/*
 * Copyright 2012-2014 Sergey Ignatov
 *
 * 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 org.intellij.erlang.search;

import com.intellij.lang.HelpID;
import com.intellij.lang.cacheBuilder.WordOccurrence;
import com.intellij.lang.cacheBuilder.WordsScanner;
import com.intellij.lang.findUsages.FindUsagesProvider;
import com.intellij.openapi.util.TextRange;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.psi.ElementDescriptionUtil;
import com.intellij.psi.PsiElement;
import com.intellij.psi.tree.IElementType;
import com.intellij.usageView.UsageViewLongNameLocation;
import com.intellij.usageView.UsageViewNodeTextLocation;
import com.intellij.usageView.UsageViewTypeLocation;
import org.intellij.erlang.ErlangTypes;
import org.intellij.erlang.parser.ErlangLexer;
import org.intellij.erlang.psi.*;
import org.jetbrains.annotations.NotNull;

public class ErlangFindUsagesProvider implements FindUsagesProvider {
  @Override
  public WordsScanner getWordsScanner() {
    return (fileText, processor) -> {
      ErlangLexer lexer = new ErlangLexer();
      lexer.start(fileText);
      IElementType tokenType;
      while ((tokenType = lexer.getTokenType()) != null) {
        //TODO process occurrences in string literals and comments
        if (tokenType == ErlangTypes.ERL_ATOM_NAME || tokenType == ErlangTypes.ERL_VAR) {
          int tokenStart = lexer.getTokenStart();
          for (TextRange wordRange : StringUtil.getWordIndicesIn(lexer.getTokenText())) {
            int start = tokenStart + wordRange.getStartOffset();
            int end = tokenStart + wordRange.getEndOffset();
            processor.process(new WordOccurrence(fileText, start, end, WordOccurrence.Kind.CODE));
          }
        }
        lexer.advance();
      }
    };
  }

  @Override
  public boolean canFindUsagesFor(@NotNull PsiElement o) {
    return o instanceof ErlangFunction || o instanceof ErlangQVar
      || o instanceof ErlangRecordDefinition || o instanceof ErlangModule
      || o instanceof ErlangMacrosDefinition || o instanceof ErlangTypedExpr
      || o instanceof ErlangTypeDefinition || o instanceof ErlangQAtom
      ;
  }

  @Override
  public String getHelpId(@NotNull PsiElement psiElement) {
    return HelpID.FIND_OTHER_USAGES;
  }

  @NotNull
  @Override
  public String getType(@NotNull PsiElement element) {
    return ElementDescriptionUtil.getElementDescription(element, UsageViewTypeLocation.INSTANCE);
  }

  @NotNull
  @Override
  public String getDescriptiveName(@NotNull PsiElement element) {
    return ElementDescriptionUtil.getElementDescription(element, UsageViewLongNameLocation.INSTANCE);
  }

  @NotNull
  @Override
  public String getNodeText(@NotNull PsiElement element, boolean useFullName) {
    return ElementDescriptionUtil.getElementDescription(element, UsageViewNodeTextLocation.INSTANCE);
  }
}