/*
 * Copyright 2011 The authors
 * 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 com.intellij.lang.ognl.completion;

import com.intellij.codeInsight.completion.*;
import com.intellij.codeInsight.lookup.LookupElementBuilder;
import com.intellij.lang.ognl.psi.OgnlStringLiteral;
import com.intellij.lang.ognl.psi.OgnlVariableExpression;
import com.intellij.openapi.project.DumbAware;
import com.intellij.patterns.PsiElementPattern;
import com.intellij.psi.PsiElement;
import com.intellij.util.ProcessingContext;
import org.jetbrains.annotations.NotNull;

import static com.intellij.lang.ognl.psi.OgnlKeyword.*;
import static com.intellij.patterns.PlatformPatterns.psiElement;
import static com.intellij.patterns.StandardPatterns.not;
import static com.intellij.patterns.StandardPatterns.or;

/**
 * @author Yann Cébron
 */
public class OgnlKeywordCompletionContributor extends CompletionContributor implements DumbAware {

  private static final String[] ALL = new String[]{
      SHL, SHR, USHR,
      AND, BAND, OR, BOR, XOR, EQ, NEQ, LT, LTE, GT, GTE,
      NOT_IN, IN, NEW,
      TRUE, FALSE, NULL, INSTANCEOF
  };

  private static final PsiElementPattern.Capture<PsiElement> STRING_LITERAL =
      psiElement().inside(OgnlStringLiteral.class);

  private static final PsiElementPattern.Capture<PsiElement> VARIABLE_EXPRESSION =
      psiElement().inside(OgnlVariableExpression.class);

  public OgnlKeywordCompletionContributor() {
    extend(CompletionType.BASIC,
           not(or(STRING_LITERAL, VARIABLE_EXPRESSION)),
           new CompletionProvider<CompletionParameters>() {
             @Override
             protected void addCompletions(@NotNull final CompletionParameters completionParameters,
                                           final ProcessingContext processingContext,
                                           @NotNull final CompletionResultSet completionResultSet) {
               for (final String keyword : ALL) {
                 final LookupElementBuilder builder = LookupElementBuilder.create(keyword).setBold();
                 completionResultSet.addElement(builder);
               }
             }
           });
  }

}