//
// JavaMethod.java : Method の wrapper クラス定義 (一般 Java Class 向け)
//
//              This is a part of miolisp sourcefile
//              Copyright (C) 1998  Nishiyama, Naoki / Mio software lab. 
//
//  This program 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.
//
//  This program 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.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

import java.lang.reflect.* ;

class JavaMethod {
  static final int INITSIZE = 2  ;  // Initial size of m
  static final int ADDSIZE  = 10 ;  // Amount of increase

  int nmethods = 0 ;               // Number of registered methods 
  public Method[] m ;              // Array of same name methods
  JavaMethod() {m = new Method[INITSIZE];}
  JavaMethod(Method x) { this() ; m[0] = x ; nmethods++ ; }

  void addMethod(Method x) {
    // reject same method
    for (int i = 0 ; i < m.length ; i++) {
      if (m[i] == x) return ;
    }

    if (nmethods >= m.length) {
      Method[] nm = new Method[m.length + ADDSIZE] ;
      for (int i = 0 ; i < m.length ; i++) nm[i] = m[i] ; // copy m
      m = nm ; // dispose m
    }

    m[nmethods++] = x ;
  }

  void pull1st(int index) {
    if (index >= nmethods) return ;
    Method tmp = m[0] ;
    m[0] = m[index] ;
    m[index] = tmp ;
  }

  // Evaluate with suitable method
  Object eval(Object cd,Environment e) throws Exception {
    Cons c = Evalutil.mustbecons("JavaMethod :",cd) ;
    Object args = Evalutil.evalall(-1,-1,c.cdr,e) ;
    Object[] argarray = Evalutil.listtoarg(args) ;

    for (int i=0;i < nmethods;i++) {
      try {
//        System.out.println("Applying->"+m[i]) ;
        Object r = m[i].invoke(c.car,argarray) ;
        if (i != 0) pull1st(i) ; 
        return r ;
      } catch(IllegalArgumentException ex) {
        if (i+1 < nmethods) continue ; // fail , but try next ...
        throw (Exception)ex ; // all methods failed. 
      } catch(InvocationTargetException ex) {
        throw (Exception)ex.getTargetException() ;
      } catch(Exception ex) {
        throw ex ;
      }
    }
    return null ; // Never come here ....
  } 
}