package org.jruby.java.proxies;

import org.jruby.Ruby;
import org.jruby.RubyClass;
import org.jruby.RubyModule;
import org.jruby.internal.runtime.methods.DynamicMethod;
import org.jruby.javasupport.Java;
import org.jruby.runtime.Block;
import org.jruby.runtime.CallSite;
import org.jruby.runtime.MethodIndex;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.Visibility;
import org.jruby.runtime.builtin.IRubyObject;

public class ConcreteJavaProxy extends JavaProxy {
    public ConcreteJavaProxy(Ruby runtime, RubyClass klazz) {
        super(runtime, klazz);
    }
    
    public static RubyClass createConcreteJavaProxy(ThreadContext context) {
        Ruby runtime = context.getRuntime();
        
        RubyClass concreteJavaProxy = runtime.defineClass("ConcreteJavaProxy",
                runtime.getJavaSupport().getJavaProxyClass(),
                new ObjectAllocator() {
            public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
                return new ConcreteJavaProxy(runtime, klazz);
            }
        });
        initialize(concreteJavaProxy);
        return concreteJavaProxy;
    }

    protected static void initialize(RubyClass concreteJavaProxy) {
        concreteJavaProxy.addMethod("initialize", new org.jruby.internal.runtime.methods.JavaMethod(concreteJavaProxy, Visibility.PUBLIC) {
            private final CallSite jcreateSite = MethodIndex.getFunctionalCallSite("__jcreate!");
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args, Block block) {
                return jcreateSite.call(context, self, self, args, block);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, Block block) {
                return jcreateSite.call(context, self, self, block);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, Block block) {
                return jcreateSite.call(context, self, self, arg0, block);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, Block block) {
                return jcreateSite.call(context, self, self, arg0, arg1, block);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2, Block block) {
                return jcreateSite.call(context, self, self, arg0, arg1, arg2, block);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                return jcreateSite.call(context, self, self, args);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name) {
                return jcreateSite.call(context, self, self);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0) {
                return jcreateSite.call(context, self, self, arg0);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1) {
                return jcreateSite.call(context, self, self, arg0, arg1);
            }
            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2) {
                return jcreateSite.call(context, self, self, arg0, arg1, arg2);
            }
        });

        // We define a custom "new" method to ensure that __jcreate! is getting called,
        // so that if the user doesn't call super in their subclasses, the object will
        // still get set up properly. See JRUBY-4704.
        RubyClass singleton = concreteJavaProxy.getSingletonClass();
        final DynamicMethod oldNew = singleton.searchMethod("new");
        singleton.addMethod("new", new org.jruby.internal.runtime.methods.JavaMethod(singleton, Visibility.PUBLIC) {
            private final CallSite jcreateSite = MethodIndex.getFunctionalCallSite("__jcreate!");

            private boolean needsCreate(IRubyObject recv) {
                return ((JavaProxy)recv).object == null;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args, Block block) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", args, block);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, args, block);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, Block block) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", block);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, block);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, Block block) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0, block);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0, block);

                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, Block block) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0, arg1, block);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0, arg1, block);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2, Block block) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0, arg1, arg2, block);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0, arg1, arg2, block);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject[] args) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", args);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, args);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy");
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0, arg1);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0, arg1);
                return proxy;
            }

            @Override
            public IRubyObject call(ThreadContext context, IRubyObject self, RubyModule clazz, String name, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2) {
                IRubyObject proxy = oldNew.call(context, self, clazz, "new_proxy", arg0, arg1, arg2);
                if (needsCreate(proxy)) jcreateSite.call(context, proxy, proxy, arg0, arg1, arg2);
                return proxy;
            }
        });
    }

    // This alternate ivar logic is disabled because it can cause self-referencing
    // chains to keep the original object alive. See JRUBY-4832.
//    @Override
//    public Object getVariable(int index) {
//        return getRuntime().getJavaSupport().getJavaObjectVariable(this, index);
//    }
//
//    @Override
//    public void setVariable(int index, Object value) {
//        getRuntime().getJavaSupport().setJavaObjectVariable(this, index, value);
//    }

    /**
     * Because we can't physically associate an ID with a Java object, we can
     * only use the identity hashcode here.
     *
     * @return The identity hashcode for the Java object.
     */
    public IRubyObject id() {
        return getRuntime().newFixnum(System.identityHashCode(getObject()));
    }

    @Override
    public Object toJava(Class type) {
        Object obj = getObject();
        Class cls = obj.getClass();

        if (type.isPrimitive()) {
            if (obj instanceof Number && type != Boolean.TYPE ||
                    obj instanceof Character && type == Character.TYPE ||
                    obj instanceof Boolean && type == Boolean.TYPE) {
                // FIXME in more permissive call paths, like invokedynamic, this can allow
                // precision-loading downcasts to happen silently
                return obj;
            } else {
                throw getRuntime().newTypeError("failed to coerce " + cls.getName() + " to " + type.getName());
            }
        } else if (type.isAssignableFrom(cls)) {
            if (Java.OBJECT_PROXY_CACHE) {
                getRuntime().getJavaSupport().getObjectProxyCache().put(obj, this);
            }
            return obj;
        } else {
            return super.toJava(type);
        }
    }
}
