/**
    * Copyright 2005-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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 org.kuali.rice.krad.datadictionary.validation;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.datetime.DateTimeService;
  import org.kuali.rice.core.api.uif.DataType;
  import org.kuali.rice.krad.datadictionary.exception.AttributeValidationException;
  import org.kuali.rice.krad.uif.UifConstants;
  
  import java.math.BigDecimal;
  import java.text.ParseException;
  import java.util.Collection;
  import java.util.Date;
  
  /**
   * ValidationUtils provides static utility methods for validation processing
   *
   * <p>Inherited from Kuali Student and adapted extensively</p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ValidationUtils {
  
      /**
       * constructs a path by appending the attribute name to the provided path
       *
       * @param attributePath - a string representation of specifically which attribute (at some depth) is being accessed
       * @param attributeName - the attribute name
       * @return the path
       */
      public static String buildPath(String attributePath, String attributeName) {
          if (StringUtils.isNotBlank(attributeName)) {
              if (StringUtils.isNotBlank(attributePath)) {
                  return new StringBuilder(attributePath).append(".").append(attributeName).toString();
              }
  
              return attributeName;
          }
          return attributePath;
      }
  
      /**
       * Used to get the rightmost index value of an attribute path.
       *
       * @param attributePath
       * @return the right index of value of attribute path, -1 if path has no index
       */
      public static int getLastPathIndex(String attributePath) {
          int index = -1;
  
          int leftBracket = attributePath.lastIndexOf("[");
          int rightBracket = attributePath.lastIndexOf("]");
  
          if (leftBracket > 0 && rightBracket > leftBracket) {
              String indexString = attributePath.substring(leftBracket + 1, rightBracket);
              try {
                  index = Integer.valueOf(indexString).intValue();
              } catch (NumberFormatException e) {
                  // Will just return -1
              }
          }
  
          return index;
      }
  
      /**
       * compares the value provided by the user and the one specified by the {@code WhenConstraint}
       *
       * @param fieldValue - the value found in the field specified by a {@code CaseConstraint}'s {@code propertyName}
       * @param whenValue - the value specified by a {@code WhenConstraint}
       * @param dataType - the data type of the field which caseConstraint's propertyName refers to
       * @param operator - the relationship to check between the {@code fieldValue} and the {@code whenValue}
       * @param isCaseSensitive - whether string comparison will be carried out in a case sensitive fashion
       * @param dateTimeService - used to convert strings to dates
       * @return
       */
      public static boolean compareValues(Object fieldValue, Object whenValue, DataType dataType, String operator,
              boolean isCaseSensitive, DateTimeService dateTimeService) {
  
          boolean result = false;
          Integer compareResult = null;
  
          if (UifConstants.CaseConstraintOperators.HAS_VALUE.equalsIgnoreCase(operator)) {
              if (fieldValue == null) {
                  return "false".equals(whenValue.toString().toLowerCase());
             }
             if (fieldValue instanceof String && ((String) fieldValue).isEmpty()) {
                 return "false".equals(whenValue.toString().toLowerCase());
             }
             if (fieldValue instanceof Collection && ((Collection<?>) fieldValue).isEmpty()) {
                 return "false".equals(whenValue.toString().toLowerCase());
             }
             return "true".equals(whenValue.toString().toLowerCase());
         }
         // Convert objects into appropriate data types
         if (null != dataType) {
             if (DataType.STRING.equals(dataType)) {
                 String v1 = getString(fieldValue);
                 String v2 = getString(whenValue);
 
                 if (!isCaseSensitive) {
                     v1 = v1.toUpperCase();
                     v2 = v2.toUpperCase();
                 }
 
                 compareResult = v1.compareTo(v2);
             } else if (DataType.INTEGER.equals(dataType)) {
                 Integer v1 = getInteger(fieldValue);
                 Integer v2 = getInteger(whenValue);
                 compareResult = v1.compareTo(v2);
             } else if (DataType.LONG.equals(dataType)) {
                 Long v1 = getLong(fieldValue);
                 Long v2 = getLong(whenValue);
                 compareResult = v1.compareTo(v2);
             } else if (DataType.DOUBLE.equals(dataType)) {
                 Double v1 = getDouble(fieldValue);
                 Double v2 = getDouble(whenValue);
                 compareResult = v1.compareTo(v2);
             } else if (DataType.FLOAT.equals(dataType)) {
                 Float v1 = getFloat(fieldValue);
                 Float v2 = getFloat(whenValue);
                 compareResult = v1.compareTo(v2);
             } else if (DataType.BOOLEAN.equals(dataType)) {
                 Boolean v1 = getBoolean(fieldValue);
                 Boolean v2 = getBoolean(whenValue);
                 compareResult = v1.compareTo(v2);
             } else if (DataType.DATE.equals(dataType)) {
                 Date v1 = getDate(fieldValue, dateTimeService);
                 Date v2 = getDate(whenValue, dateTimeService);
                 compareResult = v1.compareTo(v2);
             }
         }
 
         if (null != compareResult) {
             if ((UifConstants.CaseConstraintOperators.EQUALS.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.GREATER_THAN_EQUAL.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.LESS_THAN_EQUAL.equalsIgnoreCase(operator)) && 0 == compareResult) {
                 result = true;
             }
 
             if ((UifConstants.CaseConstraintOperators.NOT_EQUAL.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.NOT_EQUALS.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.GREATER_THAN.equalsIgnoreCase(operator)) && compareResult >= 1) {
                 result = true;
             }
 
             if ((UifConstants.CaseConstraintOperators.NOT_EQUAL.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.NOT_EQUALS.equalsIgnoreCase(operator) || UifConstants
                     .CaseConstraintOperators.LESS_THAN.equalsIgnoreCase(operator)) && compareResult <= -1) {
                 result = true;
             }
         }
 
         return result;
     }
 
     /**
      * converts the provided object into an integer
      *
      * @param o - the object to convert
      * @return the integer value
      */
     public static Integer getInteger(Object o) {
         Integer result = null;
         if (o instanceof Integer) {
             return (Integer) o;
         }
         if (o == null) {
             return null;
         }
         if (o instanceof Number) {
             return ((Number) o).intValue();
         }
         String s = o.toString();
         if (s != null && s.trim().length() > 0) {
             result = Integer.valueOf(s.trim());
         }
         return result;
     }
 
     /**
      * converts the provided object into a long
      *
      * @param o - the object to convert
      * @return the long value
      */
     public static Long getLong(Object o) {
         Long result = null;
         if (o instanceof Long) {
             return (Long) o;
         }
         if (o == null) {
             return null;
         }
         if (o instanceof Number) {
             return ((Number) o).longValue();
         }
         String s = o.toString();
         if (s != null && s.trim().length() > 0) {
             result = Long.valueOf(s.trim());
         }
         return result;
     }
 
     /**
      * converts the provided object into an float
      *
      * @param o - the object to convert
      * @return the float value
      */
     public static Float getFloat(Object o) {
         Float result = null;
         if (o instanceof Float) {
             return (Float) o;
         }
         if (o == null) {
             return null;
         }
         if (o instanceof Number) {
             return ((Number) o).floatValue();
         }
         String s = o.toString();
         if (s != null && s.trim().length() > 0) {
             result = Float.valueOf(s.trim());
         }
         return result;
     }
 
     /**
      * converts the provided object into a double
      *
      * @param o - the object to convert
      * @return the double value
      */
     public static Double getDouble(Object o) {
         Double result = null;
         if (o instanceof BigDecimal) {
             return ((BigDecimal) o).doubleValue();
         }
         if (o instanceof Double) {
             return (Double) o;
         }
         if (o == null) {
             return null;
         }
         if (o instanceof Number) {
             return ((Number) o).doubleValue();
         }
         String s = o.toString();
         if (s != null && s.trim().length() > 0) {
             result = Double.valueOf(s.trim());
         }
         return result;
     }
 
     /**
      * determines whether the provided object is a date and tries to converts non-date values
      *
      * @param object - the object to convert/cast into a date
      * @param dateTimeService - used to convert strings to dates
      * @return a date object
      * @throws IllegalArgumentException
      */
     public static Date getDate(Object object, DateTimeService dateTimeService) throws IllegalArgumentException {
         Date result = null;
         if (object instanceof Date) {
             return (Date) object;
         }
         if (object == null) {
             return null;
         }
         String s = object.toString();
         if (s != null && s.trim().length() > 0) {
             try {
                 result = dateTimeService.convertToDate(s.trim());
             } catch (ParseException e) {
                 throw new IllegalArgumentException(e);
             }
         }
         return result;
     }
 
     /**
      * converts the provided object into a string
      *
      * @param o - the object to convert
      * @return the string value
      */
     public static String getString(Object o) {
         if (o instanceof String) {
             return (String) o;
         }
         if (o == null) {
             return null;
         }
         return o.toString();
     }
 
     /**
      * converts the provided object into a boolean
      *
      * @param o - the object to convert
      * @return the boolean value
      */
     public static Boolean getBoolean(Object o) {
         Boolean result = null;
         if (o instanceof Boolean) {
             return (Boolean) o;
         }
         if (o == null) {
             return null;
         }
         String s = o.toString();
         if (s != null && s.trim().length() > 0) {
             result = Boolean.parseBoolean(s.trim());
         }
         return result;
     }
 
     /**
      * checks whether the string contains non-whitespace characters
      *
      * @param string
      * @return true if the string contains at least one none-whitespace character, false otherwise
      */
     public static boolean hasText(String string) {
 
         if (string == null || string.length() < 1) {
             return false;
         }
         int stringLength = string.length();
 
         for (int i = 0; i < stringLength; i++) {
             char currentChar = string.charAt(i);
             if (' ' != currentChar || '\t' != currentChar || '\n' != currentChar) {
                 return true;
             }
         }
 
         return false;
     }
 
     /**
      * checks whether the provided object is null or empty
      *
      * @param value - the object to check
      * @return true if the object is null or empty, false otherwise
      */
     public static boolean isNullOrEmpty(Object value) {
         return value == null || (value instanceof String && StringUtils.isBlank(((String) value).trim()));
     }
 
     /**
      * defines possible result values of a comparison operation
      */
     public static enum Result {
         VALID, INVALID, UNDEFINED
     }
 
     ;
 
     /**
      * attempts to convert the provided value to the given dataType
      *
      * @param value - the object to convert
      * @param dataType - the data type to convert into
      * @param dateTimeService - used to convert strings to dates
      * @return the converted value if null or successful, otherwise throws an exception
      * @throws AttributeValidationException
      */
     public static Object convertToDataType(Object value, DataType dataType,
             DateTimeService dateTimeService) throws AttributeValidationException {
         Object returnValue = value;
 
         if (null == value) {
             return null;
         }
 
         switch (dataType) {
             case BOOLEAN:
                 if (!(value instanceof Boolean)) {
                     returnValue = Boolean.valueOf(value.toString());
 
                     // Since the Boolean.valueOf is exceptionally loose - it basically takes any string and makes it false
                     if (!value.toString().equalsIgnoreCase("TRUE") && !value.toString().equalsIgnoreCase("FALSE")) {
                         throw new AttributeValidationException("Value " + value.toString() + " is not a boolean!");
                     }
                 }
                 break;
             case INTEGER:
                 if (!(value instanceof Number)) {
                     returnValue = Integer.valueOf(value.toString());
                 }
                 break;
             case LONG:
                 if (!(value instanceof Number)) {
                     returnValue = Long.valueOf(value.toString());
                 }
                 break;
             case DOUBLE:
                 if (!(value instanceof Number)) {
                     returnValue = Double.valueOf(value.toString());
                 }
                 if (((Double) returnValue).isNaN()) {
                     throw new AttributeValidationException("Infinite Double values are not valid!");
                 }
                 if (((Double) returnValue).isInfinite()) {
                     throw new AttributeValidationException("Infinite Double values are not valid!");
                 }
                 break;
             case FLOAT:
                 if (!(value instanceof Number)) {
                     returnValue = Float.valueOf(value.toString());
                 }
                 if (((Float) returnValue).isNaN()) {
                     throw new AttributeValidationException("NaN Float values are not valid!");
                 }
                 if (((Float) returnValue).isInfinite()) {
                     throw new AttributeValidationException("Infinite Float values are not valid!");
                 }
                 break;
             case TRUNCATED_DATE:
             case DATE:
                 if (!(value instanceof Date)) {
                     try {
                         returnValue = dateTimeService.convertToDate(value.toString());
                     } catch (ParseException pe) {
                         throw new AttributeValidationException("Value " + value.toString() + " is not a date!");
                     }
                 }
                 break;
             case STRING:
         }
 
         return returnValue;
     }
 
     /**
      * checks whether the provided value is greater than the limit given
      *
      * @param value - the object to check
      * @param limit - the limit to use
      * @param <T>
      * @return one of the values in {@link  Result}
      */
     public static <T> Result isGreaterThan(T value, Comparable<T> limit) {
         return limit == null ? Result.UNDEFINED : (limit.compareTo(value) < 0 ? Result.VALID : Result.INVALID);
     }
 
     /**
      * checks whether the provided value is greater than or equal to the limit given
      *
      * @param value - the object to check
      * @param limit - the limit to use
      * @param <T>
      * @return one of the values in {@link  Result}
      */
     public static <T> Result isGreaterThanOrEqual(T value, Comparable<T> limit) {
         return limit == null ? Result.UNDEFINED : (limit.compareTo(value) <= 0 ? Result.VALID : Result.INVALID);
     }
 
     /**
      * checks whether the provided value is less than the limit given
      *
      * @param value - the object to check
      * @param limit - the limit to use
      * @param <T>
      * @return one of the values in {@link  Result}
      */
     public static <T> Result isLessThan(T value, Comparable<T> limit) {
         return limit == null ? Result.UNDEFINED : (limit.compareTo(value) > 0 ? Result.VALID : Result.INVALID);
     }
 
     /**
      * checks whether the provided value is greater than the limit given
      *
      * @param value - the object to check
      * @param limit - the limit to use
      * @param <T>
      * @return one of the values in {@link  Result}
      */
     public static <T> Result isLessThanOrEqual(T value, Comparable<T> limit) {
         return limit == null ? Result.UNDEFINED : (limit.compareTo(value) >= 0 ? Result.VALID : Result.INVALID);
     }
 
     /**
      * converts a path into an array of its path components
      *
      * @param fieldPath - a string representation of specifically which attribute (at some depth) is being accessed
      * @return the array of path components
      */
     public static String[] getPathTokens(String fieldPath) {
         return (fieldPath != null && fieldPath.contains(".") ? fieldPath.split("\\.") : new String[]{fieldPath});
     }
 
 }