r/org.eclipse.statet.r.ui/src/org/eclipse/statet/r/ui/sourceediting/RPathCompletionComputer.java

/*=============================================================================#
 # Copyright (c) 2007, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.r.ui.sourceediting;

import java.util.List;

import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.core.filesystem.URIUtil;
import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.TextUtilities;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;
import org.eclipse.statet.jcommons.text.core.TextRegion;
import org.eclipse.statet.jcommons.text.core.input.OffsetStringParserInput;
import org.eclipse.statet.jcommons.text.core.input.TextParserInput;
import org.eclipse.statet.jcommons.ts.core.Tool;

import org.eclipse.statet.ecommons.net.resourcemapping.core.IResourceMapping;
import org.eclipse.statet.ecommons.net.resourcemapping.core.IResourceMappingManager;
import org.eclipse.statet.ecommons.net.resourcemapping.core.ResourceMappingOrder;
import org.eclipse.statet.ecommons.net.resourcemapping.core.ResourceMappingUtils;

import org.eclipse.statet.ltk.model.core.element.SourceUnit;
import org.eclipse.statet.ltk.model.core.element.WorkspaceSourceUnit;
import org.eclipse.statet.ltk.ui.sourceediting.ISourceEditor;
import org.eclipse.statet.ltk.ui.sourceediting.assist.AssistInvocationContext;
import org.eclipse.statet.ltk.ui.sourceediting.assist.AssistProposalCollector;
import org.eclipse.statet.ltk.ui.sourceediting.assist.ContentAssist;
import org.eclipse.statet.ltk.ui.sourceediting.assist.PathCompletionComputor;
import org.eclipse.statet.ltk.ui.sourceediting.assist.SourceProposal.ProposalParameters;
import org.eclipse.statet.nico.ui.console.ConsolePageEditor;
import org.eclipse.statet.r.console.core.RProcess;
import org.eclipse.statet.r.core.RUtil;
import org.eclipse.statet.r.core.rlang.RTerminal;
import org.eclipse.statet.r.core.rsource.RLexer;


/**
 * Completion computer for path in R code.
 * 
 * Supports workspace properties of a R tool process
 */
@NonNullByDefault
public class RPathCompletionComputer extends PathCompletionComputor {
	
	
	private @Nullable RProcess associatedTool;
	
	private @Nullable IContainer baseResource;
	private @Nullable IFileStore baseFileStore;
	
	private final RLexer rLexer= new RLexer(RLexer.ENABLE_QUICK_CHECK);
	
	
	public RPathCompletionComputer() {
	}
	
	
	@Override
	public void onSessionStarted(final ISourceEditor editor, final ContentAssist assist) {
		this.associatedTool= null;
		this.baseResource= null;
		this.baseFileStore= null;
		if (editor instanceof ConsolePageEditor) {
			final Tool tool= editor.getAdapter(Tool.class);
			if (tool instanceof RProcess) {
				this.associatedTool= (RProcess) tool;
			}
		}
		else {
			final SourceUnit su= editor.getSourceUnit();
			if (su instanceof WorkspaceSourceUnit) {
				IContainer baseResource= null;
				final IResource resource= ((WorkspaceSourceUnit)su).getResource();
//				final IRProject rProject= RProjects.getRProject(resource.getProject());
//				if (rProject != null) {
//					this.baseResource= rProject.getRawBuildpath();
//				}
				if (baseResource == null) {
					baseResource= resource.getParent();
				}
				if (baseResource != null) {
					try {
						this.baseResource= baseResource;
						this.baseFileStore= EFS.getStore(baseResource.getLocationURI());
					}
					catch (final CoreException e) {
					}
				}
			}
		}
		
		super.onSessionStarted(editor, assist);
	}
	
	@Override
	public void onSessionEnded() {
		super.onSessionEnded();
		this.associatedTool= null;
	}
	
	@Override
	protected boolean getIsWindows() {
		final RProcess associatedTool= this.associatedTool;
		if ((associatedTool != null)) {
			return associatedTool.getWorkspaceData().isWindows();
		}
		return super.getIsWindows();
	}
	
	@Override
	protected char getDefaultFileSeparator() {
		final RProcess associatedTool= this.associatedTool;
		if (associatedTool != null) {
			return associatedTool.getWorkspaceData().getFileSeparator();
		}
		return super.getDefaultFileSeparator();
	}
	
	@Override
	protected @Nullable TextRegion getContentRegion(final AssistInvocationContext context, final int mode)
			throws BadLocationException {
		final IDocument document= context.getSourceViewer().getDocument();
		final int offset= context.getInvocationOffset();
		final ITypedRegion partition= TextUtilities.getPartition(document,
				context.getEditor().getDocumentContentInfo().getPartitioning(), offset, true);
		this.rLexer.reset(new OffsetStringParserInput(
						document.get(partition.getOffset(), partition.getLength()),
						partition.getOffset() )
				.init(partition.getOffset(), partition.getOffset() + partition.getLength()) );
		switch (this.rLexer.next()) {
		case STRING_D:
		case STRING_S:
			return this.rLexer.getTextRegion();
		case STRING_R:
			return this.rLexer.getTextRegion();
		default:
			return null;
		}
	}
	
	@Override
	protected @Nullable IPath getRelativeBasePath() {
		{	final RProcess associatedTool= this.associatedTool;
			if (associatedTool != null) {
				final IFileStore wd= associatedTool.getWorkspaceData().getWorkspaceDir();
				if (wd != null) {
					return URIUtil.toPath(wd.toURI());
				}
				return null;
			}
		}
		{	final IContainer baseResource= this.baseResource;
			if (baseResource != null) {
				return baseResource.getLocation();
			}
		}
		return null;
	}
	
	@Override
	protected @Nullable IFileStore getRelativeBaseStore() {
		{	final RProcess associatedTool= this.associatedTool;
			if (associatedTool != null) {
				return associatedTool.getWorkspaceData().getWorkspaceDir();
			}
		}
		{	final IFileStore baseFileStore= this.baseFileStore;
			if (baseFileStore != null) {
				return baseFileStore;
			}
		}
		return null;
	}
	
	@Override
	protected @Nullable IFileStore resolveStore(final IPath path) throws CoreException {
		{	final RProcess associatedTool= this.associatedTool;
			if (associatedTool != null) {
				return associatedTool.getWorkspaceData().toFileStore(path);
			}
		}
		return super.resolveStore(path);
	}
	
	@Override
	protected void tryAlternative(final AssistInvocationContext context,
			final IPath path,
			final int startOffset, final String segmentPrefix, final String completionPrefix,
			final AssistProposalCollector proposals) throws CoreException {
		final RProcess associatedTool= this.associatedTool;
		if (associatedTool != null) {
			final String address= associatedTool.getWorkspaceData().getRemoteAddress();
			if (address != null) {
				final IResourceMappingManager rmManager= ResourceMappingUtils.getManager();
				if (rmManager != null) {
					final ProposalParameters<?> parameters= createProposalParameters(
							context, startOffset, segmentPrefix );
					
					final List<IResourceMapping> mappings= rmManager
							.getResourceMappingsFor(address, ResourceMappingOrder.REMOTE);
					for (final IResourceMapping mapping : mappings) {
						IPath remotePath= mapping.getRemotePath();
						if (path.isEmpty()) {
							// remotePath
						}
						else if (path.isPrefixOf(remotePath)) {
							remotePath= remotePath.setDevice(null).makeRelative().removeFirstSegments(path.segmentCount());
						}
						else {
							continue;
						}
						String name= remotePath.segment(0);
						if (name == null) {
							name= ""; //$NON-NLS-1$
						}
						if (parameters.matchesNamePattern(name)) {
							proposals.add(new ResourceCompletionProposal(parameters,
									mapping.getFileStore(), remotePath.toString(), completionPrefix,
									null ));
						}
					}
					return;
				}
			}
		}
	}
	
	@Override
	protected @Nullable String getPrefix(final AssistInvocationContext context,
			final TextRegion contentRegion, final int offset)
			throws BadLocationException {
		if (this.rLexer.getType() == RTerminal.STRING_R) {
			return super.getPrefix(context, contentRegion, offset);
		}
		final RLexer textLexer= new RLexer();
		final TextParserInput input= this.rLexer.getInput();
		textLexer.reset(input.init(input.getStartIndex(), offset));
		switch (textLexer.next()) {
		case STRING_D:
		case STRING_S:
			return super.checkPrefix(textLexer.getText());
		default:
			return null;
		}
	}
	
	@Override
	protected String checkPathCompletion(final IDocument document, final int completionOffset,
			String completion) {
		if (this.rLexer.getType() == RTerminal.STRING_R) {
			return completion;
		}
		completion= RUtil.escapeCompletely(completion);
		int existingBackslashCount= 0;
		if (completionOffset >= 1) {
			try {
				if (document.getChar(completionOffset - 1) == '\\') {
					existingBackslashCount++;
					if (completionOffset >= 2) {
						if (document.getChar(completionOffset - 2) == '\\') {
							existingBackslashCount++;
						}
					}
				}
			}
			catch (final BadLocationException e) {}
		}
		final boolean startsWithBackslash= (completion.length() >= 2 && 
				completion.charAt(0) == '\\' && completion.charAt(1) == '\\');
		if ((existingBackslashCount % 2) == 1) {
			if (startsWithBackslash) {
				completion= completion.substring(1);
			}
			else {
				completion= '\\' + completion;
			}
		}
		else if (existingBackslashCount > 0) {
			if (startsWithBackslash) {
				completion= completion.substring(2);
			}
		}
		return completion;
	}
	
}