/*
 * Copyright (C) 2007-2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "V8InjectedScriptHost.h"

#include "DOMWindow.h"
#include "Database.h"
#include "Frame.h"
#include "InjectedScript.h"
#include "InjectedScriptHost.h"
#include "InspectorValues.h"
#include "Node.h"
#include "Page.h"
#include "ScriptDebugServer.h"
#include "ScriptValue.h"

#include "V8Binding.h"
#include "V8BindingState.h"
#include "V8DOMWindow.h"
#include "V8Database.h"
#include "V8HiddenPropertyName.h"
#include "V8JavaScriptCallFrame.h"
#include "V8Node.h"
#include "V8Proxy.h"
#include "V8Storage.h"
#include <wtf/RefPtr.h>

namespace WebCore {

Node* InjectedScriptHost::scriptValueAsNode(ScriptValue value)
{
    if (!value.isObject() || value.isNull())
        return 0;
    return V8Node::toNative(v8::Handle<v8::Object>::Cast(value.v8Value()));
}

ScriptValue InjectedScriptHost::nodeAsScriptValue(ScriptState* state, Node* node)
{
    v8::HandleScope scope;
    v8::Local<v8::Context> context = state->context();
    v8::Context::Scope contextScope(context);

    return ScriptValue(toV8(node));
}

static void WeakReferenceCallback(v8::Persistent<v8::Value> object, void* parameter)
{
    InjectedScriptHost* nativeObject = static_cast<InjectedScriptHost*>(parameter);
    nativeObject->deref();
    object.Dispose();
}

static v8::Local<v8::Object> createInjectedScriptHostV8Wrapper(InjectedScriptHost* host)
{
    v8::Local<v8::Function> function = V8InjectedScriptHost::GetTemplate()->GetFunction();
    if (function.IsEmpty()) {
        // Return if allocation failed.
        return v8::Local<v8::Object>();
    }
    v8::Local<v8::Object> instance = SafeAllocation::newInstance(function);
    if (instance.IsEmpty()) {
        // Avoid setting the wrapper if allocation failed.
        return v8::Local<v8::Object>();
    }
    V8DOMWrapper::setDOMWrapper(instance, &V8InjectedScriptHost::info, host);
    // Create a weak reference to the v8 wrapper of InspectorBackend to deref
    // InspectorBackend when the wrapper is garbage collected.
    host->ref();
    v8::Persistent<v8::Object> weakHandle = v8::Persistent<v8::Object>::New(instance);
    weakHandle.MakeWeak(host, &WeakReferenceCallback);
    return instance;
}

ScriptObject InjectedScriptHost::createInjectedScript(const String& scriptSource, ScriptState* inspectedScriptState, long id)
{
    v8::HandleScope scope;

    v8::Local<v8::Context> inspectedContext = inspectedScriptState->context();
    v8::Context::Scope contextScope(inspectedContext);

    // Call custom code to create InjectedScripHost wrapper specific for the context
    // instead of calling toV8() that would create the
    // wrapper in the current context.
    // FIXME: make it possible to use generic bindings factory for InjectedScriptHost.
    v8::Local<v8::Object> scriptHostWrapper = createInjectedScriptHostV8Wrapper(this);
    if (scriptHostWrapper.IsEmpty())
        return ScriptObject();

    v8::Local<v8::Object> windowGlobal = inspectedContext->Global();

    // Inject javascript into the context. The compiled script is supposed to evaluate into
    // a single anonymous function(it's anonymous to avoid cluttering the global object with
    // inspector's stuff) the function is called a few lines below with InjectedScriptHost wrapper,
    // injected script id and explicit reference to the inspected global object. The function is expected
    // to create and configure InjectedScript instance that is going to be used by the inspector.
    v8::Local<v8::Script> script = v8::Script::Compile(v8String(scriptSource));
    v8::Local<v8::Value> v = script->Run();
    ASSERT(!v.IsEmpty());
    ASSERT(v->IsFunction());

    v8::Handle<v8::Value> args[] = {
      scriptHostWrapper,
      windowGlobal,
      v8::Number::New(id),
    };
    v8::Local<v8::Value> injectedScriptValue = v8::Function::Cast(*v)->Call(windowGlobal, 3, args);
    v8::Local<v8::Object> injectedScript(v8::Object::Cast(*injectedScriptValue));
    return ScriptObject(inspectedScriptState, injectedScript);
}

void InjectedScriptHost::discardInjectedScript(ScriptState* inspectedScriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = inspectedScriptState->context();
    v8::Context::Scope contextScope(context);

    v8::Local<v8::Object> global = context->Global();
    // Skip proxy object. The proxy object will survive page navigation while we need
    // an object whose lifetime consides with that of the inspected context.
    global = v8::Local<v8::Object>::Cast(global->GetPrototype());

    v8::Handle<v8::String> key = V8HiddenPropertyName::devtoolsInjectedScript();
    global->DeleteHiddenValue(key);
}

v8::Handle<v8::Value> V8InjectedScriptHost::inspectedNodeCallback(const v8::Arguments& args)
{
    INC_STATS("InjectedScriptHost.inspectedNode()");
    if (args.Length() < 1)
        return v8::Undefined();

    InjectedScriptHost* host = V8InjectedScriptHost::toNative(args.Holder());
    
    Node* node = host->inspectedNode(args[0]->ToInt32()->Value());
    if (!node)
        return v8::Undefined();

    return toV8(node);
}

v8::Handle<v8::Value> V8InjectedScriptHost::internalConstructorNameCallback(const v8::Arguments& args)
{
    INC_STATS("InjectedScriptHost.internalConstructorName()");
    if (args.Length() < 1)
        return v8::Undefined();

    if (!args[0]->IsObject())
        return v8::Undefined();

    return args[0]->ToObject()->GetConstructorName();
}

v8::Handle<v8::Value> V8InjectedScriptHost::inspectCallback(const v8::Arguments& args)
{
    INC_STATS("InjectedScriptHost.inspect()");
    if (args.Length() < 2)
        return v8::Undefined();

    InjectedScriptHost* host = V8InjectedScriptHost::toNative(args.Holder());
    ScriptValue objectId(args[0]);
    ScriptValue hints(args[1]);
    host->inspectImpl(objectId.toInspectorValue(ScriptState::current()), hints.toInspectorValue(ScriptState::current()));

    return v8::Undefined();
}

v8::Handle<v8::Value> V8InjectedScriptHost::currentCallFrameCallback(const v8::Arguments& args)
{
#if ENABLE(JAVASCRIPT_DEBUGGER)
    INC_STATS("InjectedScriptHost.currentCallFrame()");
    return toV8(ScriptDebugServer::shared().currentCallFrame());
#else
    UNUSED_PARAM(args);
    return v8::Undefined();
#endif
}

v8::Handle<v8::Value> V8InjectedScriptHost::databaseIdCallback(const v8::Arguments& args)
{
    INC_STATS("InjectedScriptHost.databaseId()");
    if (args.Length() < 1)
        return v8::Undefined();
#if ENABLE(DATABASE)
    InjectedScriptHost* host = V8InjectedScriptHost::toNative(args.Holder());
    Database* database = V8Database::toNative(v8::Handle<v8::Object>::Cast(args[0]));
    if (database)
        return v8::Number::New(host->databaseIdImpl(database));
#endif
    return v8::Undefined();
}

v8::Handle<v8::Value> V8InjectedScriptHost::storageIdCallback(const v8::Arguments& args)
{
    if (args.Length() < 1)
        return v8::Undefined();
#if ENABLE(DOM_STORAGE)
    INC_STATS("InjectedScriptHost.storageId()");
    InjectedScriptHost* host = V8InjectedScriptHost::toNative(args.Holder());
    Storage* storage = V8Storage::toNative(v8::Handle<v8::Object>::Cast(args[0]));
    if (storage)
        return v8::Number::New(host->storageIdImpl(storage));
#endif
    return v8::Undefined();
}

InjectedScript InjectedScriptHost::injectedScriptFor(ScriptState* inspectedScriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = inspectedScriptState->context();
    v8::Context::Scope contextScope(context);

    v8::Local<v8::Object> global = context->Global();
    // Skip proxy object. The proxy object will survive page navigation while we need
    // an object whose lifetime consides with that of the inspected context.
    global = v8::Local<v8::Object>::Cast(global->GetPrototype());

    v8::Handle<v8::String> key = V8HiddenPropertyName::devtoolsInjectedScript();
    v8::Local<v8::Value> val = global->GetHiddenValue(key);
    if (!val.IsEmpty() && val->IsObject())
        return InjectedScript(ScriptObject(inspectedScriptState, v8::Local<v8::Object>::Cast(val)));

    if (!canAccessInspectedWindow(inspectedScriptState))
        return InjectedScript();

    pair<long, ScriptObject> injectedScript = injectScript(injectedScriptSource(), inspectedScriptState);
    InjectedScript result(injectedScript.second);
    m_idToInjectedScript.set(injectedScript.first, result);
    global->SetHiddenValue(key, injectedScript.second.v8Object());
    return result;
}

bool InjectedScriptHost::canAccessInspectedWindow(ScriptState* scriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = scriptState->context();
    v8::Local<v8::Object> global = context->Global();
    if (global.IsEmpty())
        return false;
    v8::Handle<v8::Object> holder = V8DOMWrapper::lookupDOMWrapper(V8DOMWindow::GetTemplate(), global);
    if (holder.IsEmpty())
        return false;
    Frame* frame = V8DOMWindow::toNative(holder)->frame();

    v8::Context::Scope contextScope(context);
    return V8BindingSecurity::canAccessFrame(V8BindingState::Only(), frame, false);
}

} // namespace WebCore