/*******************************************************************************
 * Copyright (c) 2000, 2002 IBM Corporation and others.
 * All rights reserved.   This program and the accompanying materials
 * are made available under the terms of the Common Public License v0.5
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v05.html
 * 
 * Contributors:
 * IBM - Initial API and implementation
 ******************************************************************************/
package org.eclipse.team.internal.ccvs.core.client.listeners;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.team.internal.ccvs.core.CVSStatus;
import org.eclipse.team.internal.ccvs.core.ICVSFolder;
import org.eclipse.team.internal.ccvs.core.client.Update;

public class UpdateListener implements ICommandOutputListener {
	static final String SERVER_PREFIX = "cvs server: "; //$NON-NLS-1$
	static final String SERVER_ABORTED_PREFIX = "cvs [server aborted]: "; //$NON-NLS-1$

	IUpdateMessageListener updateMessageListener;
	boolean merging = false;

	public UpdateListener(IUpdateMessageListener updateMessageListener) {
		this.updateMessageListener = updateMessageListener;
	}
	
	public IStatus messageLine(String line, ICVSFolder commandRoot,
		IProgressMonitor monitor) {
		if (updateMessageListener == null) return OK;
		if(line.startsWith("Merging differences")) { //$NON-NLS-1$
			merging = true;
		} else if(line.indexOf(' ')==1) {
			// We have a message that indicates the type of update. The possible messages are
			// defined by the prefix constants MLP_*.
			String path = line.substring(2);
			char changeType = line.charAt(0);
			
			// calculate change type
			int type = 0;
			switch(changeType) {
				case 'A': type = Update.STATE_ADDED_LOCAL; break; // new file locally that was added but not comitted to server yet
				case '?': type = Update.STATE_UNKOWN; break; // new file locally but not added to server
				case 'U': type = Update.STATE_REMOTE_CHANGES; break;  // remote changes to an unmodified local file
				case 'R': type = Update.STATE_DELETED; break; // removed locally but still exists on the server
				case 'M': type = Update.STATE_MODIFIED; break; // modified locally
				case 'C': type = Update.STATE_CONFLICT; break;  // modified locally and on the server but cannot be auto-merged
				case 'D': type = Update.STATE_DELETED; break;  // deleted locally but still exists on server
				default: type = Update.STATE_NONE;
			}
				
			if (merging) {
				// If we are merging the modified prefix is used both to show merges and
				// local changes. We have to detect this case and use a more specific change
				// type.
				if (type == Update.STATE_MODIFIED)
					type = Update.STATE_MERGEABLE_CONFLICT;
				merging = false;
			}
			updateMessageListener.fileInformation(type, commandRoot, path);
		}
		return OK;
	}

	/**
	 * This handler is used by the RemoteResource hierarchy to retrieve E messages
	 * from the CVS server in order to determine the folders contained in a parent folder.
	 * 
	 * WARNING: This class parses the message output to determine the state of files in the
	 * repository. Unfortunately, these messages seem to be customizable on a server by server basis.
	 * 
	 * Here's a list of responses we expect in various situations:
	 * 
	 * Directory exists remotely:
	 *    cvs server: Updating folder1/folder2
	 * Directory doesn't exist remotely:
	 *    cvs server: skipping directory folder1/folder2
	 * New (or unknown) remote directory
	 *    cvs server: New Directory folder1/folder2
	 * File removed remotely
	 *    cvs server: folder1/file.ext is no longer in the repository
	 *    cvs server: warning: folder1/file.ext is not (any longer) pertinent
	 * Locally added file was added remotely as well
	 *    cvs server: conflict: folder/file.ext created independently by second party 
	 * File removed locally and modified remotely
	 *    cvs server: conflict: removed file.txt was modified by second party
	 * File modified locally but removed remotely
	 *    cvs server: conflict: file.txt is modified but no longer in the repository
	 * Ignored Messages
	 *    cvs server: cannot open directory ...
	 *    cvs server: nothing known about ...
	 * Tag error that really means there are no files in a directory
	 *    cvs [server aborted]: no such tag
	 */
	public IStatus errorLine(String line, ICVSFolder commandRoot,
		IProgressMonitor monitor) {
		
		if (line.startsWith(SERVER_PREFIX)) {
			// Strip the prefix from the line
			String message = line.substring(SERVER_PREFIX.length());
			if (message.startsWith("Updating")) { //$NON-NLS-1$
				if (updateMessageListener != null) {
					IPath path = new Path(message.substring(9));
					updateMessageListener.directoryInformation(commandRoot, path, false);
				}
				return OK;
			} else if (message.startsWith("skipping directory")) { //$NON-NLS-1$
				if (updateMessageListener != null) {
					IPath path = new Path(message.substring(18).trim());
					updateMessageListener.directoryDoesNotExist(commandRoot, path);
				}
				return OK;
			} else if (message.startsWith("New directory")) { //$NON-NLS-1$
				if (updateMessageListener != null) {
					IPath path = new Path(message.substring(15, message.indexOf('\'', 15)));
					updateMessageListener.directoryInformation(commandRoot, path, true);
				}
				return OK;
			} else if (message.endsWith("is no longer in the repository")) { //$NON-NLS-1$
				if (updateMessageListener != null) {
					String filename = message.substring(0, message.length() - 31);
					updateMessageListener.fileDoesNotExist(commandRoot, filename);
				}
				return OK;
			} else if (message.startsWith("conflict:")) { //$NON-NLS-1$
				/*
				 * We can get the following conflict warnings
				 *    cvs server: conflict: folder/file.ext created independently by second party 
				 *    cvs server: conflict: removed file.txt was modified by second party
				 *    cvs server: conflict: file.txt is modified but no longer in the repository
				 * If we get the above line, we have conflicting additions or deletions and we can expect a server error.
				 * We still get "C foler/file.ext" so we don't need to do anything else (except in the remotely deleted case)
				 */
				if (updateMessageListener != null) {
					if (message.endsWith("is modified but no longer in the repository")) { //$NON-NLS-1$
						// The "C foler/file.ext" will come after this so if whould be ignored!
						String filename = message.substring(10, message.length() - 44);
						updateMessageListener.fileDoesNotExist(commandRoot, filename);
					}
				}
				return new CVSStatus(CVSStatus.WARNING, CVSStatus.CONFLICT, line);
			} else if (message.startsWith("warning:")) { //$NON-NLS-1$
				/*
				 * We can get the following conflict warnings
				 *    cvs server: warning: folder1/file.ext is not (any longer) pertinent
				 * If we get the above line, we have local changes to a remotely deleted file.
				 */
				if (updateMessageListener != null) {
					if (message.endsWith("is not (any longer) pertinent")) { //$NON-NLS-1$
						String filename = message.substring(9, message.length() - 30);
						updateMessageListener.fileDoesNotExist(commandRoot, filename);
					}
				}
				return new CVSStatus(CVSStatus.WARNING, CVSStatus.CONFLICT, line);
			} else if (message.startsWith("conflicts")) { //$NON-NLS-1$
				// This line is info only. The server doesn't report an error.
				return new CVSStatus(IStatus.INFO, CVSStatus.CONFLICT, line);
			} else if (!message.startsWith("cannot open directory") //$NON-NLS-1$
					&& !message.startsWith("nothing known about")) { //$NON-NLS-1$
				return new CVSStatus(CVSStatus.ERROR, CVSStatus.ERROR_LINE, line);
			}
		} else if (line.startsWith(SERVER_ABORTED_PREFIX)) {
			// Strip the prefix from the line
			String message = line.substring(SERVER_ABORTED_PREFIX.length());
			if (message.startsWith("no such tag")) { //$NON-NLS-1$
				// This is reported from CVS when a tag is used on the update there are no files in the directory
				// To get the folders, the update request should be re-issued for HEAD
				return new CVSStatus(CVSStatus.WARNING, CVSStatus.NO_SUCH_TAG, line);
			} else {
				return new CVSStatus(CVSStatus.ERROR, CVSStatus.ERROR_LINE, line);
			}
		}
		return new CVSStatus(CVSStatus.ERROR, CVSStatus.ERROR_LINE, line);
	}
}