/*
 * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.quercus.env;

import com.caucho.quercus.expr.Expr;
import com.caucho.quercus.function.AbstractFunction;

/**
 * Represents the introspected static function information.
 */
abstract public class AbstractJavaMethod extends AbstractFunction
{
  /**
   * Returns the minimally required number of arguments.
   */
  abstract public int getMinArgLength();

  /**
   * Returns the maximum number of arguments allowed.
   */
  abstract public int getMaxArgLength();
  
  /**
   * Returns true if the function can take in unlimited number of args.
   */
  abstract public boolean getHasRestArgs();
  
  abstract public int getMarshalingCost(Value []args);
  
  abstract public int getMarshalingCost(Expr []args);

  public Class<?> getJavaDeclaringClass()
  {
    return null;
  }
  
  public Class<?>[] getJavaParameterTypes()
  {
    return null;
  }
  
  /**
   * Returns an overloaded java method.
   */
  public AbstractJavaMethod overload(AbstractJavaMethod fun)
  {
    // same method can occur for interfaces and overrides
    if (isSameMethod(this, fun)) {
      if (getJavaDeclaringClass().isAssignableFrom(fun.getJavaDeclaringClass()))
        return this;
      else if (fun.getJavaDeclaringClass().isAssignableFrom(getJavaDeclaringClass()))
        return fun;
      else
        return this;
    }
      
    AbstractJavaMethod method = new JavaOverloadMethod(this);
    
    method = method.overload(fun);
    
    return method;
  }

  /**
   * Checks for the same method, e.g. for multiple interfaces declaring
   * the same method.
   */
  private boolean isSameMethod(AbstractJavaMethod funA,
                               AbstractJavaMethod funB)
  {
    Class []paramTypesA = funA.getJavaParameterTypes();
    Class []paramTypesB = funB.getJavaParameterTypes();

    if (paramTypesA == null || paramTypesB == null)
      return false;

    if (paramTypesA.length != paramTypesB.length)
      return false;

    for (int i = 0; i < paramTypesA.length; i++) {
      if (! paramTypesA[i].equals(paramTypesB[i]))
        return false;
    }

    return true;
  }


  abstract public Value callMethod(Env env, Value qThis, Value []args);
  
  /**
   * Evaluates the function, returning a copy
   */
  @Override
  public Value callCopy(Env env, Value []args)
  {
    return call(env, args);
  }

  @Override
  public Value call(Env env, Value []args)
  {
    return callMethod(env, null, args);
  }

  @Override
  public Value call(Env env)
  {
    return callMethod(env, null, new Value[0]);
  }

  @Override
  public Value call(Env env, Value a1)
  {
    return callMethod(env, null, new Value[] {a1});
  }

  @Override
  public Value call(Env env, Value a1, Value a2)
  {
    return callMethod(env, null, new Value[] {a1, a2});
  }

  @Override
  public Value call(Env env, Value a1, Value a2, Value a3)
  {
    return callMethod(env, null, new Value[] {a1, a2, a3});
  }

  @Override
  public Value call(Env env,
                    Value a1, Value a2, Value a3, Value a4)
  {
    return callMethod(env, null, new Value[] {a1, a2, a3, a4});
  }

  @Override
  public Value call(Env env,
                    Value a1, Value a2, Value a3, Value a4, Value a5)
  {
    return callMethod(env, null, new Value[] {a1, a2, a3, a4, a5});
  }

  @Override
  public Value callMethod(Env env, Value qThis)
  {
    return callMethod(env, qThis, new Value[0]);
  }

  @Override
  public Value callMethod(Env env, Value qThis, Value a1)
  {
    return callMethod(env, qThis, new Value[] {a1});
  }

  @Override
  public Value callMethod(Env env, Value qThis, Value a1, Value a2)
  {
    return callMethod(env, qThis, new Value[] {a1, a2});
  }

  @Override
  public Value callMethod(Env env, Value qThis, Value a1, Value a2, Value a3)
  {
    return callMethod(env, qThis, new Value[] {a1, a2, a3});
  }

  @Override
  public Value callMethod(Env env, Value qThis,
                          Value a1, Value a2, Value a3, Value a4)
  {
    return callMethod(env, qThis, new Value[] {a1, a2, a3, a4});
  }

  @Override
  public Value callMethod(Env env, Value qThis,
                          Value a1, Value a2, Value a3, Value a4, Value a5)
  {
    return callMethod(env, qThis, new Value[] {a1, a2, a3, a4, a5});
  }
}
