/**
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */
package org.exolab.castor.xml.schema;

import java.math.BigDecimal;
import java.util.Enumeration;

import org.exolab.castor.xml.ValidationException;

/**
 * Represents the base type for XML Schema Facets
 * 
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2005-12-13 14:58:48 -0700 (Tue, 13 Dec 2005) $
 **/
public class Facet extends Annotated {
  /** SerialVersionUID */
  private static final long serialVersionUID = 7821829275720939922L;

  public static final String ENUMERATION = "enumeration";
  public static final String LENGTH = "length";
  public static final String PATTERN = "pattern";
  public static final String PRECISION = "precision";
  public static final String MAX_EXCLUSIVE = "maxExclusive";
  public static final String MAX_INCLUSIVE = "maxInclusive";
  public static final String MIN_EXCLUSIVE = "minExclusive";
  public static final String MIN_INCLUSIVE = "minInclusive";
  public static final String MAX_LENGTH = "maxLength";
  public static final String MIN_LENGTH = "minLength";
  public static final String WHITESPACE = "whiteSpace";
  public static final String TOTALDIGITS = "totalDigits";
  public static final String FRACTIONDIGITS = "fractionDigits";

  public static final String WHITESPACE_PRESERVE = "preserve";
  public static final String WHITESPACE_REPLACE = "replace";
  public static final String WHITESPACE_COLLAPSE = "collapse";

  private static final String CLASSNAME = Facet.class.getName();

  private static final String NULL_ARGUMENT = "A null argument was passed to " + CLASSNAME + "#";

  private static final String ZERO_LENGTH_STRING =
      "A zero-length String was passed to " + CLASSNAME + "#";

  /** The name of this Facet. */
  private final String _name;
  /** The character value of this Facet. */
  private final String _value;

  /**
   * The owning {@link SimpleType} instance.
   */
  private SimpleType _owningType;

  /**
   * Creates a new Facet with the given name.
   * 
   * @param name the name of the Facet
   * @param value the value of the Facet
   **/
  public Facet(final String name, final String value) {
    if (name == null) {
      String err = NULL_ARGUMENT;
      err += "Facet: 'name' and 'value' must not be null.";
      throw new IllegalArgumentException(err);
    }
    if (name.length() == 0) {
      String err = ZERO_LENGTH_STRING;
      err += "Facet: 'name' and 'value' must not be zero-length.";
      throw new IllegalArgumentException(err);
    }
    this._name = name;
    this._value = value;
  }

  /**
   * Returns the name of this Facet.
   * 
   * @return the name of this Facet
   **/
  public String getName() {
    return _name;
  }

  /**
   * Returns the character (String) representation of this facet.
   * 
   * @return the value of this facet
   **/
  public String getValue() {
    return this._value;
  } // -- getValue

  /**
   * Returns true if this Facet can occur more than once, such as the "enumeration" facet.
   * 
   * @return true if this Facet can occur more than once.
   **/
  public boolean isMultivalued() {
    return _name.equals(Facet.ENUMERATION) || _name.equals(Facet.PATTERN);
  }

  /**
   * Returns an int representation of the value of this facet.
   * 
   * @return an int representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a int.
   **/
  public int toInt() throws NumberFormatException {
    return Integer.parseInt(_value);
  }

  /**
   * Returns a long representation of the value of this facet.
   * 
   * @return a long representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a long.
   **/
  public long toLong() throws NumberFormatException {
    return Long.parseLong(_value);
  }

  /**
   * Returns an short representation of the value of this facet.
   * 
   * @return an short representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a short.
   **/
  public short toShort() throws NumberFormatException {
    return Short.parseShort(_value);
  }

  /**
   * Returns a double representation of the value of this facet.
   * 
   * @return a double representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a float.
   */
  public float toFloat() throws NumberFormatException {
    if (_value.equals("INF")) {
      return Float.POSITIVE_INFINITY;
    }
    if (_value.equals("-INF")) {
      return Float.NEGATIVE_INFINITY;
    }
    return Float.valueOf(_value).floatValue();
  }

  /**
   * Returns a double representation of the value of this facet.
   * 
   * @return a double representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a double.
   **/
  public double toDouble() throws NumberFormatException {
    return Double.parseDouble(_value);
  }

  /**
   * Returns a byte representation of the value of this facet.
   * 
   * @return a byte representation of the value of this facet
   * @throws NumberFormatException if the value fails to parse as a byte.
   **/
  public byte toByte() throws NumberFormatException {
    return Byte.parseByte(_value);
  }

  /**
   * Returns a {@link BigDecimal} representation of the value of this facet.
   * 
   * @return a {@link BigDecimal} representation of the value of this facet
   * @throws NumberFormatException if the value cannot be parsed as number
   */
  public BigDecimal toBigDecimal() throws NumberFormatException {
    return new BigDecimal(_value);
  }

  /**
   * Returns the type of this Schema Structure.
   * 
   * @return the type of this Schema Structure
   **/
  public short getStructureType() {
    return Structure.FACET;
  }

  /**
   * Checks the validity of this Schema defintion.
   * 
   * @exception ValidationException when this Schema definition is invalid.
   **/
  public void validate() throws ValidationException {
    // TODO: shouldn't this be converted to an abstract method ?
    // -- do nothing for now
  }

  /**
   * Checks whether the current facet overrides a facet of the base data type. This does generally
   * happen when a data type is derived by restriction and it therefore has facet(s), which are more
   * restrictive than the ones of the base data type.
   *
   * <p>
   * This method is used for merging facets of the base and derived types, in order to create an
   * effective set of facets for the derived type.
   *
   * <p>
   * It's important to note that this method does not perform any validity checks. Validation must
   * be generally performed <b>before</b> trying to merge facets of the base and derived types.
   *
   * @param baseFacet a facet of the base data type
   * @return <code>true</code>, if the current facet overrides <code>baseFacet</code>;
   *         <code>false</code>, otherwise.
   * 
   * @see #checkConstraints(Enumeration,Enumeration)
   * @see SimpleType#getEffectiveFacets()
   */
  public boolean overridesBase(final Facet baseFacet) {
    return getName().equals(baseFacet.getName());
  }

  /**
   * Checks the constraints on the current facet against the other local facets of the same derived
   * data type and facets of the base data type. Validation is performed according to the rules
   * defined in "<a href="http://www.w3.org/TR/xmlschema-2/">XML Schema Part 2: Datatypes Second
   * Edition</a>" document.
   *
   * @param localFacets local facets of the data type
   * @param baseFacets merged facets of the base data type
   * @throws SchemaException when the current facet does not satisfy schema component validation
   *         constraints
   */
  public void checkConstraints(final Enumeration localFacets, final Enumeration baseFacets)
      throws SchemaException {
    // Does nothing by default
  }

  /**
   * Sets the owning {@link SimpleType} instance.
   * 
   * @param owningType The owning {@link SimpleType} instance.
   */
  public void setOwningType(final SimpleType owningType) {
    _owningType = owningType;
  }

  /**
   * Returns the owning {@link SimpleType} instance.
   * 
   * @return The owning {@link SimpleType} instance.
   */
  public SimpleType getOwningType() {
    return _owningType;
  }

} // -- Facet
