/*
 * 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 com.google.common.collect.ImmutableMap;
import org.sonar.check.Rule;
import org.sonar.java.model.ModifiersUtils;
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.IdentifierTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.Modifier;
import org.sonar.plugins.java.api.tree.ModifiersTree;
import org.sonar.plugins.java.api.tree.ParameterizedTypeTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.TypeTree;
import org.sonar.plugins.java.api.tree.VariableTree;

import javax.annotation.Nullable;
import java.util.Map;

@Rule(key = "S1319")
public class CollectionImplementationReferencedCheck extends BaseTreeVisitor implements JavaFileScanner {

  private static final String DEQUE = "Deque";
  private static final String LIST = "List";
  private static final String MAP = "Map";
  private static final String CONCURRENT_MAP = "ConcurrentMap";
  private static final String QUEUE = "Queue";
  private static final String SET = "Set";
  private static final String SORTED_MAP = "SortedMap";
  private static final String SORTED_SET = "SortedSet";

  private static final Map<String, String> MAPPING = ImmutableMap.<String, String> builder()
    .put("ArrayDeque", DEQUE)
    .put("ConcurrentLinkedDeque", DEQUE)

    .put("AbstractList", LIST)
    .put("AbstractSequentialList", LIST)
    .put("ArrayList", LIST)
    .put("CopyOnWriteArrayList", LIST)
    .put("LinkedList", LIST)

    .put("AbstractMap", MAP)
    .put("EnumMap", MAP)
    .put("HashMap", MAP)
    .put("Hashtable", MAP)
    .put("IdentityHashMap", MAP)
    .put("LinkedHashMap", MAP)
    .put("WeakHashMap", MAP)

    .put("ConcurrentHashMap", CONCURRENT_MAP)
    .put("ConcurrentSkipListMap", CONCURRENT_MAP)

    .put("AbstractQueue", QUEUE)
    .put("ConcurrentLinkedQueue", QUEUE)
    .put("SynchronousQueue", QUEUE)

    .put("AbstractSet", SET)
    .put("CopyOnWriteArraySet", SET)
    .put("EnumSet", SET)
    .put("HashSet", SET)
    .put("LinkedHashSet", SET)

    .put("TreeMap", SORTED_MAP)

    .put("TreeSet", SORTED_SET)
    .build();

  private JavaFileScannerContext context;

  @Override
  public void scanFile(final JavaFileScannerContext context) {
    this.context = context;
    scan(context.getTree());
  }

  @Override
  public void visitVariable(VariableTree tree) {
    super.visitVariable(tree);
    if (isPublic(tree.modifiers())) {
      checkIfAllowed(tree.type(), "The type of the \"" + tree.simpleName() + "\" object ");
    }
  }

  @Override
  public void visitMethod(MethodTree tree) {
    super.visitMethod(tree);
    if (isPublic(tree.modifiers())) {
      checkIfAllowed(tree.returnType(), "The return type of this method ");
      for (VariableTree variableTree : tree.parameters()) {
        checkIfAllowed(variableTree.type(), "The type of the \"" + variableTree.simpleName() + "\" object ");
      }
    }
  }

  private void checkIfAllowed(@Nullable TypeTree tree, String messagePrefix) {
    if (tree == null) {
      return;
    }
    String collectionImplementation = getTypeIdentifier(tree);
    String collectionInterface = MAPPING.get(collectionImplementation);

    if (collectionInterface != null) {
      context.reportIssue(this, tree, messagePrefix + messageRemainder(collectionImplementation, collectionInterface));
    }
  }

  private static boolean isPublic(ModifiersTree modifiers) {
    return ModifiersUtils.hasModifier(modifiers, Modifier.PUBLIC);
  }

  private static String getTypeIdentifier(Tree tree) {
    Tree actualTree = tree.is(Tree.Kind.PARAMETERIZED_TYPE) ? ((ParameterizedTypeTree) tree).type() : tree;
    return actualTree.is(Tree.Kind.IDENTIFIER) ? ((IdentifierTree) actualTree).name() : null;
  }

  private static String messageRemainder(String collectionImplementation, String collectionInterface) {
    return "should be an interface such as \"" + collectionInterface + "\" rather than the implementation \"" + collectionImplementation + "\".";
  }

}