/*
 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
 */
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you 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.
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 com.sun.org.apache.xpath.internal.compiler;

import com.sun.org.apache.xpath.internal.functions.Function;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
import javax.xml.transform.TransformerException;

The function table for XPath.
@LastModified
: Oct 2017/**
 * The function table for XPath.
 *
 * @LastModified: Oct 2017
 */
public class FunctionTable
{

  
The 'current()' id. /** The 'current()' id. */
  public static final int FUNC_CURRENT = 0;

  
The 'last()' id. /** The 'last()' id. */
  public static final int FUNC_LAST = 1;

  
The 'position()' id. /** The 'position()' id. */
  public static final int FUNC_POSITION = 2;

  
The 'count()' id. /** The 'count()' id. */
  public static final int FUNC_COUNT = 3;

  
The 'id()' id. /** The 'id()' id. */
  public static final int FUNC_ID = 4;

  
The 'key()' id (XSLT). /** The 'key()' id (XSLT). */
  public static final int FUNC_KEY = 5;

  
The 'local-name()' id. /** The 'local-name()' id. */
  public static final int FUNC_LOCAL_PART = 7;

  
The 'namespace-uri()' id. /** The 'namespace-uri()' id. */
  public static final int FUNC_NAMESPACE = 8;

  
The 'name()' id. /** The 'name()' id. */
  public static final int FUNC_QNAME = 9;

  
The 'generate-id()' id. /** The 'generate-id()' id. */
  public static final int FUNC_GENERATE_ID = 10;

  
The 'not()' id. /** The 'not()' id. */
  public static final int FUNC_NOT = 11;

  
The 'true()' id. /** The 'true()' id. */
  public static final int FUNC_TRUE = 12;

  
The 'false()' id. /** The 'false()' id. */
  public static final int FUNC_FALSE = 13;

  
The 'boolean()' id. /** The 'boolean()' id. */
  public static final int FUNC_BOOLEAN = 14;

  
The 'number()' id. /** The 'number()' id. */
  public static final int FUNC_NUMBER = 15;

  
The 'floor()' id. /** The 'floor()' id. */
  public static final int FUNC_FLOOR = 16;

  
The 'ceiling()' id. /** The 'ceiling()' id. */
  public static final int FUNC_CEILING = 17;

  
The 'round()' id. /** The 'round()' id. */
  public static final int FUNC_ROUND = 18;

  
The 'sum()' id. /** The 'sum()' id. */
  public static final int FUNC_SUM = 19;

  
The 'string()' id. /** The 'string()' id. */
  public static final int FUNC_STRING = 20;

  
The 'starts-with()' id. /** The 'starts-with()' id. */
  public static final int FUNC_STARTS_WITH = 21;

  
The 'contains()' id. /** The 'contains()' id. */
  public static final int FUNC_CONTAINS = 22;

  
The 'substring-before()' id. /** The 'substring-before()' id. */
  public static final int FUNC_SUBSTRING_BEFORE = 23;

  
The 'substring-after()' id. /** The 'substring-after()' id. */
  public static final int FUNC_SUBSTRING_AFTER = 24;

  
The 'normalize-space()' id. /** The 'normalize-space()' id. */
  public static final int FUNC_NORMALIZE_SPACE = 25;

  
The 'translate()' id. /** The 'translate()' id. */
  public static final int FUNC_TRANSLATE = 26;

  
The 'concat()' id. /** The 'concat()' id. */
  public static final int FUNC_CONCAT = 27;

  
The 'substring()' id. /** The 'substring()' id. */
  public static final int FUNC_SUBSTRING = 29;

  
The 'string-length()' id. /** The 'string-length()' id. */
  public static final int FUNC_STRING_LENGTH = 30;

  
The 'system-property()' id. /** The 'system-property()' id. */
  public static final int FUNC_SYSTEM_PROPERTY = 31;

  
The 'lang()' id. /** The 'lang()' id. */
  public static final int FUNC_LANG = 32;

  
The 'function-available()' id (XSLT). /** The 'function-available()' id (XSLT). */
  public static final int FUNC_EXT_FUNCTION_AVAILABLE = 33;

  
The 'element-available()' id (XSLT). /** The 'element-available()' id (XSLT). */
  public static final int FUNC_EXT_ELEM_AVAILABLE = 34;

  
The 'unparsed-entity-uri()' id (XSLT). /** The 'unparsed-entity-uri()' id (XSLT). */
  public static final int FUNC_UNPARSED_ENTITY_URI = 36;

  
The 'here()' id (XML Signature). /** The 'here()' id (XML Signature). */
  public static final int FUNC_HERE = 37;

  // Proprietary

  
The 'document-location()' id (Proprietary). /** The 'document-location()' id (Proprietary). */
  public static final int FUNC_DOCLOCATION = 35;

  
The function table.
/**
   * The function table.
   */
  private static Class<?> m_functions[];

  
Table of function name to function ID associations. /** Table of function name to function ID associations. */
  private static final Map<String, Integer> m_functionID = new HashMap<>();

  
The function table contains customized functions
/**
   * The function table contains customized functions
   */
  private Class<?> m_functions_customer[] = new Class<?>[NUM_ALLOWABLE_ADDINS];

  
Table of function name to function ID associations for customized functions
/**
   * Table of function name to function ID associations for customized functions
   */
  private Map<String, Integer> m_functionID_customer = new HashMap<>();

  
Number of built in functions.  Be sure to update this as
built-in functions are added.
/**
   * Number of built in functions.  Be sure to update this as
   * built-in functions are added.
   */
  private static final int NUM_BUILT_IN_FUNCS = 38;

  
Number of built-in functions that may be added.
/**
   * Number of built-in functions that may be added.
   */
  private static final int NUM_ALLOWABLE_ADDINS = 30;

  
The index to the next free function index.
/**
   * The index to the next free function index.
   */
  private int m_funcNextFreeIndex = NUM_BUILT_IN_FUNCS;

  static
  {
    m_functions = new Class<?>[NUM_BUILT_IN_FUNCS];
    m_functions[FUNC_CURRENT] = com.sun.org.apache.xpath.internal.functions.FuncCurrent.class;
    m_functions[FUNC_LAST] = com.sun.org.apache.xpath.internal.functions.FuncLast.class;
    m_functions[FUNC_POSITION] = com.sun.org.apache.xpath.internal.functions.FuncPosition.class;
    m_functions[FUNC_COUNT] = com.sun.org.apache.xpath.internal.functions.FuncCount.class;
    m_functions[FUNC_ID] = com.sun.org.apache.xpath.internal.functions.FuncId.class;
    // J2SE does not support Xalan interpretive
    // m_functions[FUNC_KEY] =
    //   com.sun.org.apache.xalan.internal.templates.FuncKey.class;
    m_functions[FUNC_LOCAL_PART] =
      com.sun.org.apache.xpath.internal.functions.FuncLocalPart.class;
    m_functions[FUNC_NAMESPACE] =
      com.sun.org.apache.xpath.internal.functions.FuncNamespace.class;
    m_functions[FUNC_QNAME] = com.sun.org.apache.xpath.internal.functions.FuncQname.class;
    m_functions[FUNC_GENERATE_ID] =
      com.sun.org.apache.xpath.internal.functions.FuncGenerateId.class;
    m_functions[FUNC_NOT] = com.sun.org.apache.xpath.internal.functions.FuncNot.class;
    m_functions[FUNC_TRUE] = com.sun.org.apache.xpath.internal.functions.FuncTrue.class;
    m_functions[FUNC_FALSE] = com.sun.org.apache.xpath.internal.functions.FuncFalse.class;
    m_functions[FUNC_BOOLEAN] = com.sun.org.apache.xpath.internal.functions.FuncBoolean.class;
    m_functions[FUNC_LANG] = com.sun.org.apache.xpath.internal.functions.FuncLang.class;
    m_functions[FUNC_NUMBER] = com.sun.org.apache.xpath.internal.functions.FuncNumber.class;
    m_functions[FUNC_FLOOR] = com.sun.org.apache.xpath.internal.functions.FuncFloor.class;
    m_functions[FUNC_CEILING] = com.sun.org.apache.xpath.internal.functions.FuncCeiling.class;
    m_functions[FUNC_ROUND] = com.sun.org.apache.xpath.internal.functions.FuncRound.class;
    m_functions[FUNC_SUM] = com.sun.org.apache.xpath.internal.functions.FuncSum.class;
    m_functions[FUNC_STRING] = com.sun.org.apache.xpath.internal.functions.FuncString.class;
    m_functions[FUNC_STARTS_WITH] =
      com.sun.org.apache.xpath.internal.functions.FuncStartsWith.class;
    m_functions[FUNC_CONTAINS] = com.sun.org.apache.xpath.internal.functions.FuncContains.class;
    m_functions[FUNC_SUBSTRING_BEFORE] =
      com.sun.org.apache.xpath.internal.functions.FuncSubstringBefore.class;
    m_functions[FUNC_SUBSTRING_AFTER] =
      com.sun.org.apache.xpath.internal.functions.FuncSubstringAfter.class;
    m_functions[FUNC_NORMALIZE_SPACE] =
      com.sun.org.apache.xpath.internal.functions.FuncNormalizeSpace.class;
    m_functions[FUNC_TRANSLATE] =
      com.sun.org.apache.xpath.internal.functions.FuncTranslate.class;
    m_functions[FUNC_CONCAT] = com.sun.org.apache.xpath.internal.functions.FuncConcat.class;
    m_functions[FUNC_SYSTEM_PROPERTY] =
      com.sun.org.apache.xpath.internal.functions.FuncSystemProperty.class;
    m_functions[FUNC_EXT_FUNCTION_AVAILABLE] =
      com.sun.org.apache.xpath.internal.functions.FuncExtFunctionAvailable.class;
    m_functions[FUNC_EXT_ELEM_AVAILABLE] =
      com.sun.org.apache.xpath.internal.functions.FuncExtElementAvailable.class;
    m_functions[FUNC_SUBSTRING] =
      com.sun.org.apache.xpath.internal.functions.FuncSubstring.class;
    m_functions[FUNC_STRING_LENGTH] =
      com.sun.org.apache.xpath.internal.functions.FuncStringLength.class;
    m_functions[FUNC_DOCLOCATION] =
      com.sun.org.apache.xpath.internal.functions.FuncDoclocation.class;
    m_functions[FUNC_UNPARSED_ENTITY_URI] =
      com.sun.org.apache.xpath.internal.functions.FuncUnparsedEntityURI.class;
    m_functions[FUNC_HERE] =
      com.sun.org.apache.xpath.internal.functions.FuncHere.class;
  }

  static{
          m_functionID.put(Keywords.FUNC_CURRENT_STRING,
                          FunctionTable.FUNC_CURRENT);
          m_functionID.put(Keywords.FUNC_LAST_STRING,
                          FunctionTable.FUNC_LAST);
          m_functionID.put(Keywords.FUNC_POSITION_STRING,
                          FunctionTable.FUNC_POSITION);
          m_functionID.put(Keywords.FUNC_COUNT_STRING,
                          FunctionTable.FUNC_COUNT);
          m_functionID.put(Keywords.FUNC_ID_STRING,
                          FunctionTable.FUNC_ID);
          m_functionID.put(Keywords.FUNC_KEY_STRING,
                          FunctionTable.FUNC_KEY);
          m_functionID.put(Keywords.FUNC_LOCAL_PART_STRING,
                          FunctionTable.FUNC_LOCAL_PART);
          m_functionID.put(Keywords.FUNC_NAMESPACE_STRING,
                          FunctionTable.FUNC_NAMESPACE);
          m_functionID.put(Keywords.FUNC_NAME_STRING,
                          FunctionTable.FUNC_QNAME);
          m_functionID.put(Keywords.FUNC_GENERATE_ID_STRING,
                          FunctionTable.FUNC_GENERATE_ID);
          m_functionID.put(Keywords.FUNC_NOT_STRING,
                          FunctionTable.FUNC_NOT);
          m_functionID.put(Keywords.FUNC_TRUE_STRING,
                          FunctionTable.FUNC_TRUE);
          m_functionID.put(Keywords.FUNC_FALSE_STRING,
                          FunctionTable.FUNC_FALSE);
          m_functionID.put(Keywords.FUNC_BOOLEAN_STRING,
                          FunctionTable.FUNC_BOOLEAN);
          m_functionID.put(Keywords.FUNC_LANG_STRING,
                          FunctionTable.FUNC_LANG);
          m_functionID.put(Keywords.FUNC_NUMBER_STRING,
                          FunctionTable.FUNC_NUMBER);
          m_functionID.put(Keywords.FUNC_FLOOR_STRING,
                          FunctionTable.FUNC_FLOOR);
          m_functionID.put(Keywords.FUNC_CEILING_STRING,
                          FunctionTable.FUNC_CEILING);
          m_functionID.put(Keywords.FUNC_ROUND_STRING,
                          FunctionTable.FUNC_ROUND);
          m_functionID.put(Keywords.FUNC_SUM_STRING,
                          FunctionTable.FUNC_SUM);
          m_functionID.put(Keywords.FUNC_STRING_STRING,
                          FunctionTable.FUNC_STRING);
          m_functionID.put(Keywords.FUNC_STARTS_WITH_STRING,
                          FunctionTable.FUNC_STARTS_WITH);
          m_functionID.put(Keywords.FUNC_CONTAINS_STRING,
                          FunctionTable.FUNC_CONTAINS);
          m_functionID.put(Keywords.FUNC_SUBSTRING_BEFORE_STRING,
                          FunctionTable.FUNC_SUBSTRING_BEFORE);
          m_functionID.put(Keywords.FUNC_SUBSTRING_AFTER_STRING,
                          FunctionTable.FUNC_SUBSTRING_AFTER);
          m_functionID.put(Keywords.FUNC_NORMALIZE_SPACE_STRING,
                          FunctionTable.FUNC_NORMALIZE_SPACE);
          m_functionID.put(Keywords.FUNC_TRANSLATE_STRING,
                          FunctionTable.FUNC_TRANSLATE);
          m_functionID.put(Keywords.FUNC_CONCAT_STRING,
                          FunctionTable.FUNC_CONCAT);
          m_functionID.put(Keywords.FUNC_SYSTEM_PROPERTY_STRING,
                          FunctionTable.FUNC_SYSTEM_PROPERTY);
          m_functionID.put(Keywords.FUNC_EXT_FUNCTION_AVAILABLE_STRING,
                        FunctionTable.FUNC_EXT_FUNCTION_AVAILABLE);
          m_functionID.put(Keywords.FUNC_EXT_ELEM_AVAILABLE_STRING,
                          FunctionTable.FUNC_EXT_ELEM_AVAILABLE);
          m_functionID.put(Keywords.FUNC_SUBSTRING_STRING,
                          FunctionTable.FUNC_SUBSTRING);
          m_functionID.put(Keywords.FUNC_STRING_LENGTH_STRING,
                          FunctionTable.FUNC_STRING_LENGTH);
          m_functionID.put(Keywords.FUNC_UNPARSED_ENTITY_URI_STRING,
                          FunctionTable.FUNC_UNPARSED_ENTITY_URI);
          m_functionID.put(Keywords.FUNC_DOCLOCATION_STRING,
                          FunctionTable.FUNC_DOCLOCATION);
          m_functionID.put(Keywords.FUNC_HERE_STRING,
                          FunctionTable.FUNC_HERE);
  }

  public FunctionTable(){
  }

  
Return the name of the a function in the static table. Needed to avoid
making the table publicly available.
/**
   * Return the name of the a function in the static table. Needed to avoid
   * making the table publicly available.
   */
  String getFunctionName(int funcID) {
      if (funcID < NUM_BUILT_IN_FUNCS) return m_functions[funcID].getName();
      else return m_functions_customer[funcID - NUM_BUILT_IN_FUNCS].getName();
  }

  
Obtain a new Function object from a function ID.
Params:
which –  The function ID, which may correspond to one of the FUNC_XXX values found in FunctionTable, but may be a value installed by an external module.
Throws:
TransformerException – if ClassNotFoundException,
   IllegalAccessException, or InstantiationException is thrown.
Returns:
a a new Function instance./**
   * Obtain a new Function object from a function ID.
   *
   * @param which  The function ID, which may correspond to one of the FUNC_XXX
   *    values found in {@link com.sun.org.apache.xpath.internal.compiler.FunctionTable}, but may
   *    be a value installed by an external module.
   *
   * @return a a new Function instance.
   *
   * @throws javax.xml.transform.TransformerException if ClassNotFoundException,
   *    IllegalAccessException, or InstantiationException is thrown.
   */
  Function getFunction(int which)
          throws javax.xml.transform.TransformerException
  {
          try{
              if (which < NUM_BUILT_IN_FUNCS) {
                  return (Function) m_functions[which].getConstructor().newInstance();
              } else {
                  Class<?> c =  m_functions_customer[which-NUM_BUILT_IN_FUNCS];
                  return (Function) c.getConstructor().newInstance();
              }
          }catch (InstantiationException | IllegalAccessException | SecurityException |
              IllegalArgumentException | InvocationTargetException | NoSuchMethodException ex){
              throw new TransformerException(ex.getMessage());
          }
  }

  
Obtain a function ID from a given function name
Params:
key – the function name in a java.lang.String format.
Returns:
a function ID, which may correspond to one of the FUNC_XXX values found in FunctionTable, but may be a value installed by an external module./**
   * Obtain a function ID from a given function name
   * @param key the function name in a java.lang.String format.
   * @return a function ID, which may correspond to one of the FUNC_XXX values
   * found in {@link com.sun.org.apache.xpath.internal.compiler.FunctionTable}, but may be a
   * value installed by an external module.
   */
  Integer getFunctionID(String key){
          Integer id = m_functionID_customer.get(key);
          if (null == id) id = m_functionID.get(key);
          return id;
  }

  
Install a built-in function.
Params:
name – The unqualified name of the function, must not be null
func – A Implementation of an XPath Function object.
Returns:
the position of the function in the internal index./**
   * Install a built-in function.
   * @param name The unqualified name of the function, must not be null
   * @param func A Implementation of an XPath Function object.
   * @return the position of the function in the internal index.
   */
  public int installFunction(String name, Class<?> func)
  {

    int funcIndex;
    Integer funcIndexObj = getFunctionID(name);

    if (func != null && !Function.class.isAssignableFrom(func)) {
        throw new ClassCastException(func.getName()
                  + " cannot be cast to "
                  + Function.class.getName());
    }

    if (null != funcIndexObj)
    {
      funcIndex = funcIndexObj;

      if (funcIndex < NUM_BUILT_IN_FUNCS){
              funcIndex = m_funcNextFreeIndex++;
              m_functionID_customer.put(name, funcIndex);
      }
      m_functions_customer[funcIndex - NUM_BUILT_IN_FUNCS] = func;
    }
    else
    {
            funcIndex = m_funcNextFreeIndex++;
            m_functions_customer[funcIndex-NUM_BUILT_IN_FUNCS] = func;
            m_functionID_customer.put(name, funcIndex);
    }
    return funcIndex;
  }

  
Tell if a built-in, non-namespaced function is available.
Params:
methName – The local name of the function.
Returns:
True if the function can be executed./**
   * Tell if a built-in, non-namespaced function is available.
   *
   * @param methName The local name of the function.
   *
   * @return True if the function can be executed.
   */
  public boolean functionAvailable(String methName)
  {
      Integer tblEntry = m_functionID.get(methName);
      if (null != tblEntry) return true;
      else{
              tblEntry = m_functionID_customer.get(methName);
              return (null != tblEntry);
      }
  }
}