@link #pkgMapEntryList} which equals the given entry (current.equals(entry)==true).
 	 * @param entry The entry to be searched
 	 * @return The result entry or null if no equal entry was found
 	 */
 	private PkgMapEntry findEntryThatEquals(PkgMapEntry entry) 
 	{
 		for(Iterator<PkgMapEntry> iter=this.pkgMapEntryList.iterator(); iter.hasNext(); ) {
 			PkgMapEntry currentEntry = (PkgMapEntry)iter.next();
 			if(currentEntry.equals(entry)) {
 				return currentEntry;
 			}
 		}
 		return null;
 	}
 
 	/**
 	 * @return The number of different parts that exist in the current pkgmap. If the part of an entry
 	 * is <code>null</code>, the value 1 is assumed by default as defined in the sun specs.
 	 */
 	public Integer getNumberOfParts() {
 		Set<Integer> foundParts = new HashSet<Integer>();
 		for(Iterator<PkgMapEntry> iter=this.pkgMapEntryList.iterator(); iter.hasNext(); ) {
 			PkgMapEntry currentEntry = (PkgMapEntry)iter.next();
 			if(PkgMapEntryFile.class.isAssignableFrom(currentEntry.getClass())) {
 				PkgMapEntryFile currentEntryFile = (PkgMapEntryFile)currentEntry;
 				Integer part = currentEntryFile.getPart();
 				if(part==null) {
 					// By default, if no part is specified, the pkgadd assumes that "1" is meant.
 					part = ONE;
 				}
 				foundParts.add(part);
 			}
 		}
 		return foundParts.size();
 	}
 
 	@Override
 	public int hashCode() {
 		final int prime = 31;
 		int result = 1;
 		result = prime * result + ((header == null) ? 0 : header.hashCode());
 		result = prime * result
 				+ ((pkgMapEntryList == null) ? 0 : pkgMapEntryList.hashCode());
 		return result;
 	}
 
 
 
 	@Override
 	public boolean equals(Object obj) {
 		return this.equals(obj, false);
 	}
 
 	/**
 	 * @param obj
 	 * @param ignoreLastModified
 	 * @return
 	 */
 	public boolean equals(Object obj, boolean ignoreLastModified) {
 		if (this == obj)
 			return true;
 		if (obj == null)
 			return false;
 		if (getClass() != obj.getClass())
 			return false;
 		final PkgMap other = (PkgMap) obj;
 		
 		if(!ObjectUtils.areObjectsEqual(this.header, other.header))
 			return false;
 
 		if (pkgMapEntryList == null) {
 			if (other.pkgMapEntryList != null)
 				return false;
 		} else if (!listsEqual(pkgMapEntryList, other.pkgMapEntryList, ignoreLastModified))
 			return false;
 		return true;
 	}
 
 	
 
 	private boolean listsEqual(List<PkgMapEntry> list1,
 			List<PkgMapEntry> list2, boolean ignoreLastModified) {
 		if(!ignoreLastModified) {
 			return list1.equals(list2);
 		}
 		else {
 			
 			ListIterator<PkgMapEntry> e1 = list1.listIterator();
 			ListIterator<PkgMapEntry> e2 = list2.listIterator();
 			while(e1.hasNext() && e2.hasNext()) {
 				PkgMapEntry o1 = e1.next();
 				PkgMapEntry o2 = e2.next();
 			    if (!(o1==null ? o2==null : o1.equals(o2, ignoreLastModified)))
 			    	return false;
 			}
 			return !(e1.hasNext() || e2.hasNext());
 		}
 	}
 
 
 
 	@Override
 	public String toString()
 	{
 		StringBuffer sb = new StringBuffer();
 		sb.append(getClass().getName()).append("[");
 		sb.append(super.toString());
 		sb.append("[");
 		sb.append("entries=").append(this.pkgMapEntryList);
 		sb.append("]");
 		sb.append("]");
 		return sb.toString();
 	}
 
 	
 	
 	
 	/**
 	 * Sorter for PkgMap entries
 	 */
 	private static class PkgMapEntrySorter implements Comparator<PkgMapEntry>
 	{
 
 		public int compare(PkgMapEntry o1, PkgMapEntry o2) {
 			if(o1 instanceof PkgMapEntryHeader) {
 				return -1;
 			}
 			else if(o2 instanceof PkgMapEntryHeader) {
 				return 1;
 			}
 			else if(o1 instanceof AbstractPkgMapEntry && o2 instanceof AbstractPkgMapEntry) {
 				AbstractPkgMapEntry o1Abstract = (AbstractPkgMapEntry)o1;
 				AbstractPkgMapEntry o2Abstract = (AbstractPkgMapEntry)o2;
 				return o1Abstract.compareTo(o2Abstract);
 			}
 			else {
 				throw new UnsupportedOperationException("Unknown pkgmap entry type: " + o1 + " and " + o2);
 			}
 		}
 		
 	}
 	
 	/**
 	 * Links a pkgmap entry with one or more comments
 	 */
 	private static class EntryCommentAssociation
 	{
 		private PkgMapEntry entry;
 		private List<PkgMapEntryComment> commentList;
 		
 		public EntryCommentAssociation(PkgMapEntry entry, List<PkgMapEntryComment> commentList)
 		{
 			this.entry = entry;
 			this.commentList = commentList;
 		}
 
 		public PkgMapEntry getEntry() {
 			return entry;
 		}
 
 		public List<PkgMapEntryComment> getCommentList() {
 			return commentList;
 		}
 		
 	}
 
 }