BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2002 Jan Arne Petersen 
Copyright (C) 2002-2004 Anders Bengtsson 
Copyright (C) 2004 Thomas E Enebo 
Copyright (C) 2004 Stefan Matthias Aust 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * 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.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import org.jruby.internal.runtime.methods.JavaMethod;
import org.jruby.runtime.Arity;
import org.jruby.runtime.Block;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.Visibility;
import org.jruby.runtime.builtin.IRubyObject;

Author:
jpetersen/**
 * 
 * @author jpetersen
 */
public final class TopSelfFactory {

    
Constructor for TopSelfFactory.
/**
     * Constructor for TopSelfFactory.
     */
    private TopSelfFactory() {
        super();
    }

    public static IRubyObject createTopSelf(final Ruby runtime) {
        return createTopSelf(runtime, false);
    }
    
    public static IRubyObject createTopSelf(final Ruby runtime, final boolean wrapper) {
        IRubyObject topSelf = new RubyObject(runtime, runtime.getObject());

        final RubyClass singletonClass = topSelf.getSingletonClass();

        singletonClass.addMethod("to_s", new JavaMethod.JavaMethodZero(singletonClass, Visibility.PUBLIC, "to_s") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name) {
                return runtime.newString("main");
            }
        });
        singletonClass.defineAlias("inspect", "to_s");
        
        // The following three methods must be defined fast, since they expect to modify the current frame
        // (i.e. they expect no frame will be allocated for them). JRUBY-1185.
        singletonClass.addMethod("include", new JavaMethod.JavaMethodN(singletonClass, Visibility.PRIVATE, "include") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                return context.runtime.getObject().include(args);
            }
        });
        
        singletonClass.addMethod("public", new JavaMethod.JavaMethodN(singletonClass, Visibility.PRIVATE, "public") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                return context.runtime.getObject().rbPublic(context, args);
            }
        });
        
        singletonClass.addMethod("private", new JavaMethod.JavaMethodN(singletonClass, Visibility.PRIVATE, "private") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                return context.runtime.getObject().rbPrivate(context, args);
            }
        });

        final RubyClass klass = wrapper ? singletonClass : runtime.getObject();
        singletonClass.addMethod("define_method", new JavaMethod.JavaMethodOneOrTwoBlock(singletonClass, Visibility.PRIVATE, "define_method") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, Block block) {
                if (klass == singletonClass) warnWrapper(context);
                return klass.defineMethodFromBlock(context, arg0, block, Visibility.PUBLIC);
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, Block block) {
                if (klass == singletonClass) warnWrapper(context);
                return klass.defineMethodFromCallable(context, arg0, arg1, Visibility.PUBLIC);
            }
        });

        singletonClass.addMethod("using", new JavaMethod.JavaMethodN(singletonClass, Visibility.PRIVATE, "using") {
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                Arity.checkArgumentCount(context.runtime, args, 1, 1);
                RubyModule cref = context.getCurrentStaticScope().getOverlayModuleForWrite(context);
                // unclear what the equivalent check would be for us
//                rb_control_frame_t * prev_cfp = previous_frame(GET_THREAD());
//
//                if (CREF_NEXT(cref) || (prev_cfp && prev_cfp->me)) {
//                    rb_raise(rb_eRuntimeError,
//                            "main.using is permitted only at toplevel");
//                }
                RubyModule.usingModule(context, cref, args[0]);
                return self;
            }
        });
        
        return topSelf;
    }

    private static void warnWrapper(ThreadContext context) {
        context.runtime.getWarnings().warning("main.define_method in the wrapped load is effective only in wrapper module");
    }
}