/*
 * SonarQube Java
 * Copyright (C) 2012-2016 SonarSource SA
 * mailto:contact AT sonarsource DOT com
 *
 * 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  02110-1301, USA.
 */
package org.sonar.java.checks.naming;

import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.java.RspecKey;
import org.sonar.plugins.java.api.JavaFileScanner;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.ForEachStatement;
import org.sonar.plugins.java.api.tree.ForStatementTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.VariableTree;

import java.util.regex.Pattern;

@Rule(key = "S00117")
@RspecKey("S117")
public class BadLocalVariableNameCheck  extends BaseTreeVisitor implements JavaFileScanner {

  private static final String DEFAULT_FORMAT = "^[a-z][a-zA-Z0-9]*$";

  @RuleProperty(
    key = "format",
    description = "Regular expression used to check the names against.",
    defaultValue = "" + DEFAULT_FORMAT)
  public String format = DEFAULT_FORMAT;

  private Pattern pattern = null;
  private JavaFileScannerContext context;

  @Override
  public void scanFile(JavaFileScannerContext context) {
    if (pattern == null) {
      pattern = Pattern.compile(format, Pattern.DOTALL);
    }
    this.context = context;
    scan(context.getTree());
  }

  @Override
  public void visitClass(ClassTree tree) {
    for (Tree member : tree.members()) {
      if (member.is(Tree.Kind.VARIABLE)) {
        // skip check of field
        scan(((VariableTree) member).initializer());
      } else {
        scan(member);
      }
    }
  }

  @Override
  public void visitForStatement(ForStatementTree tree) {
    scan(tree.statement());
  }

  @Override
  public void visitForEachStatement(ForEachStatement tree) {
    scan(tree.statement());
  }

  @Override
  public void visitVariable(VariableTree tree) {
    if (!pattern.matcher(tree.simpleName().name()).matches()) {
      context.reportIssue(this, tree.simpleName(), "Rename this local variable name to match the regular expression '" + format + "'.");
    }
    super.visitVariable(tree);
  }

}