/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.config.spring.parsers.processors;

import org.mule.runtime.config.spring.parsers.PreProcessor;
import org.mule.runtime.config.spring.parsers.assembly.configuration.PropertyConfiguration;
import org.mule.runtime.config.spring.util.SpringXMLUtils;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;

/**
 * Throws an exception if any of the required attributes (after translation) are missing. Designed to cooperates with
 * {@link org.mule.runtime.config.spring.parsers.delegate.AbstractSerialDelegatingDefinitionParser#addHandledException(Class)}
 */
public class RequireAttribute implements PreProcessor {

  private Set required;

  public RequireAttribute(String required) {
    this(new String[] {required});
  }

  public RequireAttribute(String[] required) {
    this.required = new HashSet(Arrays.asList(required));
  }

  public void preProcess(PropertyConfiguration config, Element element) {
    NamedNodeMap attributes = element.getAttributes();
    Iterator names = required.iterator();
    while (names.hasNext()) {
      String name = (String) names.next();
      boolean found = false;
      for (int i = 0; i < attributes.getLength() && !found; i++) {
        String alias = SpringXMLUtils.attributeName((Attr) attributes.item(i));
        // don't translate to alias because the error message is in terms of the attributes
        // the user enters - we don't want to expose the details of translations
        // found = name.equals(config.translateName(alias));
        found = name.equals(alias);
      }
      if (!found) {
        throw new RequireAttributeException("Attribute " + name + " is required here.");
      }
    }
  }

  public static class RequireAttributeException extends IllegalStateException {

    public RequireAttributeException(String message) {
      super(message);
    }

  }

}