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* Copyright (C) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
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* modification, are permitted provided that the following conditions are
* met:
*
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* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
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*
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*/

#include "config.h"

#include "V8NPObject.h"

#include "HTMLPlugInElement.h"
#include "NPV8Object.h"
#include "V8Binding.h"
#include "V8HTMLAppletElement.h"
#include "V8HTMLEmbedElement.h"
#include "V8HTMLObjectElement.h"
#include "V8NPUtils.h"
#include "V8ObjectConstructor.h"
#include "npruntime_impl.h"
#include "npruntime_priv.h"
#include <wtf/OwnArrayPtr.h>

namespace WebCore {

enum InvokeFunctionType {
    InvokeMethod = 1,
    InvokeConstruct = 2,
    InvokeDefault = 3
};

struct IdentifierRep {
    int number() const { return m_isString ? 0 : m_value.m_number; }
    const char* string() const { return m_isString ? m_value.m_string : 0; }

    union {
        const char* m_string;
        int m_number;
    } m_value;
    bool m_isString;
};

// FIXME: need comments.
// Params: holder could be HTMLEmbedElement or NPObject
static v8::Handle<v8::Value> npObjectInvokeImpl(const v8::Arguments& args, InvokeFunctionType functionId)
{
    NPObject* npObject;

    WrapperWorldType currentWorldType = worldType(args.GetIsolate());
    // These three types are subtypes of HTMLPlugInElement.
    if (V8HTMLAppletElement::HasInstance(args.Holder(), args.GetIsolate(), currentWorldType) || V8HTMLEmbedElement::HasInstance(args.Holder(), args.GetIsolate(), currentWorldType)
        || V8HTMLObjectElement::HasInstance(args.Holder(), args.GetIsolate(), currentWorldType)) {
        // The holder object is a subtype of HTMLPlugInElement.
        HTMLPlugInElement* element;
        if (V8HTMLAppletElement::HasInstance(args.Holder(), args.GetIsolate(), currentWorldType))
            element = V8HTMLAppletElement::toNative(args.Holder());
        else if (V8HTMLEmbedElement::HasInstance(args.Holder(), args.GetIsolate(), currentWorldType))
            element = V8HTMLEmbedElement::toNative(args.Holder());
        else
            element = V8HTMLObjectElement::toNative(args.Holder());
        ScriptInstance scriptInstance = element->getInstance();
        if (scriptInstance)
            npObject = v8ObjectToNPObject(scriptInstance->instance());
        else
            npObject = 0;
    } else {
        // The holder object is not a subtype of HTMLPlugInElement, it must be an NPObject which has three
        // internal fields.
        if (args.Holder()->InternalFieldCount() != npObjectInternalFieldCount)
            return throwError(v8ReferenceError, "NPMethod called on non-NPObject", args.GetIsolate());

        npObject = v8ObjectToNPObject(args.Holder());
    }

    // Verify that our wrapper wasn't using a NPObject which has already been deleted.
    if (!npObject || !_NPN_IsAlive(npObject))
        return throwError(v8ReferenceError, "NPObject deleted", args.GetIsolate());

    // Wrap up parameters.
    int numArgs = args.Length();
    OwnArrayPtr<NPVariant> npArgs = adoptArrayPtr(new NPVariant[numArgs]);

    for (int i = 0; i < numArgs; i++)
        convertV8ObjectToNPVariant(args[i], npObject, &npArgs[i]);

    NPVariant result;
    VOID_TO_NPVARIANT(result);

    bool retval = true;
    switch (functionId) {
    case InvokeMethod:
        if (npObject->_class->invoke) {
            v8::Handle<v8::String> functionName(v8::String::Cast(*args.Data()));
            NPIdentifier identifier = getStringIdentifier(functionName);
            retval = npObject->_class->invoke(npObject, identifier, npArgs.get(), numArgs, &result);
        }
        break;
    case InvokeConstruct:
        if (npObject->_class->construct)
            retval = npObject->_class->construct(npObject, npArgs.get(), numArgs, &result);
        break;
    case InvokeDefault:
        if (npObject->_class->invokeDefault)
            retval = npObject->_class->invokeDefault(npObject, npArgs.get(), numArgs, &result);
        break;
    default:
        break;
    }

    if (!retval)
        throwError(v8GeneralError, "Error calling method on NPObject.", args.GetIsolate());

    for (int i = 0; i < numArgs; i++)
        _NPN_ReleaseVariantValue(&npArgs[i]);

    // Unwrap return values.
    v8::Handle<v8::Value> returnValue;
    if (_NPN_IsAlive(npObject))
        returnValue = convertNPVariantToV8Object(&result, npObject, args.GetIsolate());
    _NPN_ReleaseVariantValue(&result);

    return returnValue;
}


v8::Handle<v8::Value> npObjectMethodHandler(const v8::Arguments& args)
{
    return npObjectInvokeImpl(args, InvokeMethod);
}


v8::Handle<v8::Value> npObjectInvokeDefaultHandler(const v8::Arguments& args)
{
    if (args.IsConstructCall())
        return npObjectInvokeImpl(args, InvokeConstruct);

    return npObjectInvokeImpl(args, InvokeDefault);
}


class V8NPTemplateMap
{
public:
    // NPIdentifier is PrivateIdentifier*.
    typedef HashMap<PrivateIdentifier*, v8::Persistent<v8::FunctionTemplate> > MapType;

    v8::Persistent<v8::FunctionTemplate> get(PrivateIdentifier* key)
    {
        return m_map.get(key);
    }

    void set(PrivateIdentifier* key, v8::Persistent<v8::FunctionTemplate> wrapper)
    {
        ASSERT(!m_map.contains(key));
        m_map.set(key, wrapper);
        wrapper.MakeWeak(m_isolate, key, weakCallback);
    }

    static V8NPTemplateMap& sharedInstance(v8::Isolate* isolate)
    {
        DEFINE_STATIC_LOCAL(V8NPTemplateMap, map, (isolate));
        ASSERT(isolate == map.m_isolate);
        return map;
    }

private:
    explicit V8NPTemplateMap(v8::Isolate* isolate)
        : m_isolate(isolate)
    {
    }

    static void weakCallback(v8::Isolate* isolate, v8::Persistent<v8::Value> object, void* context)
    {
        sharedInstance(isolate).dispose(static_cast<PrivateIdentifier*>(context));
    }

    void dispose(PrivateIdentifier* key)
    {
        MapType::iterator it = m_map.find(key);
        ASSERT(it != m_map.end());
        it->value.Dispose(m_isolate);
        it->value.Clear();
        m_map.remove(it);
    }

    MapType m_map;
    v8::Isolate* m_isolate;
};

static v8::Handle<v8::Value> npObjectGetProperty(v8::Local<v8::Object> self, NPIdentifier identifier, v8::Local<v8::Value> key, v8::Isolate* isolate)
{
    NPObject* npObject = v8ObjectToNPObject(self);

    // Verify that our wrapper wasn't using a NPObject which
    // has already been deleted.
    if (!npObject || !_NPN_IsAlive(npObject))
        return throwError(v8ReferenceError, "NPObject deleted", isolate);


    if (npObject->_class->hasProperty && npObject->_class->getProperty && npObject->_class->hasProperty(npObject, identifier)) {
        if (!_NPN_IsAlive(npObject))
            return throwError(v8ReferenceError, "NPObject deleted", isolate);

        NPVariant result;
        VOID_TO_NPVARIANT(result);
        if (!npObject->_class->getProperty(npObject, identifier, &result))
            return v8Undefined();

        v8::Handle<v8::Value> returnValue;
        if (_NPN_IsAlive(npObject))
            returnValue = convertNPVariantToV8Object(&result, npObject, isolate);
        _NPN_ReleaseVariantValue(&result);
        return returnValue;

    }

    if (!_NPN_IsAlive(npObject))
        return throwError(v8ReferenceError, "NPObject deleted", isolate);

    if (key->IsString() && npObject->_class->hasMethod && npObject->_class->hasMethod(npObject, identifier)) {
        if (!_NPN_IsAlive(npObject))
            return throwError(v8ReferenceError, "NPObject deleted", isolate);

        PrivateIdentifier* id = static_cast<PrivateIdentifier*>(identifier);
        v8::Persistent<v8::FunctionTemplate> functionTemplate = V8NPTemplateMap::sharedInstance(isolate).get(id);
        // Cache templates using identifier as the key.
        if (functionTemplate.IsEmpty()) {
            // Create a new template.
            v8::Local<v8::FunctionTemplate> temp = v8::FunctionTemplate::New();
            temp->SetCallHandler(npObjectMethodHandler, key);
            functionTemplate = v8::Persistent<v8::FunctionTemplate>::New(isolate, temp);
            V8NPTemplateMap::sharedInstance(isolate).set(id, functionTemplate);
        }

        // FunctionTemplate caches function for each context.
        v8::Local<v8::Function> v8Function = functionTemplate->GetFunction();
        v8Function->SetName(v8::Handle<v8::String>::Cast(key));
        return v8Function;
    }

    return v8Undefined();
}

v8::Handle<v8::Value> npObjectNamedPropertyGetter(v8::Local<v8::String> name, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = getStringIdentifier(name);
    return npObjectGetProperty(info.Holder(), identifier, name, info.GetIsolate());
}

v8::Handle<v8::Value> npObjectIndexedPropertyGetter(uint32_t index, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = _NPN_GetIntIdentifier(index);
    return npObjectGetProperty(info.Holder(), identifier, v8::Number::New(index), info.GetIsolate());
}

v8::Handle<v8::Value> npObjectGetNamedProperty(v8::Local<v8::Object> self, v8::Local<v8::String> name, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = getStringIdentifier(name);
    return npObjectGetProperty(self, identifier, name, info.GetIsolate());
}

v8::Handle<v8::Value> npObjectGetIndexedProperty(v8::Local<v8::Object> self, uint32_t index, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = _NPN_GetIntIdentifier(index);
    return npObjectGetProperty(self, identifier, v8::Number::New(index), info.GetIsolate());
}

v8::Handle<v8::Integer> npObjectQueryProperty(v8::Local<v8::String> name, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = getStringIdentifier(name);
    return npObjectGetProperty(info.Holder(), identifier, name, info.GetIsolate()).IsEmpty() ? v8::Handle<v8::Integer>() : v8Integer(0, info.GetIsolate());
}

static v8::Handle<v8::Value> npObjectSetProperty(v8::Local<v8::Object> self, NPIdentifier identifier, v8::Local<v8::Value> value, v8::Isolate* isolate)
{
    NPObject* npObject = v8ObjectToNPObject(self);

    // Verify that our wrapper wasn't using a NPObject which has already been deleted.
    if (!npObject || !_NPN_IsAlive(npObject)) {
        throwError(v8ReferenceError, "NPObject deleted", isolate);
        return value;  // Intercepted, but an exception was thrown.
    }

    if (npObject->_class->hasProperty && npObject->_class->setProperty && npObject->_class->hasProperty(npObject, identifier)) {
        if (!_NPN_IsAlive(npObject))
            return throwError(v8ReferenceError, "NPObject deleted", isolate);

        NPVariant npValue;
        VOID_TO_NPVARIANT(npValue);
        convertV8ObjectToNPVariant(value, npObject, &npValue);
        bool success = npObject->_class->setProperty(npObject, identifier, &npValue);
        _NPN_ReleaseVariantValue(&npValue);
        if (success)
            return value; // Intercept the call.
    }
    return v8Undefined();
}


v8::Handle<v8::Value> npObjectNamedPropertySetter(v8::Local<v8::String> name, v8::Local<v8::Value> value, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = getStringIdentifier(name);
    return npObjectSetProperty(info.Holder(), identifier, value, info.GetIsolate());
}


v8::Handle<v8::Value> npObjectIndexedPropertySetter(uint32_t index, v8::Local<v8::Value> value, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = _NPN_GetIntIdentifier(index);
    return npObjectSetProperty(info.Holder(), identifier, value, info.GetIsolate());
}

v8::Handle<v8::Value> npObjectSetNamedProperty(v8::Local<v8::Object> self, v8::Local<v8::String> name, v8::Local<v8::Value> value, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = getStringIdentifier(name);
    return npObjectSetProperty(self, identifier, value, info.GetIsolate());
}

v8::Handle<v8::Value> npObjectSetIndexedProperty(v8::Local<v8::Object> self, uint32_t index, v8::Local<v8::Value> value, const v8::AccessorInfo& info)
{
    NPIdentifier identifier = _NPN_GetIntIdentifier(index);
    return npObjectSetProperty(self, identifier, value, info.GetIsolate());
}

v8::Handle<v8::Array> npObjectPropertyEnumerator(const v8::AccessorInfo& info, bool namedProperty)
{
    NPObject* npObject = v8ObjectToNPObject(info.Holder());

    // Verify that our wrapper wasn't using a NPObject which
    // has already been deleted.
    if (!npObject || !_NPN_IsAlive(npObject))
        throwError(v8ReferenceError, "NPObject deleted", info.GetIsolate());

    if (NP_CLASS_STRUCT_VERSION_HAS_ENUM(npObject->_class) && npObject->_class->enumerate) {
        uint32_t count;
        NPIdentifier* identifiers;
        if (npObject->_class->enumerate(npObject, &identifiers, &count)) {
            v8::Handle<v8::Array> properties = v8::Array::New(count);
            for (uint32_t i = 0; i < count; ++i) {
                IdentifierRep* identifier = static_cast<IdentifierRep*>(identifiers[i]);
                if (namedProperty)
                    properties->Set(v8Integer(i, info.GetIsolate()), v8::String::NewSymbol(identifier->string()));
                else
                    properties->Set(v8Integer(i, info.GetIsolate()), v8Integer(identifier->number(), info.GetIsolate()));
            }

            return properties;
        }
    }

    return v8::Handle<v8::Array>();
}

v8::Handle<v8::Array> npObjectNamedPropertyEnumerator(const v8::AccessorInfo& info)
{
    return npObjectPropertyEnumerator(info, true);
}

v8::Handle<v8::Array> npObjectIndexedPropertyEnumerator(const v8::AccessorInfo& info)
{
    return npObjectPropertyEnumerator(info, false);
}

static void weakNPObjectCallback(v8::Isolate*, v8::Persistent<v8::Value>, void*);

static DOMWrapperMap<NPObject>& staticNPObjectMap()
{
    DEFINE_STATIC_LOCAL(DOMWrapperMap<NPObject>, npObjectMap, (v8::Isolate::GetCurrent(), &weakNPObjectCallback));
    return npObjectMap;
}

static void weakNPObjectCallback(v8::Isolate* isolate, v8::Persistent<v8::Value> value, void*)
{
    ASSERT(value->IsObject());
    v8::Persistent<v8::Object> wrapper = v8::Persistent<v8::Object>::Cast(value);
    NPObject* npObject = static_cast<NPObject*>(toNative(wrapper));

    ASSERT(npObject);
    ASSERT(staticNPObjectMap().get(npObject) == wrapper);

    // Must remove from our map before calling _NPN_ReleaseObject(). _NPN_ReleaseObject can
    // call forgetV8ObjectForNPObject, which uses the table as well.
    staticNPObjectMap().removeAndDispose(npObject, wrapper, isolate);

    if (_NPN_IsAlive(npObject))
        _NPN_ReleaseObject(npObject);
}

v8::Local<v8::Object> createV8ObjectForNPObject(NPObject* object, NPObject* root)
{
    static v8::Persistent<v8::FunctionTemplate> npObjectDesc;

    ASSERT(v8::Context::InContext());

    // If this is a v8 object, just return it.
    if (object->_class == npScriptObjectClass) {
        V8NPObject* v8NPObject = reinterpret_cast<V8NPObject*>(object);
        return v8::Local<v8::Object>::New(v8NPObject->v8Object);
    }

    // If we've already wrapped this object, just return it.
    v8::Handle<v8::Object> wrapper = staticNPObjectMap().get(object);
    if (!wrapper.IsEmpty())
        return v8::Local<v8::Object>::New(wrapper);

    // FIXME: we should create a Wrapper type as a subclass of JSObject. It has two internal fields, field 0 is the wrapped
    // pointer, and field 1 is the type. There should be an api function that returns unused type id. The same Wrapper type
    // can be used by DOM bindings.
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    if (npObjectDesc.IsEmpty()) {
        npObjectDesc = v8::Persistent<v8::FunctionTemplate>::New(isolate, v8::FunctionTemplate::New());
        npObjectDesc->InstanceTemplate()->SetInternalFieldCount(npObjectInternalFieldCount);
        npObjectDesc->InstanceTemplate()->SetNamedPropertyHandler(npObjectNamedPropertyGetter, npObjectNamedPropertySetter, npObjectQueryProperty, 0, npObjectNamedPropertyEnumerator);
        npObjectDesc->InstanceTemplate()->SetIndexedPropertyHandler(npObjectIndexedPropertyGetter, npObjectIndexedPropertySetter, 0, 0, npObjectIndexedPropertyEnumerator);
        npObjectDesc->InstanceTemplate()->SetCallAsFunctionHandler(npObjectInvokeDefaultHandler);
    }

    // FIXME: Move staticNPObjectMap() to DOMDataStore.
    // Use V8DOMWrapper::createWrapper() and
    // V8DOMWrapper::associateObjectWithWrapper()
    // to create a wrapper object.
    v8::Handle<v8::Function> v8Function = npObjectDesc->GetFunction();
    v8::Local<v8::Object> value = V8ObjectConstructor::newInstance(v8Function);
    if (value.IsEmpty())
        return value;

    V8DOMWrapper::setNativeInfo(value, npObjectTypeInfo(), object);

    // KJS retains the object as part of its wrapper (see Bindings::CInstance).
    _NPN_RetainObject(object);
    _NPN_RegisterObject(object, root);

    WrapperConfiguration configuration = buildWrapperConfiguration(object, WrapperConfiguration::Dependent);
    staticNPObjectMap().set(object, value, configuration);
    ASSERT(V8DOMWrapper::maybeDOMWrapper(value));
    return value;
}

void forgetV8ObjectForNPObject(NPObject* object)
{
    v8::Handle<v8::Object> wrapper = staticNPObjectMap().get(object);
    if (!wrapper.IsEmpty()) {
        v8::HandleScope scope;
        V8DOMWrapper::clearNativeInfo(wrapper, npObjectTypeInfo());
        staticNPObjectMap().removeAndDispose(object, wrapper, v8::Isolate::GetCurrent());
        _NPN_ReleaseObject(object);
    }
}

} // namespace WebCore