private ICompletionProposal createProposal(ContentAssistContext context, String name, String value,
		String description, String rawTemplate, Image image, boolean isGenericProposal) {

	TemplateContextType contextType = getTemplateContextType();
	IXtextDocument document = context.getDocument();
	TemplateContext tContext = new DocumentTemplateContext(contextType, document, context.getOffset(), 0);
	Region replaceRegion = context.getReplaceRegion();

	// pre-populate ${name} and ${value} with given args
	if (isGenericProposal) {
		tContext.setVariable("name", name);
	}
	tContext.setVariable("value", value);

	return new StyledTemplateProposal(context, name, description, rawTemplate, isGenericProposal, tContext,
			replaceRegion, image);
}
 

/**
 * @see msi.gama.lang.gaml.ui.editor.IGamlEditor#applyTemplate(org.eclipse.jface.text.templates.Template)
 */

public void applyTemplateAtTheEnd(final Template t) {

	try {
		final IDocument doc = getDocument();
		int offset = doc.getLineOffset(doc.getNumberOfLines() - 1);
		doc.replace(offset, 0, "\n\n");
		offset += 2;
		final int length = 0;
		final Position pos = new Position(offset, length);
		final XtextTemplateContextType ct = new XtextTemplateContextType();
		final DocumentTemplateContext dtc = new DocumentTemplateContext(ct, doc, pos);
		final IRegion r = new Region(offset, length);
		final TemplateProposal tp = new TemplateProposal(t, dtc, r, null);
		tp.apply(getInternalSourceViewer(), (char) 0, 0, offset);
	} catch (final BadLocationException e) {
		e.printStackTrace();
	}
}
 

private boolean isReplacedAreaEmpty(TemplateContext context) {
	// don't trim the buffer if the replacement area is empty
	// case: surrounding empty lines with block
	if (context instanceof DocumentTemplateContext) {
		DocumentTemplateContext dtc= (DocumentTemplateContext) context;
		if (dtc.getStart() == dtc.getCompletionOffset())
			try {
				IDocument document= dtc.getDocument();
				int lineOffset= document.getLineInformationOfOffset(dtc.getStart()).getOffset();
				//only if we are at the beginning of the line
				if (lineOffset != dtc.getStart())
					return false;

				//Does the selection only contain whitespace characters?
				if (document.get(dtc.getStart(), dtc.getEnd() - dtc.getStart()).trim().length() == 0)
					return true;
			} catch (BadLocationException x) {
				// ignore - this may happen when the document was modified after the initial invocation, and the
				// context does not track the changes properly - don't trim in that case
				return true;
			}
	}
	return false;
}
 

protected boolean isReplacedAreaEmpty(TemplateContext context) {
	// don't trim the buffer if the replacement area is empty
	// case: surrounding empty lines with block
	if (context instanceof DocumentTemplateContext) {
		DocumentTemplateContext dtc= (DocumentTemplateContext) context;
		if (dtc.getStart() == dtc.getCompletionOffset())
			try {
				IDocument document= dtc.getDocument();
				int lineOffset= document.getLineInformationOfOffset(dtc.getStart()).getOffset();
				//only if we are at the beginning of the line
				if (lineOffset != dtc.getStart())
					return false;

				//Does the selection only contain whitespace characters?
				if (document.get(dtc.getStart(), dtc.getEnd() - dtc.getStart()).trim().length() == 0)
					return true;
			} catch (BadLocationException x) {
				// ignore - this may happen when the document was modified after the initial invocation, and the
				// context does not track the changes properly - don't trim in that case
				return true;
			}
	}
	return false;
}
 

@Override
protected ICompletionProposal createProposal(Template template, TemplateContext context, IRegion region,
		int relevance) {
       if (context instanceof DocumentTemplateContext) {
           context = new SwaggerTemplateContext((DocumentTemplateContext) context);
       }
	return new StyledTemplateProposal(template, context, region, getImage(template), getTemplateLabel(template),
			relevance);
}
 

public void applyTemplate(final Template t) {
	// TODO Create a specific context type (with GAML specific variables ??)
	final XtextTemplateContextType ct = new XtextTemplateContextType();
	final IDocument doc = getDocument();
	final ITextSelection selection = (ITextSelection) getSelectionProvider().getSelection();
	final int offset = selection.getOffset();
	final int length = selection.getLength();
	final Position pos = new Position(offset, length);
	final DocumentTemplateContext dtc = new DocumentTemplateContext(ct, doc, pos);
	final IRegion r = new Region(offset, length);
	final TemplateProposal tp = new TemplateProposal(t, dtc, r, null);
	tp.apply(getInternalSourceViewer(), (char) 0, 0, offset);
}
 

@Override
protected boolean isValidTemplate(IDocument document, Template template, int offset, int length) {
	String[] contextIds= getContextTypeIds(document, offset);
	for (int i= 0; i < contextIds.length; i++) {
		if (contextIds[i].equals(template.getContextTypeId())) {
			DocumentTemplateContext context= getContext(document, template, offset, length);
			return context.canEvaluate(template) || isTemplateAllowed(context, template);
		}
	}
	return false;
}
 

/**
 * Check whether the template is allowed eventhough the context can't evaluate it. This is
 * needed because the Dropping of a template is more lenient than ctl-space invoked code assist.
 * 
 * @param context the template context
 * @param template the template
 * @return true if the template is allowed
 */
private boolean isTemplateAllowed(DocumentTemplateContext context, Template template) {
	int offset;
	try {
		if (template.getContextTypeId().equals(JavaDocContextType.ID)) {
			return (offset= context.getCompletionOffset()) > 0 && Character.isWhitespace(context.getDocument().getChar(offset - 1));
		} else {
			return ((offset= context.getCompletionOffset()) > 0 && !isTemplateNamePart(context.getDocument().getChar(offset - 1)));
		}
	} catch (BadLocationException e) {
	}
	return false;
}
 

/**
 * Get context
 * 
 * @param document the document
 * @param template the template
 * @param offset the offset
 * @param length the length
 * @return the context
 */
private DocumentTemplateContext getContext(IDocument document, Template template, final int offset, int length) {
	DocumentTemplateContext context;
	if (template.getContextTypeId().equals(JavaDocContextType.ID)) {
		context= new JavaDocContext(getContextTypeRegistry().getContextType(template.getContextTypeId()), document, new Position(offset, length), (ICompilationUnit) EditorUtility
				.getEditorInputJavaElement(fJavaEditor, true));
	} else {
		context= new JavaContext(getContextTypeRegistry().getContextType(template.getContextTypeId()), document, new Position(offset, length), (ICompilationUnit) EditorUtility.getEditorInputJavaElement(
				fJavaEditor, true));
	}
	return context;
}
 

/**
 * Computes the relevance to match the relevance values generated by the
 * core content assistant.
 *
 * @return a sensible relevance value.
 */
private int computeRelevance() {
	// see org.eclipse.jdt.internal.codeassist.RelevanceConstants
	final int R_DEFAULT= 0;
	final int R_INTERESTING= 5;
	final int R_CASE= 10;
	final int R_NON_RESTRICTED= 3;
	final int R_EXACT_NAME = 4;
	final int R_INLINE_TAG = 31;

	int base= R_DEFAULT + R_INTERESTING + R_NON_RESTRICTED;

	try {
		if (fContext instanceof DocumentTemplateContext) {
			DocumentTemplateContext templateContext= (DocumentTemplateContext) fContext;
			IDocument document= templateContext.getDocument();

			String content= document.get(fRegion.getOffset(), fRegion.getLength());
			if (content.length() > 0 && fTemplate.getName().startsWith(content))
				base += R_CASE;
			if (fTemplate.getName().equalsIgnoreCase(content))
				base += R_EXACT_NAME;
			if (fContext instanceof JavaDocContext)
				base += R_INLINE_TAG;
		}
	} catch (BadLocationException e) {
		// ignore - not a case sensitive match then
	}

	// see CompletionProposalCollector.computeRelevance
	// just under keywords, but better than packages
	final int TEMPLATE_RELEVANCE= 1;
	return base * 16 + TEMPLATE_RELEVANCE;
}
 

/**
 * Returns the offset of the range in the document that will be replaced by
 * applying this template.
 *
 * @return the offset of the range in the document that will be replaced by
 *         applying this template
 */
protected int getReplaceOffset() {
	int start;
	if (fContext instanceof DocumentTemplateContext) {
		DocumentTemplateContext docContext = (DocumentTemplateContext)fContext;
		start= docContext.getStart();
	} else {
		start= fRegion.getOffset();
	}
	return start;
}
 

/**
 * Returns the end offset of the range in the document that will be replaced
 * by applying this template.
 *
 * @return the end offset of the range in the document that will be replaced
 *         by applying this template
 */
protected final int getReplaceEndOffset() {
	int end;
	if (fContext instanceof DocumentTemplateContext) {
		DocumentTemplateContext docContext = (DocumentTemplateContext)fContext;
		end= docContext.getEnd();
	} else {
		end= fRegion.getOffset() + fRegion.getLength();
	}
	return end;
}
 

/**
 * Returns <code>true</code> if the proposal has a selection, e.g. will wrap some code.
 *
 * @return <code>true</code> if the proposals completion length is non zero
 * @since 3.2
 */
private boolean isSelectionTemplate() {
	if (fContext instanceof DocumentTemplateContext) {
		DocumentTemplateContext ctx= (DocumentTemplateContext) fContext;
		if (ctx.getCompletionLength() > 0)
			return true;
	}
	return false;
}
 

/**
 * Returns <code>true</code> if the proposal has a selection, e.g. will wrap some code.
 *
 * @return <code>true</code> if the proposals completion length is non zero
 * @since 3.2
 */
private boolean isSelectionTemplate() {
	if (getContext() instanceof DocumentTemplateContext) {
		DocumentTemplateContext ctx= (DocumentTemplateContext) getContext();
		if (ctx.getCompletionLength() > 0)
			return true;
	}
	return false;
}
 

private static List<CompletionItem> getGenericSnippets(SnippetCompletionContext scc) throws JavaModelException {
	List<CompletionItem> res = new ArrayList<>();
	CompletionContext completionContext = scc.getCompletionContext();
	char[] completionToken = completionContext.getToken();
	if (completionToken == null) {
		return Collections.emptyList();
	}
	int tokenLocation = completionContext.getTokenLocation();
	JavaContextType contextType = (JavaContextType) JavaLanguageServerPlugin.getInstance().getTemplateContextRegistry().getContextType(JavaContextType.ID_STATEMENTS);
	if (contextType == null) {
		return Collections.emptyList();
	}
	ICompilationUnit cu = scc.getCompilationUnit();
	IDocument document = new Document(cu.getSource());
	DocumentTemplateContext javaContext = contextType.createContext(document, completionContext.getOffset(), completionToken.length, cu);
	Template[] templates = null;
	if ((tokenLocation & CompletionContext.TL_STATEMENT_START) != 0) {
		templates = JavaLanguageServerPlugin.getInstance().getTemplateStore().getTemplates(JavaContextType.ID_STATEMENTS);
	} else {
		// We only support statement templates for now.
	}

	if (templates == null || templates.length == 0) {
		return Collections.emptyList();
	}

	for (Template template : templates) {
		if (!javaContext.canEvaluate(template)) {
			continue;
		}
		TemplateBuffer buffer = null;
		try {
			buffer = javaContext.evaluate(template);
		} catch (BadLocationException | TemplateException e) {
			JavaLanguageServerPlugin.logException(e.getMessage(), e);
			continue;
		}
		if (buffer == null) {
			continue;
		}
		String content = buffer.getString();
		if (Strings.containsOnlyWhitespaces(content)) {
			continue;
		}
		final CompletionItem item = new CompletionItem();
		item.setLabel(template.getName());
		item.setInsertText(content);
		item.setDetail(template.getDescription());
		setFields(item, cu);
		res.add(item);
	}

	return res;
}
 

public SwaggerTemplateContext(DocumentTemplateContext context) {
    super(context.getContextType(), context.getDocument(), context.getCompletionOffset(), context
            .getCompletionLength());
}
 

/**
 * Creates a concrete template context for the given region in the document. This involves finding out which
 * context type is valid at the given location, and then creating a context of this type. The default implementation
 * returns a <code>DocumentTemplateContext</code> for the context type at the given location.
 *
 * @param viewer the viewer for which the context is created
 * @param region the region into <code>document</code> for which the context is created
 * @return a template context that can handle template insertion at the given location, or <code>null</code>
 */
protected TemplateContext createContext(IRegion region, IDocument document) {
    TemplateContextType contextType = getContextType(region);
    if (contextType != null) {
        return new DocumentTemplateContext(contextType, document, region.getOffset(), region.getLength());
    }
    return null;
}