/*
 * This work is Open Source and licensed by the European Commission under the
 * conditions of the European Public License v1.1 
 *  
 * (http://www.osor.eu/eupl/european-union-public-licence-eupl-v.1.1); 
 * 
 * any use of this file implies acceptance of the conditions of this license. 
 * 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 eu.stork.peps.auth.commons;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.commons.lang.StringUtils;

/**
 * This class holds static helper methods.
 * 
 * @author ricardo.ferreira@multicert.com, renato.portela@multicert.com,
 *         luis.felix@multicert.com, hugo.magalhaes@multicert.com,
 *         paulo.ribeiro@multicert.com
 * @version $Revision: 1.5 $, $Date: 2010-12-15 23:19:59 $
 */
public final class AttributeUtil {
  
  /**
   * Private constructor. Prevents the class from being instantiated.
   */
  private AttributeUtil() {
    // empty constructor
  }
  
  /**
   * Safe escape any given string.
   * 
   * @param value The HTTP Value to escaped.
   * 
   * @return The value escaped value.
   */
  public static String escape(final String value) {
    
    final String attrSep = PEPSValues.ATTRIBUTE_SEP.toString();
    final String attrTupleSep = PEPSValues.ATTRIBUTE_TUPLE_SEP.toString();
    final String attrValueSep = PEPSValues.ATTRIBUTE_VALUE_SEP.toString();
    
    final String escAttrSep = "%" + (int) attrSep.charAt(0);
    final String escAttrTupleSep = "%" + (int) attrTupleSep.charAt(0);
    final String escAttrValueSep = "%" + (int) attrValueSep.charAt(0);
    
    return value.replace(attrSep, escAttrSep)
      .replace(attrTupleSep, escAttrTupleSep)
      .replace(attrValueSep, escAttrValueSep);
  }
  
  /**
   * Unescape any given string.
   * 
   * @param value The HTTP Value to be unescaped.
   * 
   * @return The value unescaped value.
   */
  public static String unescape(final String value) {
    final String attrSep = PEPSValues.ATTRIBUTE_SEP.toString();
    final String attrTupleSep = PEPSValues.ATTRIBUTE_TUPLE_SEP.toString();
    final String attrValueSep = PEPSValues.ATTRIBUTE_VALUE_SEP.toString();
    
    final String escAttrSep = "%" + (int) attrSep.charAt(0);
    final String escAttrTupleSep = "%" + (int) attrTupleSep.charAt(0);
    final String escAttrValueSep = "%" + (int) attrValueSep.charAt(0);
    
    return value.replace(escAttrSep, attrSep)
      .replace(escAttrTupleSep, attrTupleSep)
      .replace(escAttrValueSep, attrValueSep);
  }
  
  /**
   * Appends the string representation of an object to a StringBuilder.
   * 
   * @param strBuilder The StringBuilder to append to.
   * @param val The string representation of an object.
   */
  public static void appendIfNotNull(final StringBuilder strBuilder,
    final Object val) {
    
    if (val != null) {
      strBuilder.append(val);
    }
  }
  
  /**
   * Given a separator and a list of strings, joins the list, as a string,
   * separated by the separator string.
   * 
   * @param list The list of strings to join.
   * @param separator The separator string.
   * @return the list, as a string, separated by the separator string.
   */
  public static String listToString(final List<String> list,
    final String separator) {
    
    final StringBuilder strBuilder = new StringBuilder();
    for (final String s : list) {
      if (!StringUtils.isEmpty(s)) {
        strBuilder.append(AttributeUtil.escape(s) + separator);
      }
    }
    return strBuilder.toString();
  }
  
  /**
   * Given a separator and a map of strings to strings, joins the map, as a
   * string, separated by the separator string with the pair key/value
   * concatenated with a '='.
   * 
   * @param map The map of strings to join.
   * @param separator The separator string.
   * 
   * @return the map of strings, as a string, separated by the separator string
   *         with the pair key/value concatenated with a '='.
   */
  public static String mapToString(final Map<String, String> map,
    final String separator) {
    
    final StringBuilder strBuilder = new StringBuilder();
    final Iterator<Entry<String, String>> valuesIt = map.entrySet().iterator();
    while (valuesIt.hasNext()) {
      final Entry<String, String> entry = valuesIt.next();
      strBuilder.append(entry.getKey());
      strBuilder.append('=');
      strBuilder.append(AttributeUtil.escape(entry.getValue()));
      strBuilder.append(separator);
    }
    return strBuilder.toString();
  }
  
  /**
   * Validates the attribute value format.
   * 
   * @param value The attribute value to validate.
   * 
   * @return true if value has a valid format.
   */
  public static boolean isValidValue(final String value) {
    boolean retVal = false;
    if (value != null && value.charAt(0) == '[' && value.endsWith("]")) {
      final String tmpAttrValue = value.substring(1, value.length() - 1);
      final String[] vals =
        tmpAttrValue.split(PEPSValues.ATTRIBUTE_VALUE_SEP.toString());
      
      if (tmpAttrValue.length() >= 0
        || (vals.length > 0 && vals[0].length() > 0)) {
        retVal = true;
      }
    }
    return retVal;
  }
  
  /**
   * Validates the attribute type value. It's case insensitive. E.g. return true
   * value to: a) "true", "TRUE", "True", ... b) "false", "FALSE", "False", ...
   * 
   * @param type The attribute type value.
   * 
   * @return true if type has a true or false (case insensitive) value.
   */
  public static boolean isValidType(final String type) {
      return StringUtils.isNotEmpty(type) && (PEPSValues.TRUE.toString().equalsIgnoreCase(type) || PEPSValues.FALSE.toString().equalsIgnoreCase(type)) ;
  }
  
  /**
   * Validates the Personal attribute tuple. E.g. name:type:[value]:status
   * 
   * @param tuples The Personal attribute's tuple.
   * 
   * @return true if the tuples' format is valid.
   * 
   * @see PEPSUtil#validateParameter(String, String, String)
   * @see String#equalsIgnoreCase(String)
   */
  public static boolean hasValidTuples(final String[] tuples) {
    boolean retVal = false;

      final int numberTuples = AttributeConstants.NUMBER_TUPLES.intValue();
      if (tuples != null && tuples.length == numberTuples) {
      // validate attrName
      final int attrNameIndex = AttributeConstants.ATTR_NAME_INDEX.intValue();
      final int attrTypeIndex = AttributeConstants.ATTR_TYPE_INDEX.intValue();
      final int attrValueIndex = AttributeConstants.ATTR_VALUE_INDEX.intValue();
      
      retVal =
        StringUtils.isNotEmpty(tuples[attrNameIndex])
          && StringUtils.isNotEmpty(tuples[attrTypeIndex])
          && StringUtils.isNotEmpty(tuples[attrValueIndex])
          && AttributeUtil.isValidType(tuples[attrTypeIndex])
          && AttributeUtil.isValidValue(tuples[attrValueIndex]);
    }
    return retVal;
  }
  
  /**
   * Check if all mandatory attributes have values.
   * 
   * @param personalAttrList The Personal Attributes List.
   * 
   * @return true if all mandatory attributes have values, false if at least one
   *         attribute doesn't have value.
   */
  public static boolean checkMandatoryAttributes(
    final IPersonalAttributeList personalAttrList) {
    
    final Iterator<PersonalAttribute> itAttributes =
      personalAttrList.values().iterator();
    boolean retVal = true;
    while (itAttributes.hasNext() && retVal) {
      final PersonalAttribute attr = itAttributes.next();
      if (attr.isRequired()
        && !STORKStatusCode.STATUS_AVAILABLE.toString()
          .equals(attr.getStatus())) {
        retVal = false;
      }
    }
    return retVal;
  }
}