/*******************************************************************************
 * Copyright (c) 2001, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.j2ee.commonarchivecore.internal.strategy;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.jst.j2ee.commonarchivecore.internal.util.ArchiveUtil;
import org.eclipse.jst.j2ee.commonarchivecore.looseconfig.internal.LooseApplication;
import org.eclipse.jst.j2ee.commonarchivecore.looseconfig.internal.LooseArchive;
import org.eclipse.jst.j2ee.commonarchivecore.looseconfig.internal.LooseWARFile;
import org.eclipse.jst.j2ee.commonarchivecore.looseconfig.internal.LooseconfigPackage;


/**
 * Implementer that knows how to read files from the local file system and treat them as file
 * entries in an archive
 * 
 * @see DirectoryArchiveLoadStrategy
 */
public abstract class DirectoryLoadStrategyImpl extends LoadStrategyImpl implements DirectoryArchiveLoadStrategy {
	/**
	 * The root uri from which all relative files entries are loaded; must point to a valid local
	 * directory
	 */
	static boolean IS_AIX = "AIX".equals(System.getProperty("os.name")); //$NON-NLS-1$ //$NON-NLS-2$
	protected String directoryUri;
	/**
	 * Used internally; the directory uri with the system dependent file separator replaced by a
	 * forward slash
	 */
	protected String directoryUriAsZipString;
	protected static char SEPARATOR_CHAR = java.io.File.separatorChar;

	public DirectoryLoadStrategyImpl(String aDirectoryUri) {
		super();
		setDirectoryUri(aDirectoryUri);
		String normalized = null;
		try {
			normalized = new File(aDirectoryUri).getCanonicalPath();
		} catch (IOException iox) {
			normalized = aDirectoryUri;
		}
		setDirectoryUriAsZipString(normalized.replace(SEPARATOR_CHAR, '/'));

	}

	protected abstract void addDirectory(java.io.File aFile, List aList);

	protected void addFile(java.io.File aFile, List aList) {

		String uri = getURIFrom(aFile);
		if (collectedLooseArchiveFiles.containsKey(uri))
			return;

		org.eclipse.jst.j2ee.commonarchivecore.internal.File cFile = createFile(uri);
		cFile.setSize(aFile.length());
		cFile.setLastModified(aFile.lastModified());
		aList.add(cFile);
	}

	protected void addFiles(java.io.File aDirectory, List aList) {

		String[] fileNames = aDirectory.list();
		if (fileNames == null)
			return;
		for (int i = 0; i < fileNames.length; i++) {
			String fileName = ArchiveUtil.concatUri(aDirectory.getPath(), fileNames[i], SEPARATOR_CHAR);
			if (fileNames[i] == null || (IS_AIX && ".backup".equals(fileNames[i]))) //$NON-NLS-1$
				continue;
			java.io.File aFile = new java.io.File(fileName);
			if (!aFile.exists())
				continue;
			//This could occur on some windows machines, eg C:\pagefile.sys
			//throw new RuntimeException("Error scanning directory structure");
			if (aFile.isDirectory() && !isArchive(getURIFrom(aFile))) {
				addDirectory(aFile, aList);
			} else {
				addFile(aFile, aList);
			}
		}
	}

	/**
	 * @see com.ibm.etools.archive.impl.LoadStrategyImpl
	 */
	@Override
	protected boolean primContains(java.lang.String uri) {
		return new java.io.File(getFileNameFrom(uri)).exists();
	}

	/**
	 * @see com.ibm.etools.archive.LoadStrategy
	 */
	@Override
	public java.lang.String getAbsolutePath() throws java.io.FileNotFoundException {
		return new java.io.File(getDirectoryUri()).getAbsolutePath();
	}

	protected abstract java.io.File getDirectoryForList();

	public java.lang.String getDirectoryUri() {
		return directoryUri;
	}

	public java.lang.String getDirectoryUriAsZipString() {
		return directoryUriAsZipString;
	}

	/**
	 * Returns an OS filename from a relative uri
	 */
	// TODO Fix the type casing in v6.0
	protected String getFileNameFrom(String uri) {
		LooseArchive aLooseArchive = getLooseArchive();
		if (aLooseArchive != null) {
			String result = null;
			switch (aLooseArchive.eClass().getClassifierID()) {
				case LooseconfigPackage.LOOSE_APPLICATION :
					result = getURIFromLooseArchivesIfAvailable(((LooseApplication) aLooseArchive).getLooseArchives(), uri);
					break;
				case LooseconfigPackage.LOOSE_WAR_FILE :
					result = getURIFromLooseArchivesIfAvailable(((LooseWARFile) aLooseArchive).getLooseLibs(), uri);

					break;
			}
			if (result != null)
				return result;
		}
		String name = uri;
		if (SEPARATOR_CHAR != '/')
			name = name.replace('/', SEPARATOR_CHAR);
		return getDirectoryUri() + SEPARATOR_CHAR + name;
	}

	private String getURIFromLooseArchivesIfAvailable(List looseArchives, String uri) {

		for (Iterator iter = looseArchives.iterator(); iter.hasNext();) {
			LooseArchive looseArchiveElement = (LooseArchive) iter.next();
			if (uri.equals(looseArchiveElement.getUri()))
				return looseArchiveElement.getBinariesPath();
		}
		return null;
	}

	/**
	 * @see com.ibm.etools.archive.impl.LoadStrategyImpl
	 */
	@Override
	public java.util.List getFiles() {
		List list = new ArrayList();
		java.io.File directory = getDirectoryForList();
		addFiles(directory, list);
		return list;
	}
	
	@Override
	public java.util.List getFiles(String subfolderPath) {
		List list = new ArrayList();
		java.io.File containerDirectory = getDirectoryForList();
		java.io.File subfolder = new java.io.File(containerDirectory, subfolderPath);
		addFiles(subfolder, list);
		return list;
	}

	/**
	 * @see com.ibm.etools.archive.impl.LoadStrategyImpl
	 */
	@Override
	public java.io.InputStream getInputStream(java.lang.String uri) throws IOException, FileNotFoundException {
		return new FileInputStream(getFileNameFrom(uri));
	}

	/**
	 * Returns a relative uri from the java.io.File, to be used for a file entry; the separator will
	 * be the zip standard (forward slash ("/")).
	 */

	protected String getURIFrom(File aFile) {
		String name = ""; //$NON-NLS-1$
		String relative = null;
		String root = getDirectoryUriAsZipString();
		try {
			name = aFile.getCanonicalPath();
			relative = makeRelative(name, root);
		} catch (IOException iox) {
			name = null;
		}
		if (relative == null) {
			name = aFile.getAbsolutePath();
			relative = makeRelative(name, root);
		}
		if (relative == null) {
			name = aFile.getPath();
			root = replaceSeparators(getDirectoryUri());
			relative = makeRelative(name, root);
		}
		return relative;
	}

	private String replaceSeparators(String path) {
		if (File.separatorChar != '/')
			return path.replace(File.separatorChar, '/');
		return path;
	}

	private String makeRelative(String fileName, String root)
	{
	    if ( (fileName == null) || (root == null) )
	        return null;

	    int offset = root.length();

	    while ( (offset > 0) && root.charAt(offset - 1) == '/' )
	        offset--;

	    if ( offset < root.length() ) {
	        offset++;

	        if ( offset < root.length() )
	            root = root.substring(0, offset);
	    } else {
	        root += '/';
	    }

	    String name = replaceSeparators(fileName);

	    if ( name.startsWith(root) )
	        name = name.substring( root.length() );
	    else
	        name = null;

	    return name;
	}

	/**
	 * @see com.ibm.etools.archive.LoadStrategy
	 */
	@Override
	public boolean isDirectory() {
		return true;
	}

	/**
	 * @see com.ibm.etools.archive.LoadStrategy
	 */
	@Override
	public boolean isUsing(java.io.File aSystemFile) {
		java.io.File dir = new java.io.File(getDirectoryUri());
		return dir.equals(aSystemFile);
	}

	public void setDirectoryUri(java.lang.String newDirectoryUri) {
		directoryUri = newDirectoryUri;
	}

	public void setDirectoryUriAsZipString(java.lang.String newDirectoryUriAsZipString) {
		directoryUriAsZipString = newDirectoryUriAsZipString;
	}
}