/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * 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.coldFusion.UI.editorActions.completionProviders;

import com.intellij.codeInsight.completion.CompletionParameters;
import com.intellij.codeInsight.completion.CompletionProvider;
import com.intellij.codeInsight.completion.CompletionResultSet;
import com.intellij.codeInsight.lookup.LookupElementBuilder;
import com.intellij.coldFusion.model.info.CfmlLangInfo;
import com.intellij.coldFusion.model.psi.CfmlReference;
import com.intellij.coldFusion.model.psi.CfmlReferenceExpression;
import com.intellij.coldFusion.model.psi.impl.CfmlTagImpl;
import com.intellij.psi.PsiElement;
import com.intellij.util.ProcessingContext;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.Map;

/**
 * @author Nadya Zabrodina
 */
public class CfmlPredefinedVariablesCompletion extends CompletionProvider<CompletionParameters> {
  @Override
  protected void addCompletions(@NotNull CompletionParameters parameters,
                                ProcessingContext context,
                                @NotNull CompletionResultSet result) {
    Map<String, Integer> myPredefinedVariables = CfmlLangInfo.getInstance(parameters.getPosition().getProject()).getPredefinedVariables();
    String tagName = getNameForCfmlTag(parameters);
    for (String s : myPredefinedVariables.keySet()) {
      if (!s.contains("[x]")) {
        if (tagName != null && s.startsWith(tagName)) {
          result.addElement(LookupElementBuilder.create(s.substring(s.indexOf(".") + 1)).withCaseSensitivity(false));
        }
        else if (tagName == null &&
                 !result.getPrefixMatcher().getPrefix().isEmpty() &&
                 parameters.getPosition().getParent() instanceof CfmlReference) {
          result.addElement(LookupElementBuilder.create(s).withCaseSensitivity(false));
        }
      }
    }
  }

  @Nullable
  private static String getNameForCfmlTag(@NotNull CompletionParameters pars) {
    PsiElement elem = pars.getPosition().getParent().getFirstChild();
    if (elem instanceof CfmlReferenceExpression) {
      PsiElement resElem = ((CfmlReferenceExpression)elem).resolve();
      if (resElem != null) {
        PsiElement parent = resElem.getParent();
        if (!(parent instanceof CfmlTagImpl)) {
          return null;
        }
        String name = ((CfmlTagImpl)parent).getTagName();
        return name.startsWith("cf") ? name.substring(2) : name;
      }
    }
    return null;
  }
}