/*
 * Copyright 2006-2007 Keith Visco, Edward Kuns
 * 
 * Licensed 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 org.exolab.castor.builder.types;

import java.util.LinkedList;
import java.util.List;

import org.exolab.castor.xml.schema.Facet;
import org.exolab.javasource.JSourceCode;

/**
 * A base class for types which support the pattern facet.
 * 
 * @author <a href="mailto:keith AT kvisco DOT com">Keith Visco</a>
 * @author <a href="mailto:edward DOT kuns AT aspect DOT com">Edward Kuns</a>
 * @version $Revision: 6678 $ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $
 * @since 1.1
 */
public abstract class AbstractPatternFacet extends XSType {
  // --------------------------------------------------------------------------

  /** The list of pattern facets. */
  private List<String> _patterns = new LinkedList<String>();

  // --------------------------------------------------------------------------

  /**
   * Adds a pattern branch for this XSType. To successfully pass the pattern facets, only one branch
   * needs to pass.
   * 
   * @param pattern The regular expression for this XSType.
   */
  public final void addPattern(final String pattern) {
    _patterns.add(pattern);
  }

  /**
   * Get list of pattern facets.
   * 
   * @return List of pattern facets.
   */
  public final List<String> getPatterns() {
    return _patterns;
  }

  // --------------------------------------------------------------------------

  /**
   * {@inheritDoc}
   */
  protected void setFacet(final Facet facet) {
    addPatternFacet(facet);
  }

  /**
   * Transfer given facet if it is a pattern.
   *
   * @param facet The facet to transfer.
   */
  protected final void addPatternFacet(final Facet facet) {
    if (Facet.PATTERN.equals(facet.getName())) {
      addPattern(facet.getValue());
    }
  }

  /**
   * Generate the source code for pattern facet validation.
   *
   * @param jsc The JSourceCode to fill in.
   * @param validatorName The name of the TypeValidator that the patterns should be added to.
   */
  protected final void codePatternFacet(final JSourceCode jsc, final String validatorName) {
    for (String pattern : _patterns) {
      jsc.add("{0}.addPattern(\"{1}\");", validatorName, escapePattern(pattern));
    }
  }

  /**
   * Escapes special characters in the given String so that it can be printed correctly.
   *
   * @param str The String to escape.
   * @return The escaped String, or null if the given String was null.
   */
  private static String escapePattern(final String str) {
    if (str == null) {
      return str;
    }

    // -- make sure we have characters to escape
    if (str.indexOf('\\') < 0 && str.indexOf('\"') < 0) {
      return str;
    }

    StringBuilder sb = new StringBuilder();

    char[] chars = str.toCharArray();
    for (char ch : chars) {
      if (ch == '\\') {
        sb.append(ch);
      }
      if (ch == '\"') {
        sb.append('\\');
      }
      sb.append(ch);
    }

    return sb.toString();
  }

  // --------------------------------------------------------------------------
}
