/*******************************************************************************
 * Copyright (c) 2005-2008 Polarion Software.
 * 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:
 *    Alexander Gurov - Initial API and implementation
 *    Julien HENRY - fix for the issue #350143 (svn:externals should not be treated as IRepositoryRoot entries)
 *    Claudio Weiler - special thanks for ideas and help related to implementation of human-readable/numeric ordering for branches and tags (see bug #390467)
 *******************************************************************************/

package org.eclipse.team.svn.core.operation.remote;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.team.svn.core.SVNMessages;
import org.eclipse.team.svn.core.SVNTeamPlugin;
import org.eclipse.team.svn.core.connector.ISVNConnector;
import org.eclipse.team.svn.core.connector.SVNEntryRevisionReference;
import org.eclipse.team.svn.core.connector.SVNProperty;
import org.eclipse.team.svn.core.connector.SVNProperty.BuiltIn;
import org.eclipse.team.svn.core.operation.AbstractActionOperation;
import org.eclipse.team.svn.core.operation.SVNProgressMonitor;
import org.eclipse.team.svn.core.operation.UnreportableException;
import org.eclipse.team.svn.core.resource.IRepositoryContainer;
import org.eclipse.team.svn.core.resource.IRepositoryLocation;
import org.eclipse.team.svn.core.resource.IRepositoryResource;
import org.eclipse.team.svn.core.resource.IRepositoryResource.Information;
import org.eclipse.team.svn.core.resource.IRepositoryRoot;
import org.eclipse.team.svn.core.svnstorage.SVNRemoteStorage;
import org.eclipse.team.svn.core.utility.SVNUtility;

/**
 * 
 * Load folder children. Used in asynchronous repository view refresh.
 * 
 * @author Alexander Gurov
 */
public class GetRemoteFolderChildrenOperation extends AbstractActionOperation {
	protected IRepositoryContainer parent;
	protected boolean handleExternals;
	protected IRepositoryResource []children;
	protected String []extNames;
	protected boolean caseInsensitive;

	public GetRemoteFolderChildrenOperation(IRepositoryContainer parent, boolean handleExternals) {
		this(parent, handleExternals, false);
	}

	public GetRemoteFolderChildrenOperation(IRepositoryContainer parent, boolean handleExternals, boolean caseInsensitive) {
		super("Operation_GetRemoteChildren", SVNMessages.class); //$NON-NLS-1$
		this.parent = parent;
		this.handleExternals = handleExternals;
		this.caseInsensitive = caseInsensitive;
	}

	public IRepositoryResource[] getChildren() {
		return this.children;
	}
	
	public String getExternalsName(int idx) {
		return this.extNames[idx];
	}

	protected void runImpl(IProgressMonitor monitor) throws Exception {
		IRepositoryResource []tmp = this.parent.getChildren();
		List<Object []> tmpSortableData = new ArrayList<Object []>(tmp.length);
		for (int i = 0; i < tmp.length; i++) {
			tmpSortableData.add(new Object[] {null, tmp[i]});
		}
		
		// handle svn:externals, if present:
		Information info = this.parent.getInfo();
		if (info != null && info.hasProperties && this.handleExternals) {
			IRepositoryLocation location = this.parent.getRepositoryLocation();
			ISVNConnector proxy = location.acquireSVNProxy();
			try {
				SVNProperty data = proxy.getProperty(SVNUtility.getEntryRevisionReference(this.parent), BuiltIn.EXTERNALS, null, new SVNProgressMonitor(this, monitor, null));
				if (data != null) {
					//Map externals;
					try {
						Map<String, SVNEntryRevisionReference> externals = SVNUtility.parseSVNExternalsProperty(data.value, this.parent);
						
						for (Iterator<Map.Entry<String, SVNEntryRevisionReference>> it = externals.entrySet().iterator(); it.hasNext();) {
							try {
								Map.Entry<String, SVNEntryRevisionReference> entry = it.next();
								String name = entry.getKey();
								SVNEntryRevisionReference ref = entry.getValue();
								IRepositoryResource repositoryResourtce = SVNRemoteStorage.instance().asRepositoryResource(location, ref, new SVNProgressMonitor(this, monitor, null));															
								if (repositoryResourtce != null) {
									repositoryResourtce.setSelectedRevision(ref.revision);
									repositoryResourtce.setPegRevision(ref.pegRevision);
									tmpSortableData.add(new Object[] {name, repositoryResourtce});
								}
							} catch (Exception e) {
								this.reportStatus(new Status(IStatus.WARNING, SVNTeamPlugin.NATURE_ID, IStatus.OK, this.getShortErrorMessage(e), e));
							}
						}
					}
					catch (UnreportableException ex) {
						this.reportStatus(new Status(IStatus.WARNING, SVNTeamPlugin.NATURE_ID, IStatus.OK, this.getShortErrorMessage(ex), ex));
					}
				}
			} finally {
				location.releaseSVNProxy(proxy);
			}
		}
		Object [][]sortableData = tmpSortableData.toArray(new Object[tmpSortableData.size()][]);

		Arrays.sort(sortableData, new Comparator<Object []>() {
			private NaturalComparator comparator = new NaturalComparator();
			
			public int compare(Object []firstArray, Object []secondArray) {
				IRepositoryResource first = (IRepositoryResource)firstArray[1], second = (IRepositoryResource)secondArray[1];
				String firstExtName = (String)firstArray[0], secondExtName = (String)secondArray[0];
				boolean firstContainer = first instanceof IRepositoryContainer;
				boolean secondContainer = second instanceof IRepositoryContainer;
				if (firstContainer && secondContainer) {
					boolean firstExternal = firstExtName != null;
					boolean secondExternal = secondExtName != null;
					//Externals should not be considered as IRepositoryRoot (see Bug 350143) and be sorted by name
					boolean firstRoot = !firstExternal && first instanceof IRepositoryRoot;
					boolean secondRoot = !secondExternal && second instanceof IRepositoryRoot;
					return firstRoot == secondRoot ? (firstRoot ? this.compareRoots(((IRepositoryRoot)first).getKind(), ((IRepositoryRoot)second).getKind()) : this.compareNames(first, firstExtName, second, secondExtName)) : (firstRoot ? -1 : 1);
				}
				return firstContainer == secondContainer ? this.compareNames(first, firstExtName, second, secondExtName) : (firstContainer ? -1 : 1);
			}
			
			private int compareNames(IRepositoryResource first, String firstExtName, IRepositoryResource second, String secondExtName) {
				String firstName = firstExtName != null ? firstExtName : first.getName();
				String secondName = secondExtName != null ? secondExtName : second.getName();
				return this.comparator.compare(firstName, secondName);
			}
			
			private int compareRoots(int firstKind, int secondKind) {
				return firstKind < secondKind ? -1 : 1;
			}
		});
		
		this.children = new IRepositoryResource[sortableData.length];
		this.extNames = new String[sortableData.length];
		for (int i = 0; i < sortableData.length; i++) {
			this.children[i] = (IRepositoryResource)sortableData[i][1];
			this.extNames[i] = (String)sortableData[i][0];
		}
	}
	
	private int compareStrings(String firstName, String secondName)
	{
		return this.caseInsensitive ? firstName.compareToIgnoreCase(secondName) : firstName.compareTo(secondName);
	}

	private class NaturalComparator implements Comparator<String> {
		public int compare(String o1, String o2) {
			// equal string, ignore all the rest
			if (GetRemoteFolderChildrenOperation.this.compareStrings(o1, o2) == 0) {
				return 0;
			}
			// empty string is lower
			if (o1.length() == 0) {
				return -1;
			}
			if (o2.length() == 0) {
				return 1;
			}
			
			// from now we consider a 'part' a sequence of digits or non-digits 

			// extract first part of o1
			String o1Part = "";
			int o1i = 0;
			boolean o1IsDigit = Character.isDigit(o1.charAt(o1i++));
			for (; o1i < o1.length(); o1i++) {
				if (Character.isDigit(o1.charAt(o1i)) != o1IsDigit) {
					break;
				}
			}
			o1Part = o1.substring(0, o1i);

			// extract first part of o2
			String o2Part = "";
			int o2i = 0;
			boolean o2IsDigit = Character.isDigit(o2.charAt(o2i++));
			for (; o2i < o2.length(); o2i++) {
				if (Character.isDigit(o2.charAt(o2i)) != o2IsDigit) {
					break;
				}
			}
			o2Part = o2.substring(0, o2i);

			// compare both parts
			int result = 0;
			if (o1IsDigit && o2IsDigit) {
				if (o1Part.charAt(0) == '0' && o2Part.charAt(0) != '0') {
					result = -1;
				}
				else if (o2Part.charAt(0) == '0' && o1Part.charAt(0) != '0') {
					result = 1;
				}
				else {
					// if both parts are number, then numeric test
					try {
						int n1 = Integer.parseInt(o1Part);
						int n2 = Integer.parseInt(o2Part);
						// if numbers are equal, make numeric test, else use string test
						result = n1 != n2 ? (n1 < n2 ? -1 : 1) : 0;
						if (result == 0 && o1Part.length() != o2Part.length()) {
							// leading zeros are relevant: more zeros first
							result = o1Part.length() < o2Part.length() ? 1 : -1;
						}
					} 
					catch (NumberFormatException nbe) {
						// should not enter here as we test for numeric parts
					}
				}
			}
			else {
				result = GetRemoteFolderChildrenOperation.this.compareStrings(o1Part, o2Part);
			}
			
			// if parts aren't equal return, otherwise continue test for the rest of the string
			return result != 0 ? result : this.compare(o1.substring(o1i), o2.substring(o2i));
		}
	}
}