/*
 * 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 2007-2009 Sun Microsystems, Inc.
 */

package org.opends.sdk;



import java.io.Serializable;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;

import com.sun.opends.sdk.util.Validator;



/**
 * A mutable sequence of localizable messages and their parameters. As messages
 * are appended they are translated to their string representation for storage
 * using the locale specified in the constructor.
 * <p>
 * Note that before you use this class you should consider whether it is
 * appropriate. In general composing messages by appending message to each other
 * may not produce a message that is formatted appropriately for all locales.
 * <p>
 * It is usually better to create messages by composition. In other words you
 * should create a base message that contains one or more string argument
 * specifiers (%s) and define other message objects to use as replacement
 * variables. In this way language translators have a change to reformat the
 * message for a particular locale if necessary.
 *
 * @see LocalizableMessage
 */
public final class LocalizableMessageBuilder implements Appendable,
    CharSequence, Serializable
{

  private static final long serialVersionUID = -3292823563904285315L;

  // Used internally to store appended messages.
  private final List<LocalizableMessage> messages = new LinkedList<LocalizableMessage>();



  /**
   * Creates a new message builder whose content is initially empty.
   */
  public LocalizableMessageBuilder()
  {
    // Nothing to do.
  }



  /**
   * Creates a new message builder whose content is initially equal to the
   * provided message.
   *
   * @param message
   *          The initial content of the message builder.
   * @throws NullPointerException
   *           If {@code message} was {@code null}.
   */
  public LocalizableMessageBuilder(final LocalizableMessage message)
      throws NullPointerException
  {
    append(message);
  }



  /**
   * Creates a new message builder whose content is initially equal to the
   * provided message builder.
   *
   * @param builder
   *          The initial content of the message builder.
   * @throws NullPointerException
   *           If {@code builder} was {@code null}.
   */
  public LocalizableMessageBuilder(final LocalizableMessageBuilder builder)
      throws NullPointerException
  {
    for (final LocalizableMessage message : builder.messages)
    {
      this.messages.add(message);
    }
  }



  /**
   * Creates a new message builder whose content is initially equal to the
   * {@code String} representation of the provided {@code Object}.
   *
   * @param object
   *          The initial content of the message builder, may be {@code null}.
   */
  public LocalizableMessageBuilder(final Object object)
  {
    append(object);
  }



  /**
   * Appends the provided character to this message builder.
   *
   * @param c
   *          The character to be appended.
   * @return A reference to this message builder.
   */
  public LocalizableMessageBuilder append(final char c)
  {
    return append(LocalizableMessage.valueOf(c));
  }



  /**
   * Appends the provided character sequence to this message builder.
   *
   * @param cs
   *          The character sequence to be appended.
   * @return A reference to this message builder.
   * @throws NullPointerException
   *           If {@code cs} was {@code null}.
   */
  public LocalizableMessageBuilder append(final CharSequence cs)
      throws NullPointerException
  {
    Validator.ensureNotNull(cs);
    return append((Object) cs);
  }



  /**
   * Appends a subsequence of the provided character sequence to this message
   * builder.
   * <p>
   * An invocation of this method of the form {@code append(cs, start, end)},
   * behaves in exactly the same way as the invocation
   *
   * <pre>
   * append(cs.subSequence(start, end))
   * </pre>
   *
   * @param cs
   *          The character sequence to be appended.
   * @param start
   *          The index of the first character in the subsequence.
   * @param end
   *          The index of the character following the last character in the
   *          subsequence.
   * @return A reference to this message builder.
   * @throws IndexOutOfBoundsException
   *           If {@code start} or {@code end} are negative, {@code start} is
   *           greater than {@code end}, or {@code end} is greater than {@code
   *           csq.length()}.
   * @throws NullPointerException
   *           If {@code cs} was {@code null}.
   */
  public LocalizableMessageBuilder append(final CharSequence cs,
      final int start, final int end) throws IndexOutOfBoundsException,
      NullPointerException
  {
    return append(cs.subSequence(start, end));
  }



  /**
   * Appends the provided integer to this message builder.
   *
   * @param value
   *          The integer to be appended.
   * @return A reference to this message builder.
   */
  public LocalizableMessageBuilder append(final int value)
  {
    return append(LocalizableMessage.valueOf(value));
  }



  /**
   * Appends the provided message to this message builder.
   *
   * @param message
   *          The message to be appended.
   * @return A reference to this message builder.
   * @throws NullPointerException
   *           If {@code message} was {@code null}.
   */
  public LocalizableMessageBuilder append(final LocalizableMessage message)
      throws NullPointerException
  {
    Validator.ensureNotNull(message);
    messages.add(message);
    return this;
  }



  /**
   * Appends the {@code String} representation of the provided {@code Object} to
   * this message builder.
   *
   * @param object
   *          The object to be appended, may be {@code null}.
   * @return A reference to this message builder.
   */
  public LocalizableMessageBuilder append(final Object object)
  {
    return append(LocalizableMessage.valueOf(object));
  }



  /**
   * Returns the {@code char} value at the specified index of the {@code String}
   * representation of this message builder in the default locale.
   *
   * @param index
   *          The index of the {@code char} value to be returned.
   * @return The specified {@code char} value.
   * @throws IndexOutOfBoundsException
   *           If the {@code index} argument is negative or not less than
   *           {@code length()}.
   */
  public char charAt(final int index) throws IndexOutOfBoundsException
  {
    return charAt(Locale.getDefault(), index);
  }



  /**
   * Returns the {@code char} value at the specified index of the {@code String}
   * representation of this message builder in the specified locale.
   *
   * @param locale
   *          The locale.
   * @param index
   *          The index of the {@code char} value to be returned.
   * @return The specified {@code char} value.
   * @throws IndexOutOfBoundsException
   *           If the {@code index} argument is negative or not less than
   *           {@code length()}.
   * @throws NullPointerException
   *           If {@code locale} was {@code null}.
   */
  public char charAt(final Locale locale, final int index)
      throws IndexOutOfBoundsException, NullPointerException
  {
    return toString(locale).charAt(index);
  }



  /**
   * Returns the length of the {@code String} representation of this message
   * builder in the default locale.
   *
   * @return The length of the {@code String} representation of this message
   *         builder in the default locale.
   */
  public int length()
  {
    return length(Locale.getDefault());
  }



  /**
   * Returns the length of the {@code String} representation of this message
   * builder in the specified locale.
   *
   * @param locale
   *          The locale.
   * @return The length of the {@code String} representation of this message
   *         builder in the specified locale.
   * @throws NullPointerException
   *           If {@code locale} was {@code null}.
   */
  public int length(final Locale locale) throws NullPointerException
  {
    return toString(locale).length();
  }



  /**
   * Returns a new {@code CharSequence} which is a subsequence of the {@code
   * String} representation of this message builder in the default locale. The
   * subsequence starts with the {@code char} value at the specified index and
   * ends with the {@code char} value at index {@code end - 1} . The length (in
   * {@code char}s) of the returned sequence is {@code end - start}, so if
   * {@code start == end} then an empty sequence is returned.
   *
   * @param start
   *          The start index, inclusive.
   * @param end
   *          The end index, exclusive.
   * @return The specified subsequence.
   * @throws IndexOutOfBoundsException
   *           If {@code start} or {@code end} are negative, if {@code end} is
   *           greater than {@code length()}, or if {@code start} is greater
   *           than {@code end}.
   */
  public CharSequence subSequence(final int start, final int end)
      throws IndexOutOfBoundsException
  {
    return subSequence(Locale.getDefault(), start, end);
  }



  /**
   * Returns a new {@code CharSequence} which is a subsequence of the {@code
   * String} representation of this message builder in the specified locale. The
   * subsequence starts with the {@code char} value at the specified index and
   * ends with the {@code char} value at index {@code end - 1} . The length (in
   * {@code char}s) of the returned sequence is {@code end - start}, so if
   * {@code start == end} then an empty sequence is returned.
   *
   * @param locale
   *          The locale.
   * @param start
   *          The start index, inclusive.
   * @param end
   *          The end index, exclusive.
   * @return The specified subsequence.
   * @throws IndexOutOfBoundsException
   *           If {@code start} or {@code end} are negative, if {@code end} is
   *           greater than {@code length()}, or if {@code start} is greater
   *           than {@code end}.
   * @throws NullPointerException
   *           If {@code locale} was {@code null}.
   */
  public CharSequence subSequence(final Locale locale, final int start,
      final int end) throws IndexOutOfBoundsException, NullPointerException
  {
    return toString(locale).subSequence(start, end);
  }



  /**
   * Returns the {@link LocalizableMessage} representation of this message
   * builder. Subsequent changes to this message builder will not modify the
   * returned {@code LocalizableMessage}.
   *
   * @return The {@code LocalizableMessage} representation of this message
   *         builder.
   */
  public LocalizableMessage toMessage()
  {
    if (messages.isEmpty())
    {
      return LocalizableMessage.EMPTY;
    }

    final int sz = messages.size();
    final StringBuffer fmtString = new StringBuffer(sz * 2);
    for (int i = 0; i < sz; i++)
    {
      fmtString.append("%s");
    }

    return LocalizableMessage.raw(fmtString, messages.toArray());
  }



  /**
   * Returns the {@code String} representation of this message builder in the
   * default locale.
   *
   * @return The {@code String} representation of this message builder.
   */
  @Override
  public String toString()
  {
    return toString(Locale.getDefault());
  }



  /**
   * Returns the {@code String} representation of this message builder in the
   * specified locale.
   *
   * @param locale
   *          The locale.
   * @return The {@code String} representation of this message builder.
   * @throws NullPointerException
   *           If {@code locale} was {@code null}.
   */
  public String toString(final Locale locale) throws NullPointerException
  {
    final StringBuilder builder = new StringBuilder();
    for (final LocalizableMessage message : messages)
    {
      builder.append(message.toString(locale));
    }
    return builder.toString();
  }

}