/*
 * 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;

import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.java.checks.helpers.ExpressionsHelper;
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.MemberSelectExpressionTree;

import java.util.HashSet;
import java.util.Set;

@Rule(key = "S1191")
public class SunPackagesUsedCheck extends BaseTreeVisitor implements JavaFileScanner {

  private Set<Integer> reportedLines = new HashSet<>();

  private static final String DEFAULT_EXCLUDE = "";

  @RuleProperty(
      key = "Exclude",
      description = "Comma separated list of Sun packages to be ignored by this rule. Example: com.sun.jna,sun.misc",
      defaultValue = "" + DEFAULT_EXCLUDE)
  public String exclude = DEFAULT_EXCLUDE;
  private String[] excludePackages = null;
  private JavaFileScannerContext context;

  @Override
  public void scanFile(JavaFileScannerContext context) {
    this.context = context;
    reportedLines.clear();
    excludePackages = exclude.split(",");
    scan(context.getTree());
  }

  @Override
  public void visitMemberSelectExpression(MemberSelectExpressionTree tree) {
    String reference = ExpressionsHelper.concatenate(tree);
    if (!isExcluded(reference)) {
      int line = tree.firstToken().line();
      if (!reportedLines.contains(line) && isSunClass(reference)) {
        context.addIssue(line, this, "Replace this usage of Sun classes by ones from the Java API.");
        reportedLines.add(line);
      }
      super.visitMemberSelectExpression(tree);
    }
  }

  private static boolean isSunClass(String reference) {
    return "com.sun".equals(reference) || reference.matches("sun\\.[^\\.]*");
  }

  private boolean isExcluded(String reference) {
    for (String str : excludePackages) {
      if (!str.isEmpty() && reference.startsWith(str)) {
        return true;
      }
    }
    return false;
  }
}