/* 
 * 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 org.apache.felix.mosgi.jmx.httpconnector.mx4j.tools.adaptor.http;

import java.lang.reflect.Constructor;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.Comparator;
import java.util.Date;

import javax.management.ObjectInstance;

//SFR import javax.management.openmbean.OpenType;

/**
 * Contains utilities common to CommandProcessor objects
 *
 * @author <a href="mailto:tibu@users.sourceforge.net">Carlos Quiroz</a>
 * @author <a href="mailto:l.dobrev@lsnsoft.com">Lachezar Dobrev</a>
 * @version $Revision: 1.2 $
 */
public class CommandProcessorUtil
{
  // contains all date and date time format instances
  // for the current locale
  private static final DateFormat[] allFormats = new DateFormat[] {
    DateFormat.getDateInstance(),
    DateFormat.getTimeInstance(),
    DateFormat.getDateTimeInstance(),
    // first pure date format
    DateFormat.getDateInstance(DateFormat.SHORT),
    DateFormat.getDateInstance(DateFormat.MEDIUM),
    DateFormat.getDateInstance(DateFormat.LONG),
    DateFormat.getDateInstance(DateFormat.FULL),
    // pure time format
    DateFormat.getTimeInstance(DateFormat.SHORT),
    DateFormat.getTimeInstance(DateFormat.MEDIUM),
    DateFormat.getTimeInstance(DateFormat.LONG),
    DateFormat.getTimeInstance(DateFormat.FULL),
    // combinations
    DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT),
    DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM),
    DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.LONG),
    DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.FULL),

    DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.SHORT),
    DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM),
    DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG),
    DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.FULL),

    DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.SHORT),
    DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.MEDIUM),
    DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG),
    DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.FULL),

    DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.SHORT),
    DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.MEDIUM),
    DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.LONG),
    DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.FULL)
  };

  private static final String[] BASIC_TYPES = new String[] {
    "int", "long", "short", "byte", "float", "double", "boolean"
  };

  /**
   * Creates a parameter object of the given type containing a given value.
   * If the type is unknown null is returned
   *
   * @param parameterType Indicates the type of the parameter, for instance java.lang.String
   * @param parameterValue The value of the parameter as a String
   * @return an object of parameterType type and value parameterValue or null if the type is unknown
   * @exception Thrown in case there is a data conversion error
   */
  protected static Object createParameterValue(String parameterType, String parameterValue)
    throws Exception
  {
    if (parameterType.equals("java.lang.String"))
    {
      return parameterValue;
    }
    else if (parameterType.equals("java.lang.Integer") || parameterType.equals("int"))
    {
      return Integer.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Long") || parameterType.equals("long"))
    {
      return Long.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Short") || parameterType.equals("short"))
    {
      return Short.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Byte") || parameterType.equals("byte"))
    {
      return Byte.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Float") || parameterType.equals("float"))
    {
      return Float.valueOf(parameterValue);
    }
    // changed java.lang.dobule to java.lang.double bronwen
    else if (parameterType.equals("java.lang.Double") || parameterType.equals("double"))
    {
      return Double.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Boolean") || parameterType.equals("boolean"))
    {
      return Boolean.valueOf(parameterValue);
    }
    else if (parameterType.equals("java.lang.Void"))
    {
      return Void.TYPE;
    }
    else if (parameterType.equals("java.util.Date"))
    {
      // this is tricky since Date can be written in many formats
      // will use the Date format with current locale and several
      // different formats
      Date value = null;
      for (int i=0;i<allFormats.length;i++) {
        synchronized (allFormats[i]) {
          try {
            System.out.println(parameterValue + " " + allFormats[i]);
            value = allFormats[i].parse(parameterValue);
            // if succeful then break
            break;
          } catch (ParseException e) {
            // ignore, the format wasn't appropriate
          }
        }
      }
      if (value == null) {
        throw new ParseException("Not possible to parse", 0);
      }
      return value;
    }
    else if (parameterType.equals("java.lang.Number"))
    {
      Number value = null;
      // try first as a long
      try
      {
        value = Long.valueOf(parameterValue);
      }
      catch (NumberFormatException e)
      {
      }
      // if not try as a double
      if (value == null) {
        try {
          value = Double.valueOf(parameterValue);
        }
        catch (NumberFormatException e)
        {
        }
      }
      if (value == null) {
        throw new NumberFormatException("Not possible to parse");
      }
      return value;
    }
    if (parameterType.equals("java.lang.Character") || parameterType.equals("char"))
    {
      if ( parameterValue.length() > 0 )
      {
        return new Character(parameterValue.charAt(0));
      }
      else
      {
        throw new NumberFormatException("Can not initialize Character from empty String");
      }
    }
    // tests whether the classes have a single string parameter value
    // constructor. That covers the classes
    // javax.management.ObjectName
    // java.math.BigInteger
    // java.math.BigDecimal

    Class cls = null;
    java.lang.reflect.Constructor ctor = null;
    try
    {
      cls  = Class.forName(parameterType);
      ctor  = cls.getConstructor(new Class[] {String.class});
      return ctor.newInstance(new Object[] {parameterValue});
    }
    catch (ClassNotFoundException cnfe)
    {
      // Can not find class. Not in our ClassLoader?
      /** @todo Ask the MBeanServer to instantiate this class??? */
      throw new IllegalArgumentException("Invalid parameter type: " + parameterType);
    }
    catch (NoSuchMethodException nsme)
    {
      // No public String constructor.
      throw new IllegalArgumentException("Invalid parameter type: " + parameterType);
    }
    catch (Exception ex)
    {
      // Constructor might have thrown an exception?
      // Security Exception ?
      // IllegalAccessException? .... etc.
      // Just rethrow. We can do little here <shrug>
      /** @todo Log the exception */
      throw ex;
    }
  }

  /**
   * Checks if the given type is primitive of can be initialized from String.<br>
   * This is done by trying to load the class and checking if there is a public String
   * only constructor.
   *
   * @param parameterType Indicates the type of the parameter, for instance java.lang.String
   * @return true if the type is primitive or String initializable
   * @exception Thrown in case there is a data conversion error
   */

  protected static boolean canCreateParameterValue(String parameterType)
  {
    int count;
  /*
    count = OpenType.ALLOWED_CLASSNAMES.length;
    for (int i=0;i<count;i++)
    {
      if (OpenType.ALLOWED_CLASSNAMES[i].equals(parameterType))
      {
        return true;
      }
    }
    */
    count = BASIC_TYPES.length;
    for (int i=0;i<count;i++)
    {
      if (BASIC_TYPES[i].equals(parameterType))
      {
        return true;
      }
    }

    Class cls = null ;
    try
    {
      cls  = Class.forName(parameterType);
      cls.getConstructor(new Class[] {String.class});
      // Yes we can load the class and it has a public String constructor.
      return true;
    }
    catch (ClassNotFoundException cnfe)
    {
      // Can not find class. Not in our ClassLoader?
      return false;
    }
    catch (NoSuchMethodException nsme)
    {
      // No public String constructor.
      return false;
    }
    catch (Exception ex)
    {
      // Constructor might have thrown an exception?
      // Security Exception ?
      // IllegalAccessException? .... etc.
      // Just rethrow. We can do little here <shrug>
      return false;
    }
  }

  public static Comparator createObjectNameComparator()
  {
    return new ToStringComparator();
  }

  public static Comparator createObjectInstanceComparator()
  {
    return new ObjectInstanceComparator();
  }

  public static Comparator createConstructorComparator()
  {
    return new ConstructorComparator();
  }

  public static Comparator createClassComparator()
  {
    return new ToStringComparator();
  }

  private static class ToStringComparator implements Comparator {
    public int compare(Object o1, Object o2) {
      return o1.toString().compareTo(o2.toString());
    }
  }

  private static class ObjectInstanceComparator implements Comparator {
    private ToStringComparator comp = new ToStringComparator();
    public int compare(Object o1, Object o2) {
      ObjectInstance oi1 = (ObjectInstance)o1;
      ObjectInstance oi2 = (ObjectInstance)o2;
      return comp.compare(oi1.getObjectName(), oi2.getObjectName());
    }
  }

  private static class ConstructorComparator implements Comparator {
    public int compare(Object o1, Object o2) {
      Constructor c1 = (Constructor)o1;
      Constructor c2 = (Constructor)o2;
      // sort them by the parameter types;
      Class[] params1 = c1.getParameterTypes();
      Class[] params2 = c2.getParameterTypes();
      if (params1.length == params2.length)
      {
        for (int i=0;i<params1.length;i++)
        {
          if (!params1[i].equals(params2[i])) {
            return params2[i].toString().compareTo(params1[i].toString());
          }
        }
        return 0;
      }
      else
      {
        return params1.length - params2.length;
      }
    }
  }

}