/*******************************************************************************
 * Copyright (c) 2000, 2011 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Red Hat Incorporated - is/setExecutable() code
 *******************************************************************************/
package org.eclipse.team.internal.ccvs.core.resources;

import java.io.File;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.eclipse.core.resources.*;
import org.eclipse.core.runtime.*;
import org.eclipse.osgi.util.NLS;
import org.eclipse.team.core.RepositoryProvider;
import org.eclipse.team.core.TeamException;
import org.eclipse.team.internal.ccvs.core.*;
import org.eclipse.team.internal.ccvs.core.client.Session;
import org.eclipse.team.internal.ccvs.core.syncinfo.*;

/**
 * Represents handles to CVS resource on the local file system. Synchronization
 * information is taken from the CVS subdirectories. 
 */
public class EclipseFile extends EclipseResource implements ICVSFile {

	private static final String TEMP_FILE_EXTENSION = ".tmp";//$NON-NLS-1$
	private static final IPath PROJECT_META_DATA_PATH = new Path(".project");//$NON-NLS-1$
	
	/**
	 * Create a handle based on the given local resource.
	 */
	protected EclipseFile(IFile file) {
		super(file);
	}

	@Override
	public void delete() throws CVSException {
		try {
			((IFile)resource).delete(false /*force*/, true /*keepHistory*/, null);
		} catch(CoreException e) {
			throw CVSException.wrapException(resource, NLS.bind(CVSMessages.EclipseFile_Problem_deleting_resource, new String[] { resource.getFullPath().toString(), e.getStatus().getMessage() }), e); // 
		}
	}
	
	public long getSize() {
		return getIOFile().length();	
	}

	public InputStream getContents() throws CVSException {
		try {
			return getIFile().getContents();
		} catch (CoreException e) {
			throw CVSException.wrapException(resource, NLS.bind(CVSMessages.EclipseFile_Problem_accessing_resource, new String[] { resource.getFullPath().toString(), e.getStatus().getMessage() }), e); // 
		}
	}
	
	@Override
	public Date getTimeStamp() {
		long timestamp = getIFile().getLocalTimeStamp();
		if( timestamp == IResource.NULL_STAMP) {
			// If there is no file, return the same timestamp as ioFile.lastModified() would
			return new Date(0L);
		}			
		return new Date((timestamp/1000)*1000);
	}
 
	@Override
	public void setTimeStamp(Date date) throws CVSException {
		long time;
		if (date == null) {
			time = System.currentTimeMillis();
		} else {
			time = date.getTime();
		}
		EclipseSynchronizer.getInstance().setTimeStamp(this, time);
	}

	@Override
	public boolean isFolder() {
		return false;
	}
	
	/*
	 * @see ICVSFile#isModified()
	 */
	public boolean isModified(IProgressMonitor monitor) throws CVSException {
		
		// ignore the monitor, there is no valuable progress to be shown when
		// calculating the dirty state for files. It is relatively fast.
		
		if (!exists()) {
			return getSyncBytes() != null;
		}
		int state = EclipseSynchronizer.getInstance().getModificationState(getIFile());

		if (state != UNKNOWN) {
			boolean dirty = state != CLEAN;
			// Check to make sure that cached state is the real state.
			// They can be different if deltas happen in the wrong order.
			if (dirty == isDirty()) {
				return dirty;
			}
		}
		
		// nothing cached, need to manually check (and record)
		byte[] syncBytes = getSyncBytes();
		if (syncBytes == null && isIgnored()) return false;
		// unmanaged files are reported as modified
		return EclipseSynchronizer.getInstance().setModified(this, UNKNOWN);
	}
	
	@Override
	public void accept(ICVSResourceVisitor visitor) throws CVSException {
		visitor.visitFile(this);
	}

	@Override
	public void accept(ICVSResourceVisitor visitor, boolean recurse) throws CVSException {
		visitor.visitFile(this);
	}
	
	/*
	 * This is to be used by the Copy handler. The filename of the form .#filename
	 */
	public void copyTo(String filename) throws CVSException {
		try {
			IPath targetPath = new Path(null, filename);
			IFile targetFile = getIFile().getParent().getFile(targetPath);
			if (targetFile.exists()) {
				// There is a file in the target location. 
				// Delete it and keep the history just in case
				targetFile.delete(false /* force */, true /* keep history */, null);
			}
			getIFile().copy(targetPath, true /*force*/, null);
		} catch(CoreException e) {
			throw new CVSException(e.getStatus());
		}
	}

	@Override
	public String getRemoteLocation(ICVSFolder stopSearching) throws CVSException {
		return getParent().getRemoteLocation(stopSearching) + SEPARATOR + getName();
	}
		
	@Override
	public void setContents(InputStream stream, int responseType, boolean keepLocalHistory, IProgressMonitor monitor) throws CVSException {
		try {
			IFile file = getIFile();
			if (PROJECT_META_DATA_PATH.equals(file.getFullPath().removeFirstSegments(1))) {
				responseType = UPDATED;
			}
			switch (responseType) {
				case UPDATED:
					if (resource.exists()) {
						file.setContents(stream, false /*force*/, true /*keep history*/, monitor);
						break;
					}
				case CREATED: // creating a new file so it should not exist locally
					file.create(stream, false /*force*/, monitor);
					break;
				case MERGED: // merging contents into a file that exists locally
					// Ensure we don't leave the file in a partially written state
					IFile tempFile = file.getParent().getFile(new Path(null, file.getName() + TEMP_FILE_EXTENSION));
					monitor.beginTask(null, 100);
					if (tempFile.exists()) 
						tempFile.delete(true /* force */, Policy.subMonitorFor(monitor, 25));
					tempFile.create(stream, true /*force*/, Policy.subMonitorFor(monitor, 25));
					file.delete(false /* force */, true /* keep history */, Policy.subMonitorFor(monitor, 25));
					tempFile.move(new Path(null, file.getName()), false /*force*/, true /*history*/, Policy.subMonitorFor(monitor, 25));
					monitor.done();
					break;
				case UPDATE_EXISTING: // creating a new file so it should exist locally
					file.setContents(stream, false /*force*/, true /*keep history*/, monitor);
					break;
			}
		} catch(CoreException e) {
			String message = null;
			if (e.getStatus().getCode() == IResourceStatus.FAILED_READ_LOCAL) {
				// This error indicates that Core couldn't read from the server stream
				// The real reason will be in the message of the wrapped exception
				Throwable t = e.getStatus().getException();
				if (t != null) message = t.getMessage();
			}
			if (message == null) message = e.getMessage();
			throw CVSException.wrapException(resource, NLS.bind(CVSMessages.EclipseFile_Problem_writing_resource, new String[] { resource.getFullPath().toString(), message }), e); 
		}
	}
			
	@Override
	public void setReadOnly(boolean readOnly) throws CVSException {
		ResourceAttributes attributes = resource.getResourceAttributes();
		if (attributes != null) {
			attributes.setReadOnly(readOnly);
			try {
				resource.setResourceAttributes(attributes);
			} catch (CoreException e) {
				throw CVSException.wrapException(e);
			}
		}
	}

	@Override
	public boolean isReadOnly() throws CVSException {
		return getIFile().isReadOnly();
	}
	
	@Override
	public void setExecutable(boolean executable) throws CVSException {
		ResourceAttributes attributes = resource.getResourceAttributes();
		if (attributes != null) {
			attributes.setExecutable(executable);
			try {
				resource.setResourceAttributes(attributes);
			} catch (CoreException e) {
				throw CVSException.wrapException(e);
			}
		}
	}

	@Override
	public boolean isExecutable() throws CVSException {
		ResourceAttributes attributes = resource.getResourceAttributes();
		if (attributes != null) {
			return attributes.isExecutable();
		} else {
			return false;
		}
	}
	
	/*
	 * Typecasting helper
	 */
	public IFile getIFile() {
		return (IFile)resource;
	}	
	
	/*
	 * To allow accessing size and timestamp for the underlying java.io.File
	 */
	private File getIOFile() {
		IPath location = resource.getLocation();
		if(location!=null) {
			return location.toFile();
		}
		return null;
	}
	@Override
	public ILogEntry[] getLogEntries(IProgressMonitor monitor)	throws TeamException {
		
		// try fetching log entries only when the file's project is accessible
		// see bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=190434
		if (getIResource() == null
				|| !getIResource().getProject().isAccessible())
			return new ILogEntry[0];
		
		byte[] syncBytes = getSyncBytes();
		if(syncBytes != null && !ResourceSyncInfo.isAddition(syncBytes)) {
			ICVSRemoteResource remoteFile = CVSWorkspaceRoot.getRemoteResourceFor(resource);
			if (remoteFile != null)
				return ((ICVSRemoteFile)remoteFile).getLogEntries(monitor);
		}
		return new ILogEntry[0];
	}
	/**
	 * @see org.eclipse.team.internal.ccvs.core.ICVSFile#setNotifyInfo(NotifyInfo)
	 */
	public void setNotifyInfo(NotifyInfo info) throws CVSException {
		if (isManaged()) {
			EclipseSynchronizer.getInstance().setNotifyInfo(resource, info);
			// On an edit, the base should be cached
			// On an unedit, the base should be restored (and cleared?)
			// On a commit, the base should be cleared
		}
	}

	/**
	 * @see org.eclipse.team.internal.ccvs.core.ICVSFile#getNotifyInfo()
	 */
	public NotifyInfo getNotifyInfo() throws CVSException {
		if (isManaged()) {
			return EclipseSynchronizer.getInstance().getNotifyInfo(resource);		
		}
		return null;
	}

	/**
	 * @see org.eclipse.team.internal.ccvs.core.ICVSFile#setNotifyInfo(NotifyInfo)
	 */
	public void setBaserevInfo(BaserevInfo info) throws CVSException {
		if (isManaged()) {
			if (info == null) {
				EclipseSynchronizer.getInstance().deleteBaserevInfo(resource);
				EclipseSynchronizer.getInstance().deleteFileFromBaseDirectory(getIFile(), null);
			} else
				EclipseSynchronizer.getInstance().setBaserevInfo(resource, info);
		}
	}
	/**
	 * @see org.eclipse.team.internal.ccvs.core.ICVSFile#getNotifyInfo()
	 */
	public BaserevInfo getBaserevInfo() throws CVSException {
		if (isManaged()) {
			return EclipseSynchronizer.getInstance().getBaserevInfo(resource);
		}
		return null;
	}
	
	@Override
	public void edit(final int notifications, boolean notifyForWritable, IProgressMonitor monitor) throws CVSException {
		if (!notifyForWritable && !isReadOnly()) return;
		run(monitor1 -> {
			byte[] syncBytes = getSyncBytes();
			if (syncBytes == null || ResourceSyncInfo.isAddition(syncBytes)) return;
			
			// convert the notifications to internal form
			char[] internalFormat;
			if (notifications == NO_NOTIFICATION) {
				internalFormat = null;
			} else if (notifications == NOTIFY_ON_ALL) {
				internalFormat = NotifyInfo.ALL;
			} else {
				List<Character> notificationCharacters = new ArrayList<>();
				if ((notifications & NOTIFY_ON_EDIT) >0) 
					notificationCharacters.add(Character.valueOf(NotifyInfo.EDIT));
				if ((notifications & NOTIFY_ON_UNEDIT) >0) 
					notificationCharacters.add(Character.valueOf(NotifyInfo.UNEDIT));
				if ((notifications & NOTIFY_ON_COMMIT) >0) 
					notificationCharacters.add(Character.valueOf(NotifyInfo.COMMIT));
				internalFormat = new char[notificationCharacters.size()];
				for (int i = 0; i < internalFormat.length; i++) {
					internalFormat[i] = notificationCharacters.get(i).charValue();
				}
			}
			
			// record the notification
			NotifyInfo notifyInfo = new NotifyInfo(getName(), NotifyInfo.EDIT, new Date(), internalFormat);
			setNotifyInfo(notifyInfo);
			
			// Only record the base if the file is not modified
			if (!isModified(null)) {
				EclipseSynchronizer.getInstance().copyFileToBaseDirectory(getIFile(), monitor1);
				setBaserevInfo(new BaserevInfo(getName(), ResourceSyncInfo.getRevision(syncBytes)));
			}
			
			try {
				// allow editing
				setReadOnly(false);
			} catch (CVSException e) {
				// Just log and keep going
				CVSProviderPlugin.log(e);
			}
		}, monitor);
		
	}

	@Override
	public void unedit(IProgressMonitor monitor) throws CVSException {
		if (isReadOnly()) return;
		run(monitor1 -> {
			// record the notification
			NotifyInfo info = getNotifyInfo();
			if (info != null && info.getNotificationType() == NotifyInfo.EDIT) {
				info = null;
			} else {
				info = new NotifyInfo(getName(), NotifyInfo.UNEDIT, new Date(), null);
			}
			setNotifyInfo(info);
				
			if (isModified(null)) {
				ResourceSyncInfo syncInfo = getSyncInfo();
				BaserevInfo baserevInfo = getBaserevInfo();
				EclipseSynchronizer.getInstance().restoreFileFromBaseDirectory(getIFile(), monitor1);
				// reset any changes that may have been merged from the server
				if (!syncInfo.getRevision().equals(baserevInfo.getRevision())) {
					MutableResourceSyncInfo newInfo = syncInfo.cloneMutable();
					newInfo.setRevision(baserevInfo.getRevision());
					newInfo.setTimeStamp(getTimeStamp());
					newInfo.setDeleted(false);
					setSyncInfo(newInfo, ICVSFile.CLEAN);
				} else {
					// an unedited file is no longer modified
					EclipseSynchronizer.getInstance().setModified(EclipseFile.this, CLEAN);
				}
			} else {
				// We still need to report a state change
				setSyncBytes(getSyncBytes(), ICVSFile.CLEAN);
			}
			setBaserevInfo(null);
				
			try {
				// prevent editing
				setReadOnly(true);
			} catch (CVSException e) {
				// Just log and keep going
				CVSProviderPlugin.log(e);
			}
		}, monitor);
	}

	@Override
	public void notificationCompleted() throws CVSException {
		EclipseSynchronizer.getInstance().deleteNotifyInfo(resource);
	}

	@Override
	public NotifyInfo getPendingNotification() throws CVSException {
		return getNotifyInfo();
	}
	
	@Override
	public void checkedIn(String entryLine, boolean commit) throws CVSException {
		ResourceSyncInfo oldInfo = getSyncInfo();
		ResourceSyncInfo newInfo = null;
		int modificationState = ICVSFile.CLEAN;
		if (entryLine == null) {
			// cvs commit: the file contents matched the server contents so no entry line was sent
			if (oldInfo == null) return;
			// We should never make the timestamp go backwards so we'll set
			// the entry line timestamp to match that of the file
			if(! oldInfo.isAdded()) {
				MutableResourceSyncInfo mutable = oldInfo.cloneMutable();
				mutable.setTimeStamp(getTimeStamp(), true /* clear merged */);
				newInfo = mutable;
			}
			// (modified = false) the file will be no longer modified
		} else if (oldInfo == null) {
			// cvs add: addition of a file
			newInfo = new ResourceSyncInfo(entryLine, null);
			// an added file should show up as modified
			modificationState = ICVSFile.DIRTY;
		} else {
			// cvs commit: commit of a changed file
			// cvs update: update of a file whose contents match the server contents
			Date timeStamp;
			if (commit) {
				// This is a commit. Put the file timestamp in the entry
				timeStamp = getTimeStamp();
			} else {
				// This is an update. We need to change the tiemstamp in the
				// entry file to match the file timestamp returned by Java
				timeStamp = oldInfo.getTimeStamp();
				if (timeStamp == null) {
					timeStamp = getTimeStamp();
				} else {
					// First, set the timestamp of the file to the timestamp from the entry
					// There is a chance this will do nothing as the call to Java on some
					// file systems munges the timestamps
					setTimeStamp(timeStamp);
					// To compensate for the above, reset the timestamp in the entry
					// to match the timestamp in the file
					timeStamp = getTimeStamp();
				}
			}
			newInfo = new ResourceSyncInfo(entryLine, timeStamp);
			
		}
		//see bug 106876
		if (newInfo != null){
			CVSTag tag = newInfo.getTag();
			if(tag != null && CVSEntryLineTag.BASE.getName().equals(tag.getName())){
				newInfo = newInfo.cloneMutable();
				((MutableResourceSyncInfo)newInfo).setTag(oldInfo.getTag());
			}
			setSyncInfo(newInfo, modificationState);
		}
		clearCachedBase();
	}
	
	private void clearCachedBase() throws CVSException {
		BaserevInfo base = getBaserevInfo();
		if (base != null) {
			setBaserevInfo(null);
			try {
				setReadOnly(true);
			} catch (CVSException e) {
				// Just log and keep going
				CVSProviderPlugin.log(e);
			}
		} else {
			// Check to see if watch-edit is enabled for the project
			CVSTeamProvider provider = (CVSTeamProvider)RepositoryProvider.getProvider(resource.getProject(), CVSProviderPlugin.getTypeId());
			if (provider != null && provider.isWatchEditEnabled()) {
				try {
					setReadOnly(true);
				} catch (CVSException e) {
					// Just log and keep going
					CVSProviderPlugin.log(e);
				}
			}
		}
	}

	@Override
	public void unmanage(IProgressMonitor monitor) throws CVSException {
		run(monitor1 -> {
			EclipseFile.super.unmanage(monitor1);
			clearCachedBase();
		}, monitor);
	}
	
	@Override
	public boolean isEdited() throws CVSException {
		return EclipseSynchronizer.getInstance().isEdited(getIFile());
	}

	@Override
	public void setSyncInfo(ResourceSyncInfo info, int modificationState) throws CVSException {
		setSyncBytes(info.getBytes(), info, modificationState);
	}
	
	@Override
	public void setSyncBytes(byte[] syncBytes, int modificationState) throws CVSException {
		setSyncBytes(syncBytes, null, modificationState);
	}
	
	/*
	 * @see org.eclipse.team.internal.ccvs.core.resources.EclipseResource#setSyncBytes(byte[], int)
	 */
	private void setSyncBytes(byte[] syncBytes, ResourceSyncInfo info, int modificationState) throws CVSException {
		Assert.isNotNull(syncBytes);
		setSyncBytes(syncBytes);
		EclipseSynchronizer.getInstance().setModified(this, modificationState);
	}
	
	public void handleModification(boolean forAddition) throws CVSException {
		if (isIgnored()) {			
			// Special case handling for when a resource passes from the un-managed state
			// to the ignored state (e.g. ignoring the ignore file). Parent dirty state must be
			// recalculated but since the resource's end state is ignored there is a lot of code
			// in the plugin that simply disregards the change to the resource.
			// There may be a better was of handling resources that transition from un-managed to
			// ignored but for now this seems like the safest change. 
			if(! resource.isDerived()) {
				EclipseSynchronizer.getInstance().setModified(this, CLEAN);
			}
			return;
		} 
		// set the modification state to what it really is and return true if the modification state changed
		EclipseSynchronizer.getInstance().setModified(this, UNKNOWN);
	}

	@Override
	public String getRepositoryRelativePath() throws CVSException {
		if (!isManaged()) return null;
		String parentPath = getParent().getRepositoryRelativePath();
		if (parentPath == null) return null;
		return parentPath + Session.SERVER_SEPARATOR + getName();
	}
	
	protected boolean isDirty() throws CVSException {
		boolean dirty;
		byte[] syncBytes = getSyncBytes();
		if (syncBytes == null) {
			dirty = exists();
		} else {
			// isMerged() must be called because when a file is updated and merged by the cvs server the timestamps
			// are equal. Merged files should however be reported as dirty because the user should take action and commit
			// or review the merged contents.
			if (ResourceSyncInfo.isAddition(syncBytes)
					|| ResourceSyncInfo.isMerge(syncBytes)
					|| ResourceSyncInfo.wasDeleted(syncBytes) || !exists()) {
				dirty = true;
			} else {
				// TODO: non-optimal as ResourceSyncInfo is created each time
				ResourceSyncInfo info = new ResourceSyncInfo(syncBytes);
				dirty = !getTimeStamp().equals(info.getTimeStamp());
			}
		}
		return dirty;
	}

}