/**
 * 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 1999-2000 (C) Intalio, Inc. All Rights Reserved.
 */
package org.exolab.javasource;

/**
 * A utility class used to validate identifiers and class names.
 *
 * @author <a href="mailto:keith AT kvisco DOT com">Keith Visco</a>
 * @version $Revision$ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $
 */
public final class JNaming {
  // --------------------------------------------------------------------------

  /**
   * Reserved keywords in Java as of Java 5.
   */
  private static final String[] KEYWORDS = {"abstract", "boolean", "break", "byte", "case", "catch",
      "char", "class", "const", "continue", "default", "do", "double", "else", "enum", "extends",
      "false", "final", "finally", "float", "for", "goto", "if", "implements", "import",
      "instanceof", "int", "interface", "long", "native", "new", "null", "package", "private",
      "protected", "public", "return", "short", "static", "super", "switch", "synchronized", "this",
      "throw", "throws", "transient", "true", "try", "void", "volatile", "while"};

  /**
   * Collection classes in Java as of Java 5.
   */
  private static final String[] COLLECTIONS = {"ArrayList", "List", "Set", "Collection", "Vector",
      "Hashtable", "Map", "HashMap", "HashSet", "TreeSet", "Enumeration", "Iterator",
      "ListIterator", "SortedSet", "SortedMap", "Queue", "EnumSet", "EnumMap", "IdentityHashMap",
      "LinkedHashMap", "LinkedHashSet", "LinkedList", "Stack", "TreeMap", "WeakHashMap"};

  /**
   * Classes in java.lang.* as of Java 5.
   */
  private static final String[] JAVA_LANG = {
      // Interfaces in java.lang.*
      "Appendable", "CharSequence", "Cloneable", "Comparable", "Iterable", "Readable", "Runnable",
      // Classes in java.lang.*
      "Boolean", "Byte", "Character", "Class", "ClassLoader", "Compiler", "Double", "Enum", "Float",
      "InheritableThreadLocal", "Integer", "Long", "Math", "Number", "Object", "Package", "Process",
      "ProcessBuilder", "Runtime", "RuntimePermission", "SecurityManager", "Short",
      "StackTraceElement", "StrictMath", "String", "StringBuffer", "StringBuilder", "System",
      "Thread", "ThreadGroup", "ThreadLocal", "Throwable", "Void",
      // Exceptions in java.lang.*
      "ArithmeticException", "ArrayIndexOutOfBoundsException", "ArrayStoreException",
      "ClassCastException", "ClassNotFoundException", "CloneNotSupportedException",
      "EnumConstantNotPresentException", "Exception", "IllegalAccessException",
      "IllegalArgumentException", "IllegalMonitorStateException", "IllegalStateException",
      "IllegalThreadStateException", "IndexOutOfBoundsException", "InstantiationException",
      "InterruptedException", "NegativeArraySizeException", "NoSuchFieldException",
      "NoSuchMethodException", "NullPointerException", "NumberFormatException", "RuntimeException",
      "SecurityException", "StringIndexOutOfBoundsException", "TypeNotPresentException",
      "UnsupportedOperationException",
      // Errors in java.lang.*
      "AbstractMethodError", "AssertionError", "ClassCircularityError", "ClassFormatError", "Error",
      "ExceptionInInitializerError", "IllegalAccessError", "IncompatibleClassChangeError",
      "InstantiationError", "InternalError", "LinkageError", "NoClassDefFoundError",
      "NoSuchFieldError", "NoSuchMethodError", "OutOfMemoryError", "StackOverflowError",
      "ThreadDeath", "UnknownError", "UnsatisfiedLinkError", "UnsupportedClassVersionError",
      "VerifyError", "VirtualMachineError",
      // Annotation types in java.lang.*
      "Deprecated", "Override", "SuppressWarnings"};

  /**
   * Field names used within Castor that prevent a user from using the same name as an element
   * without using a mapping file. Some fields that Castor uses depend on the contents of the
   * schema, so we only warn. <br/>
   * Reserved:
   * 
   * <pre>
   * _items -- might be fetched using getXXXXItems where XXX == class name
   * _content
   * _choiceValue
   * _anyObject
   * </pre>
   */
  private static final String[] CASTOR_RESERVED = {"Content", "MenuItem",};

  /**
   * Special reserved names within Windows that prevent a user from using the same name as an
   * element without using a mapping file. Windows will not allow the use of any of these names with
   * any case with any extension. At least, not without contortions.
   * 
   * @see <a href=
   *      "http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/naming_a_file.asp">
   *      The MSDN web page on file naming</a>
   */
  private static final String[] WINDOWS_RESERVED =
      {"CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8",
          "COM9", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",};

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

  /**
   * As we're a static utility class, our constructor is private.
   */
  private JNaming() {
    super();
  }

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

  /**
   * Returns true if the given String is a Java keyword which will cause a problem when used as a
   * variable name.
   *
   * @param name The String to check against the list of keywords.
   * @return True if the given String is a Java keyword which will cause a problem when used as a
   *         variable name.
   */
  public static boolean isKeyword(final String name) {
    if (name == null) {
      return false;
    }
    for (String keyword : KEYWORDS) {
      if (keyword.equals(name)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns true if the given String is a parameterized Java collection. object keyword which will
   * cause a problem when used as a variable name
   *
   * @param name The String to check as a parameterized Java collection.
   * @return True if the given String is a parameterized Java collection object keyword which will
   *         cause a problem when used as a variable name.
   */
  public static boolean isParameterizedCollectionsObject(final String name) {
    if (name == null) {
      return false;
    }
    for (String collection : COLLECTIONS) {
      if (name.indexOf(collection) != -1) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns true if the given String is a Java class in java.lang.* which will cause a problem when
   * used as a variable name.
   *
   * @param name The String to check against the list of keywords.
   * @return True if the given String is a Java class in java.lang.* which will cause a problem when
   *         used as a variable name.
   */
  public static boolean isInJavaLang(final String name) {
    if (name == null) {
      return false;
    }
    for (String javaLang : JAVA_LANG) {
      if (javaLang.equals(name)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns true if the given String is a reserved name by Castor which may cause a problem when
   * used as a variable name. Some fields that Castor uses depend on the contents of the schema, so
   * we only warn.
   *
   * @param name The String to check against the list of keywords.
   * @return True if the given String is a reserved name by Castor which may cause a problem when
   *         used as a variable name.
   */
  public static boolean isReservedByCastor(final String name) {
    if (name == null) {
      return false;
    }
    for (String reserved : CASTOR_RESERVED) {
      if (reserved.equals(name)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns true if the given String is a reserved name by the Windows filesystem which will cause
   * a problem when used as a class name under Windows.
   *
   * @param name The String to check against the list of keywords.
   * @return True if the given String is a reserved name by Castor which may cause a problem when
   *         used as a variable name.
   */
  public static boolean isReservedByWindows(final String name) {
    if (name == null) {
      return false;
    }
    for (String windowsReserved : WINDOWS_RESERVED) {
      if (windowsReserved.equalsIgnoreCase(name)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns true if the given String matches the production of a valid Java identifier.
   *
   * @param string The String to check the production of.
   * @return True if the given String matches the production of a valid Java name, otherwise false.
   */
  public static boolean isValidJavaIdentifier(final String string) {
    if ((string == null) || (string.length() == 0)) {
      return false;
    }

    char[] chars = string.toCharArray();

    if (isParameterizedCollectionsObject(string)) {
      return true;
    }

    // -- make sure starting character is valid
    if (!Character.isJavaIdentifierStart(chars[0])) {
      return false;
    }

    for (char ch : chars) {
      if (!Character.isJavaIdentifierPart(ch)) {
        return false;
      }
    }
    if (isKeyword(string)) {
      return false;
    }
    return true;
  }

  /**
   * Returns the package name from the given class name.
   *
   * @param className An arbitrary class name, optionally including a package.
   * @return The package name from the given class name.
   */
  public static String getPackageFromClassName(final String className) {
    if (className == null) {
      return null;
    }
    int idx = className.lastIndexOf('.');
    if (idx > 0) {
      return className.substring(0, idx);
    }
    return null;
  }

  /**
   * Returns the local class name from the given fully qualified class name.
   *
   * @param className An arbitrary class name, optionally including a package.
   * @return The local name from the given class name.
   */
  public static String getLocalNameFromClassName(final String className) {
    if (className == null) {
      return null;
    }
    int idx = className.lastIndexOf('.');
    if (idx > 0) {
      return className.substring(idx + 1);
    }
    return className;
  }

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