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/***** 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) 2002-2004 Jan Arne Petersen 
 * Copyright (C) 2004-2005 Thomas E Enebo 
 * Copyright (C) 2004 Stefan Matthias Aust 
 * Copyright (C) 2004 David Corbin 
 * Copyright (C) 2005 Charles O Nutter 
 * Copyright (C) 2007 William N Dortch 
 *
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 * 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"),
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package org.jruby.javasupport;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;

import org.jruby.Ruby;
import org.jruby.RubyBoolean;
import org.jruby.RubyClass;
import org.jruby.RubyModule;
import org.jruby.RubyString;
import org.jruby.anno.JRubyClass;
import org.jruby.anno.JRubyMethod;
import org.jruby.exceptions.RaiseException;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;

@JRubyClass(name="Java::JavaField")
public class JavaField extends JavaAccessibleObject {

    private final Field field;

    public final Field getValue() { return field; }

    public static RubyClass createJavaFieldClass(Ruby runtime, RubyModule javaModule) {
        // TODO: NOT_ALLOCATABLE_ALLOCATOR is probably ok here, since we don't intend for people to monkey with
        // this type and it can't be marshalled. Confirm. JRUBY-415
        RubyClass result = javaModule.defineClassUnder("JavaField", runtime.getObject(), ObjectAllocator.NOT_ALLOCATABLE_ALLOCATOR);

        JavaAccessibleObject.registerRubyMethods(runtime, result);

        result.defineAnnotatedMethods(JavaField.class);

        return result;
    }

    public JavaField(Ruby runtime, Field field) {
        super(runtime, runtime.getJavaSupport().getJavaFieldClass());
        this.field = field;
    }

    public final boolean equals(Object other) {
        return other instanceof JavaField && this.field.equals( ((JavaField) other).field );
    }

    public final int hashCode() {
        return field.hashCode();
    }

    @JRubyMethod
    public RubyString value_type() {
        return getRuntime().newString(field.getType().getName());
    }

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

    @JRubyMethod(name = "static?")
    public RubyBoolean static_p() {
        return getRuntime().newBoolean(Modifier.isStatic(field.getModifiers()));
    }

    @JRubyMethod(name = "enum_constant?")
    public RubyBoolean enum_constant_p() {
        return getRuntime().newBoolean(field.isEnumConstant());
    }

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

    @JRubyMethod(name = "type")
    public IRubyObject field_type() {
        return JavaClass.get(getRuntime(), field.getType());
    }

    @JRubyMethod
    public IRubyObject value(ThreadContext context, IRubyObject object) {
        final Ruby runtime = context.runtime;

        final Object javaObject;
        if ( ! Modifier.isStatic( field.getModifiers() ) ) {
            javaObject = unwrapJavaObject(object);
        }
        else {
            javaObject = null;
        }

        try {
            return convertToRuby(runtime, field.get(javaObject));
        }
        catch (IllegalAccessException iae) {
            throw runtime.newTypeError("illegal access");
        }
    }

    @JRubyMethod
    public IRubyObject set_value(IRubyObject object, IRubyObject value) {
        final Object javaObject;
        if ( ! Modifier.isStatic( field.getModifiers() ) ) {
            javaObject = unwrapJavaObject(object);
        }
        else {
            javaObject = null;
        }

        final Object javaValue = convertValueToJava(value);
        try {
            field.set(javaObject, javaValue);
        }
        catch (IllegalAccessException iae) {
            throw getRuntime().newTypeError("illegal access on setting variable: " + iae.getMessage());
        }
        catch (IllegalArgumentException iae) {
            throw getRuntime().newTypeError("wrong type for " + field.getType().getName() + ": " +
                    ( javaValue == null ? null : javaValue.getClass().getName() ) );
        }
        return value;
    }

    @JRubyMethod(name = "final?")
    public RubyBoolean final_p() {
        return getRuntime().newBoolean(Modifier.isFinal(field.getModifiers()));
    }

    @JRubyMethod
    public IRubyObject static_value() {
        try {
            return convertToRuby( getRuntime(), field.get(null) );
        }
        catch (IllegalAccessException iae) {
            throw getRuntime().newTypeError("illegal static value access: " + iae.getMessage());
        }
    }

    @JRubyMethod
    public IRubyObject set_static_value(IRubyObject value) {
        if ( ! ( value instanceof JavaObject ) ) {
            throw getRuntime().newTypeError("not a java object:" + value);
        }
        final Object javaValue = convertValueToJava(value);
        try {
            field.set(null, javaValue);
        }
        catch (IllegalAccessException iae) {
            throw getRuntime().newTypeError(
                                "illegal access on setting static variable: " + iae.getMessage());
        }
        catch (IllegalArgumentException iae) {
            throw getRuntime().newTypeError("wrong type for " + field.getType().getName() + ": " +
                    ( javaValue == null ? null : javaValue.getClass().getName() ) );
        }
        return value;
    }

    @JRubyMethod
    public RubyString name() {
        return getRuntime().newString(field.getName());
    }

    @Override
    public AccessibleObject accessibleObject() {
        return field;
    }

    private Object unwrapJavaObject(final IRubyObject object) throws RaiseException {
        Object javaObject = JavaUtil.unwrapJavaValue(object);
        if ( javaObject == null ) {
            throw getRuntime().newTypeError("not a java object: " + object);
        }
        return javaObject;
    }

    private Object convertValueToJava(IRubyObject value) {
        Object val = value.dataGetStruct();
        if ( val instanceof JavaObject ) value = (IRubyObject) val;
        return value.toJava( field.getType() );
    }

    private static IRubyObject convertToRuby(final Ruby runtime, final Object javaValue) {
        return JavaUtil.convertJavaToUsableRubyObject(runtime, javaValue);
    }

}