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) 2002-2004 Anders Bengtsson 
Copyright (C) 2004 Stefan Matthias Aust 
Copyright (C) 2004 Jan Arne Petersen 
Copyright (C) 2004 David Corbin 
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) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * Copyright (C) 2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2004 David Corbin <dcorbin@users.sourceforge.net>
 *
 * 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.javasupport;

import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;

import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.RubyBoolean;
import org.jruby.RubyClass;
import org.jruby.RubyFixnum;
import org.jruby.RubyString;
import org.jruby.anno.JRubyMethod;
import org.jruby.exceptions.JumpException;
import org.jruby.exceptions.RaiseException;
import org.jruby.runtime.Helpers;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.cli.Options;
import static org.jruby.javasupport.JavaClass.toRubyArray;

public abstract class JavaCallable extends JavaAccessibleObject implements ParameterTypes {

    protected final Class<?>[] parameterTypes;

    private static final boolean REWRITE_JAVA_TRACE = Options.REWRITE_JAVA_TRACE.load();

    public JavaCallable(Ruby runtime, RubyClass rubyClass, Class<?>[] parameterTypes) {
        super(runtime, rubyClass);
        this.parameterTypes = parameterTypes;
    }

    public static void registerRubyMethods(Ruby runtime, RubyClass result) {
        result.defineAnnotatedMethods(JavaCallable.class);
    }

    public final int getArity() { return parameterTypes.length; }

    public final Class<?>[] getParameterTypes() { return parameterTypes; }

    //public abstract int getArity();
    //public abstract Class<?>[] getParameterTypes();
    public abstract int getModifiers();
    public abstract Class<?>[] getExceptionTypes();
    public abstract Type[] getGenericExceptionTypes();
    public abstract Type[] getGenericParameterTypes();
    public abstract Annotation[][] getParameterAnnotations();
    public abstract boolean isVarArgs();
    public abstract String toGenericString();

    
Returns:
the name used in the head of the string returned from inspect()/**
     * @return the name used in the head of the string returned from inspect()
     */
    protected abstract String nameOnInspection();

    @JRubyMethod
    public final RubyFixnum arity() {
        return getRuntime().newFixnum(getArity());
    }

    @JRubyMethod(name = { "argument_types", "parameter_types" })
    public final RubyArray parameter_types() {
        return toRubyArray(getRuntime(), getParameterTypes());
    }

    @JRubyMethod
    public RubyArray exception_types() {
        return toRubyArray(getRuntime(), getExceptionTypes());
    }

    @JRubyMethod
    public IRubyObject generic_parameter_types() {
        return Java.getInstance(getRuntime(), getGenericParameterTypes());
    }

    @JRubyMethod
    public IRubyObject generic_exception_types() {
        return Java.getInstance(getRuntime(), getGenericExceptionTypes());
    }

    @JRubyMethod
    public IRubyObject parameter_annotations() {
        return Java.getInstance(getRuntime(), getParameterAnnotations());
    }

    @JRubyMethod(name = "varargs?")
    public RubyBoolean varargs_p() {
        return getRuntime().newBoolean(isVarArgs());
    }

    @JRubyMethod
    public RubyString to_generic_string() {
        return getRuntime().newString(toGenericString());
    }

    @JRubyMethod(name = "public?")
    public RubyBoolean public_p() {
        return RubyBoolean.newBoolean(getRuntime(), Modifier.isPublic(getModifiers()));
    }

    protected final void checkArity(final int length) {
        if ( length != getArity() ) {
            throw getRuntime().newArgumentError(length, getArity());
        }
    }

    final Object[] convertArguments(final IRubyObject[] args) {
        return JavaUtil.convertArguments(args, parameterTypes, 0);
    }

    final Object[] convertArguments(final IRubyObject[] args, int offset) {
        return JavaUtil.convertArguments(args, parameterTypes, offset);
    }

    protected final IRubyObject handleThrowable(ThreadContext context, final Throwable ex) {
        if ( ex instanceof JumpException ) {
            // RaiseException (from the Ruby side) is expected to already
            // have its stack-trace rewritten - no need to do it again ...
            throw (JumpException) ex;
        }

        if (REWRITE_JAVA_TRACE) {
            Helpers.rewriteStackTraceAndThrow(context, ex);
        }

        Helpers.throwException(ex);
        return null; // not reached
    }

    protected final IRubyObject handleInvocationTargetEx(ThreadContext context, InvocationTargetException ex) {
        return handleThrowable(context, ex.getTargetException());
    }

    final IRubyObject handleIllegalAccessEx(final IllegalAccessException ex, Member target) throws RaiseException {
        throw getRuntime().newTypeError("illegal access on '" + target.getName() + "': " + ex.getMessage());
    }

    final IRubyObject handleIllegalAccessEx(final IllegalAccessException ex, Constructor target)  throws RaiseException {
        throw getRuntime().newTypeError("illegal access on constructor for type '" + target.getDeclaringClass().getSimpleName() + "': " + ex.getMessage());
    }

    final IRubyObject handlelIllegalArgumentEx(final IllegalArgumentException ex, Method target, Object... arguments) throws RaiseException {
        final StringBuilder msg = new StringBuilder(64);
        msg.append("for method ").append( target.getDeclaringClass().getSimpleName() )
           .append('.').append( target.getName() );
        msg.append(" expected "); dumpParameterTypes(msg);
        msg.append("; got: "); dumpArgTypes(arguments, msg);
        msg.append("; error: ").append( ex.getMessage() );
        throw getRuntime().newTypeError( msg.toString() );
    }

    final IRubyObject handlelIllegalArgumentEx(final IllegalArgumentException ex, Constructor target, Object... arguments) throws RaiseException {
        return handlelIllegalArgumentEx(ex, target, true, arguments);
    }

    final IRubyObject handlelIllegalArgumentEx(final IllegalArgumentException ex, Constructor target, final boolean targetInfo, Object... arguments) throws RaiseException {
        final StringBuilder msg = new StringBuilder(64);
        if ( targetInfo ) {
            msg.append("for constructor of type ").append( target.getDeclaringClass().getSimpleName() );
        }
        msg.append(" expected "); dumpParameterTypes(msg);
        msg.append("; got: "); dumpArgTypes(arguments, msg);
        msg.append("; error: ").append( ex.getMessage() );
        throw getRuntime().newTypeError( msg.toString() );
    }

    private void dumpParameterTypes(final StringBuilder str) {
        str.append('[');
        inspectParameterTypes(str, this, false);
        str.append(']');
    }

    static CharSequence dumpArgTypes(final Object[] args, final StringBuilder str) {
        str.append('[');
        for ( int i = 0; i < args.length; i++ ) {
            if ( i > 0 ) str.append(',');
            if ( args[i] == null ) str.append("null");
            else str.append( args[i].getClass().getName() );
        }
        str.append(']');
        return str;
    }

    public static StringBuilder inspectParameterTypes(
        final StringBuilder str, final ParameterTypes target) {
        return inspectParameterTypes(str, target, true);
    }

    private static StringBuilder inspectParameterTypes(
        final StringBuilder str, final ParameterTypes target, final boolean brackets) {
        if ( brackets ) str.append('(');
        final Class<?>[] types = target.getParameterTypes();
        for ( int i = 0; i < types.length; i++ ) {
            str.append( types[i].getName() );
            if ( i < types.length - 1 ) str.append(',');
        }
        if ( brackets ) str.append(')');
        return str;
    }

}