/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2009 Sun Microsystems, Inc.
 */

package org.opends.sdk.schema;



import static com.sun.opends.sdk.messages.Messages.*;
import static org.opends.sdk.schema.SchemaConstants.*;

import java.util.HashSet;

import org.opends.sdk.ByteSequence;
import org.opends.sdk.LocalizableMessageBuilder;




/**
 * This class implements the teletex terminal identifier attribute
 * syntax, which contains a printable string (the terminal identifier)
 * followed by zero or more parameters, which start with a dollar sign
 * and are followed by a parameter name, a colon, and a value. The
 * parameter value should consist of any string of bytes (the dollar
 * sign and backslash must be escaped with a preceding backslash), and
 * the parameter name must be one of the following strings:
 * <UL>
 * <LI>graphic</LI>
 * <LI>control</LI>
 * <LI>misc</LI>
 * <LI>page</LI>
 * <LI>private</LI>
 * </UL>
 */
final class TeletexTerminalIdentifierSyntaxImpl extends
    AbstractSyntaxImpl
{
  /**
   * The set of allowed fax parameter values, formatted entirely in
   * lowercase characters.
   */
  private static final HashSet<String> ALLOWED_TTX_PARAMETERS =
      new HashSet<String>(5);

  static
  {
    ALLOWED_TTX_PARAMETERS.add("graphic");
    ALLOWED_TTX_PARAMETERS.add("control");
    ALLOWED_TTX_PARAMETERS.add("misc");
    ALLOWED_TTX_PARAMETERS.add("page");
    ALLOWED_TTX_PARAMETERS.add("private");
  }



  @Override
  public String getEqualityMatchingRule()
  {
    return EMR_CASE_IGNORE_OID;
  }



  public String getName()
  {
    return SYNTAX_TELETEX_TERM_ID_NAME;
  }



  @Override
  public String getOrderingMatchingRule()
  {
    return OMR_CASE_IGNORE_OID;
  }



  @Override
  public String getSubstringMatchingRule()
  {
    return SMR_CASE_IGNORE_OID;
  }



  public boolean isHumanReadable()
  {
    return false;
  }



  /**
   * Indicates whether the provided value is acceptable for use in an
   * attribute with this syntax. If it is not, then the reason may be
   * appended to the provided buffer.
   * 
   * @param schema
   *          The schema in which this syntax is defined.
   * @param value
   *          The value for which to make the determination.
   * @param invalidReason
   *          The buffer to which the invalid reason should be appended.
   * @return <CODE>true</CODE> if the provided value is acceptable for
   *         use with this syntax, or <CODE>false</CODE> if not.
   */
  public boolean valueIsAcceptable(Schema schema, ByteSequence value,
      LocalizableMessageBuilder invalidReason)
  {
    // Get a lowercase string representation of the value and find its
    // length.
    final String valueString = value.toString();
    final int valueLength = valueString.length();

    // The value must contain at least one character.
    if (valueLength == 0)
    {

      invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_EMPTY.get());
      return false;
    }

    // The first character must be a printable string character.
    char c = valueString.charAt(0);
    if (!PrintableStringSyntaxImpl.isPrintableCharacter(c))
    {

      invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_NOT_PRINTABLE.get(
          valueString, String.valueOf(c), 0));
      return false;
    }

    // Continue reading until we find a dollar sign or the end of the
    // string. Every intermediate character must be a printable string
    // character.
    int pos = 1;
    for (; pos < valueLength; pos++)
    {
      c = valueString.charAt(pos);
      if (c == '$')
      {
        pos++;
        break;
      }
      else
      {
        if (!PrintableStringSyntaxImpl.isPrintableCharacter(c))
        {

          invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_NOT_PRINTABLE
              .get(valueString, String.valueOf(c), pos));
        }
      }
    }

    if (pos >= valueLength)
    {
      // We're at the end of the value, so it must be valid unless the
      // last character was a dollar sign.
      if (c == '$')
      {

        invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_END_WITH_DOLLAR
            .get(valueString));
        return false;
      }
      else
      {
        return true;
      }
    }

    // Continue reading until we find the end of the string. Each
    // substring must be a valid teletex terminal identifier parameter
    // followed by a colon and the value. Dollar signs must be escaped
    int paramStartPos = pos;
    boolean escaped = false;
    while (pos < valueLength)
    {
      if (escaped)
      {
        pos++;
        continue;
      }

      c = valueString.charAt(pos++);
      if (c == '\\')
      {
        escaped = true;
        continue;
      }
      else if (c == '$')
      {
        final String paramStr =
            valueString.substring(paramStartPos, pos);

        final int colonPos = paramStr.indexOf(':');
        if (colonPos < 0)
        {

          invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_PARAM_NO_COLON
              .get(valueString));
          return false;
        }

        final String paramName = paramStr.substring(0, colonPos);
        if (!ALLOWED_TTX_PARAMETERS.contains(paramName))
        {

          invalidReason
              .append(ERR_ATTR_SYNTAX_TELETEXID_ILLEGAL_PARAMETER.get(
                  valueString, paramName));
          return false;
        }

        paramStartPos = pos;
      }
    }

    // We must be at the end of the value. Read the last parameter and
    // make sure it is valid.
    final String paramStr = valueString.substring(paramStartPos);
    final int colonPos = paramStr.indexOf(':');
    if (colonPos < 0)
    {

      invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_PARAM_NO_COLON
          .get(valueString));
      return false;
    }

    final String paramName = paramStr.substring(0, colonPos);
    if (!ALLOWED_TTX_PARAMETERS.contains(paramName))
    {

      invalidReason.append(ERR_ATTR_SYNTAX_TELETEXID_ILLEGAL_PARAMETER
          .get(valueString, paramName));
      return false;
    }

    // If we've gotten here, then the value must be valid.
    return true;
  }
}