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/*
 * Sonar Erlang Plugin
 * Copyright (C) 2012 Tamas Kende
 * [email protected]
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */
package org.sonar.erlang.checks;

import com.sonar.sslr.api.AstNode;
import com.sonar.sslr.api.GenericTokenType;
import com.sonar.sslr.api.Token;
import com.sonar.sslr.api.Trivia;
import com.sonar.sslr.squid.checks.SquidCheck;
import org.sonar.check.BelongsToProfile;
import org.sonar.check.Cardinality;
import org.sonar.check.Priority;
import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.erlang.api.ErlangGrammar;

@Rule(key = "MultipleBlankLines", priority = Priority.MAJOR, cardinality = Cardinality.SINGLE)
@BelongsToProfile(title = CheckList.REPOSITORY_NAME, priority = Priority.MAJOR)
public class MultipleBlankLinesCheck extends SquidCheck {

  @RuleProperty(key = "maxBlankLinesInsideFunctions", defaultValue = "1")
  public int maxBlankLinesInsideFunctions = 1;

  @RuleProperty(key = "maxBlankLinesOutsideFunctions", defaultValue = "2")
  public int maxBlankLinesOutsideFunctions = 2;

  private Token previousToken;

  @Override
  public void init() {
    subscribeTo(GenericTokenType.IDENTIFIER);
  }

  @Override
  public void visitNode(AstNode ast) {
    if (!ast.getToken().isGeneratedCode()) {
      if (previousToken == null
        || (previousToken != null && previousToken.getLine() != ast.getToken()
            .getLine())) {
        int previousLine = (previousToken != null) ? previousToken.getLine() : 0;

        if (checkBlankLines(ast, previousLine)) {
          getContext().createLineViolation(this,
              "Too many blank lines found, the threshold is {0}.",
              ast.getToken().getLine(), getMaxFor(ast));
        }
      }
      previousToken = ast.getLastToken();
    }

  }

  private boolean compare(int line1, int line2, int comp) {
    return (line1 - line2 - 1 > comp);
  }

  private int getMaxFor(AstNode ast) {
    if (ast.findFirstParent(getContext().getGrammar().clauseBody) != null) {
      return maxBlankLinesInsideFunctions;
    } else {
      return maxBlankLinesOutsideFunctions;
    }
  }

  private boolean checkTrivias(int previousLine, Token token, int compTo) {
    int prevLine = previousLine;
    for (Trivia trivias : token.getTrivia()) {
      if (compare(trivias.getToken().getLine(), prevLine, compTo)) {
        return true;
      }
      prevLine = trivias.getToken().getLine();
    }
    return compare(token.getLine(), prevLine, compTo);
  }

  private boolean checkBlankLines(AstNode ast, int previousLine) {
    int compTo = getMaxFor(ast);

    boolean check = compare(ast.getToken().getLine(), previousLine, compTo);
    if (check) {
      Token tokenWithTrivias = (ast.getToken().hasTrivia()) ? ast.getToken() : ast
          .previousAstNode().getToken();
      if (tokenWithTrivias.hasTrivia()) {
        return checkTrivias(previousLine, tokenWithTrivias, compTo);
      }
    }
    return check;
  }

}