content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 com.datastax.oss.driver.internal.mapper.processor;
  
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.Objects;
  import java.util.Set;
  import javax.annotation.processing.Messager;
  import javax.lang.model.element.Element;
  import javax.tools.Diagnostic;
  
  /** Wraps {@link Messager} to provide convenience methods. */
  public class DecoratedMessager {
  
    private final Messager messager;
    private final Set<MessageId> emittedMessages = new HashSet<>();
  
    public DecoratedMessager(Messager messager) {
      this.messager = messager;
    }
  
    /** Emits a global warning that doesn't target a particular element. */
    public void warn(String template, Object... arguments) {
      messager.printMessage(Diagnostic.Kind.WARNING, String.format(template, arguments));
    }
  
    /** Emits a warning for a specific element. */
    public void warn(Element element, String template, Object... arguments) {
      message(Diagnostic.Kind.WARNING, element, template, arguments);
    }
  
    /** Emits an error for a specific element. */
    public void error(Element element, String template, Object... arguments) {
      message(Diagnostic.Kind.ERROR, element, template, arguments);
    }
  
    private void message(
        Diagnostic.Kind level, Element element, String template, Object[] arguments) {
      if (emittedMessages.add(new MessageId(level, element, template, arguments))) {
        messager.printMessage(
            level, formatLocation(element) + String.format(template, arguments), element);
      }
    }
  
    private static String formatLocation(Element element) {
      switch (element.getKind()) {
        case CLASS:
        case INTERFACE:
          return String.format("[%s] ", element.getSimpleName());
        case FIELD:
        case METHOD:
        case CONSTRUCTOR:
          return String.format(
              "[%s.%s] ", element.getEnclosingElement().getSimpleName(), element.getSimpleName());
        case PARAMETER:
          Element method = element.getEnclosingElement();
          Element type = method.getEnclosingElement();
          return String.format(
              "[%s.%s, parameter %s] ",
              type.getSimpleName(), method.getSimpleName(), element.getSimpleName());
        default:
          // We don't emit messages for other types of elements in the mapper processor. Handle
          // gracefully nevertheless:
          return String.format("[%s] ", element);
      }
    }
  
    private static class MessageId {
  
      private final Diagnostic.Kind level;
      private final Element element;
      private final String template;
      private final Object[] arguments;
  
      private MessageId(Diagnostic.Kind level, Element element, String template, Object[] arguments) {
        this.level = level;
        this.element = element;
        this.template = template;
        this.arguments = arguments;
      }
  
      @Override
      public boolean equals(Object other) {
        if (other == this) {
          return true;
        } else if (other instanceof MessageId) {
          MessageId that = (MessageId) other;
          return this.level == that.level
              && Objects.equals(this.element, that.element)
              && Objects.equals(this.template, that.template)
              && Arrays.deepEquals(this.arguments, that.arguments);
        } else {
          return false;
        }
      }
  
      @Override
      public int hashCode() {
        return Objects.hash(level, element, template, Arrays.hashCode(arguments));
      }
    }
  }
  