/*
 * Copyright 2013-2017 consulo.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package consulo.csharp.ide.completion;

import static com.intellij.patterns.StandardPatterns.psiElement;

import org.jetbrains.annotations.NotNull;
import consulo.csharp.lang.psi.CSharpReferenceExpression;
import consulo.csharp.lang.psi.CSharpReferenceExpressionEx;
import consulo.csharp.lang.psi.CSharpSoftTokens;
import consulo.csharp.lang.psi.CSharpTokens;
import consulo.csharp.module.extension.CSharpLanguageVersion;
import consulo.csharp.module.extension.CSharpModuleUtil;
import com.intellij.codeInsight.completion.CompletionContributor;
import com.intellij.codeInsight.completion.CompletionParameters;
import com.intellij.codeInsight.completion.CompletionResultSet;
import com.intellij.codeInsight.completion.CompletionType;
import com.intellij.psi.PsiElement;
import com.intellij.util.ProcessingContext;
import consulo.annotations.RequiredReadAction;
import consulo.codeInsight.completion.CompletionProvider;

/**
 * @author VISTALL
 * @since 03.01.15
 */
public class CSharpLinqCompletionContributor extends CompletionContributor
{
	public CSharpLinqCompletionContributor()
	{
		extend(CompletionType.BASIC, psiElement(CSharpTokens.IDENTIFIER).withParent(CSharpReferenceExpressionEx.class), new CompletionProvider()
		{
			@RequiredReadAction
			@Override
			public void addCompletions(@NotNull CompletionParameters parameters, ProcessingContext context, @NotNull CompletionResultSet result)
			{
				PsiElement position = parameters.getPosition();
				if(!CSharpModuleUtil.findLanguageVersion(position).isAtLeast(CSharpLanguageVersion._3_0))
				{
					return;
				}
				CSharpReferenceExpressionEx parent = (CSharpReferenceExpressionEx) position.getParent();
				if(parent.getQualifier() != null || parent.kind() != CSharpReferenceExpression.ResolveToKind.ANY_MEMBER)
				{
					return;
				}

				CSharpCompletionUtil.elementToLookup(result, CSharpSoftTokens.FROM_KEYWORD, null, null);
			}
		});
	}

	@RequiredReadAction
	@Override
	public void fillCompletionVariants(CompletionParameters parameters, CompletionResultSet result)
	{
		super.fillCompletionVariants(parameters, CSharpCompletionSorting.modifyResultSet(parameters, result));
	}
}