/*
 * Copyright (c) 2011, 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 "bindings/v8/ScriptProfiler.h"

#include "bindings/core/v8/V8Node.h"
#include "bindings/core/v8/V8Window.h"
#include "bindings/v8/RetainedDOMInfo.h"
#include "bindings/v8/ScriptValue.h"
#include "bindings/v8/V8Binding.h"
#include "bindings/v8/WrapperTypeInfo.h"
#include "core/dom/Document.h"
#include "core/inspector/BindingVisitors.h"

#include <v8-profiler.h>
#include <v8.h>

#include "wtf/ThreadSpecific.h"

namespace WebCore {

typedef HashMap<String, double> ProfileNameIdleTimeMap;

void ScriptProfiler::setSamplingInterval(int intervalUs)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::CpuProfiler* profiler = isolate->GetCpuProfiler();
    if (profiler)
        profiler->SetSamplingInterval(intervalUs);
}

void ScriptProfiler::start(const String& title)
{
    ProfileNameIdleTimeMap* profileNameIdleTimeMap = ScriptProfiler::currentProfileNameIdleTimeMap();
    if (profileNameIdleTimeMap->contains(title))
        return;
    profileNameIdleTimeMap->add(title, 0);

    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::CpuProfiler* profiler = isolate->GetCpuProfiler();
    if (!profiler)
        return;
    v8::HandleScope handleScope(isolate);
    profiler->StartProfiling(v8String(isolate, title), true);
}

PassRefPtrWillBeRawPtr<ScriptProfile> ScriptProfiler::stop(const String& title)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::CpuProfiler* profiler = isolate->GetCpuProfiler();
    if (!profiler)
        return nullptr;
    v8::HandleScope handleScope(isolate);
    v8::CpuProfile* profile = profiler->StopProfiling(v8String(isolate, title));
    if (!profile)
        return nullptr;

    String profileTitle = toCoreString(profile->GetTitle());
    double idleTime = 0.0;
    ProfileNameIdleTimeMap* profileNameIdleTimeMap = ScriptProfiler::currentProfileNameIdleTimeMap();
    ProfileNameIdleTimeMap::iterator profileIdleTime = profileNameIdleTimeMap->find(profileTitle);
    if (profileIdleTime != profileNameIdleTimeMap->end()) {
        idleTime = profileIdleTime->value * 1000.0;
        profileNameIdleTimeMap->remove(profileIdleTime);
    }

    return ScriptProfile::create(profile, idleTime);
}

void ScriptProfiler::collectGarbage()
{
    v8::V8::LowMemoryNotification();
}

ScriptValue ScriptProfiler::objectByHeapObjectId(unsigned id)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HeapProfiler* profiler = isolate->GetHeapProfiler();
    v8::HandleScope handleScope(isolate);
    v8::Handle<v8::Value> value = profiler->FindObjectById(id);
    if (value.IsEmpty() || !value->IsObject())
        return ScriptValue();

    v8::Handle<v8::Object> object = value.As<v8::Object>();

    if (object->InternalFieldCount() >= v8DefaultWrapperInternalFieldCount) {
        v8::Handle<v8::Value> wrapper = object->GetInternalField(v8DOMWrapperObjectIndex);
        // Skip wrapper boilerplates which are like regular wrappers but don't have
        // native object.
        if (!wrapper.IsEmpty() && wrapper->IsUndefined())
            return ScriptValue();
    }

    ScriptState* scriptState = ScriptState::from(object->CreationContext());
    return ScriptValue(scriptState, object);
}

unsigned ScriptProfiler::getHeapObjectId(const ScriptValue& value)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HeapProfiler* profiler = isolate->GetHeapProfiler();
    v8::SnapshotObjectId id = profiler->GetObjectId(value.v8Value());
    return id;
}

void ScriptProfiler::clearHeapObjectIds()
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HeapProfiler* profiler = isolate->GetHeapProfiler();
    profiler->ClearObjectIds();
}

namespace {

class ActivityControlAdapter FINAL : public v8::ActivityControl {
public:
    ActivityControlAdapter(ScriptProfiler::HeapSnapshotProgress* progress)
            : m_progress(progress), m_firstReport(true) { }
    virtual ControlOption ReportProgressValue(int done, int total) OVERRIDE
    {
        ControlOption result = m_progress->isCanceled() ? kAbort : kContinue;
        if (m_firstReport) {
            m_firstReport = false;
            m_progress->Start(total);
        } else
            m_progress->Worked(done);
        if (done >= total)
            m_progress->Done();
        return result;
    }
private:
    ScriptProfiler::HeapSnapshotProgress* m_progress;
    bool m_firstReport;
};

class GlobalObjectNameResolver FINAL : public v8::HeapProfiler::ObjectNameResolver {
public:
    virtual const char* GetName(v8::Handle<v8::Object> object) OVERRIDE
    {
        LocalDOMWindow* window = toDOMWindow(object, v8::Isolate::GetCurrent());
        if (!window)
            return 0;
        CString url = window->document()->url().string().utf8();
        m_strings.append(url);
        return url.data();
    }

private:
    Vector<CString> m_strings;
};

} // namespace

void ScriptProfiler::startTrackingHeapObjects(bool trackAllocations)
{
    v8::Isolate::GetCurrent()->GetHeapProfiler()->StartTrackingHeapObjects(trackAllocations);
}

namespace {

class HeapStatsStream : public v8::OutputStream {
public:
    HeapStatsStream(ScriptProfiler::OutputStream* stream) : m_stream(stream) { }
    virtual void EndOfStream() OVERRIDE { }

    virtual WriteResult WriteAsciiChunk(char* data, int size) OVERRIDE
    {
        ASSERT(false);
        return kAbort;
    }

    virtual WriteResult WriteHeapStatsChunk(v8::HeapStatsUpdate* updateData, int count) OVERRIDE
    {
        Vector<uint32_t> rawData(count * 3);
        for (int i = 0; i < count; ++i) {
            int offset = i * 3;
            rawData[offset] = updateData[i].index;
            rawData[offset + 1] = updateData[i].count;
            rawData[offset + 2] = updateData[i].size;
        }
        m_stream->write(rawData.data(), rawData.size());
        return kContinue;
    }

private:
    ScriptProfiler::OutputStream* m_stream;
};

}

unsigned ScriptProfiler::requestHeapStatsUpdate(ScriptProfiler::OutputStream* stream)
{
    HeapStatsStream heapStatsStream(stream);
    return v8::Isolate::GetCurrent()->GetHeapProfiler()->GetHeapStats(&heapStatsStream);
}

void ScriptProfiler::stopTrackingHeapObjects()
{
    v8::Isolate::GetCurrent()->GetHeapProfiler()->StopTrackingHeapObjects();
}

// FIXME: This method should receive a ScriptState, from which we should retrieve an Isolate.
PassRefPtr<ScriptHeapSnapshot> ScriptProfiler::takeHeapSnapshot(const String& title, HeapSnapshotProgress* control)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HeapProfiler* profiler = isolate->GetHeapProfiler();
    if (!profiler)
        return nullptr;
    v8::HandleScope handleScope(isolate);
    ASSERT(control);
    ActivityControlAdapter adapter(control);
    GlobalObjectNameResolver resolver;
    const v8::HeapSnapshot* snapshot = profiler->TakeHeapSnapshot(v8String(isolate, title), &adapter, &resolver);
    return snapshot ? ScriptHeapSnapshot::create(snapshot) : nullptr;
}

static v8::RetainedObjectInfo* retainedDOMInfo(uint16_t classId, v8::Handle<v8::Value> wrapper)
{
    ASSERT(classId == v8DOMNodeClassId);
    if (!wrapper->IsObject())
        return 0;
    Node* node = V8Node::toNative(wrapper.As<v8::Object>());
    return node ? new RetainedDOMInfo(node) : 0;
}

void ScriptProfiler::initialize()
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HeapProfiler* profiler = isolate->GetHeapProfiler();
    if (profiler)
        profiler->SetWrapperClassInfoProvider(v8DOMNodeClassId, &retainedDOMInfo);
}

void ScriptProfiler::visitNodeWrappers(WrappedNodeVisitor* visitor)
{
    // visitNodeWrappers() should receive a ScriptState and retrieve an Isolate
    // from the ScriptState.
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    v8::HandleScope handleScope(isolate);

    class DOMNodeWrapperVisitor : public v8::PersistentHandleVisitor {
    public:
        DOMNodeWrapperVisitor(WrappedNodeVisitor* visitor, v8::Isolate* isolate)
            : m_visitor(visitor)
            , m_isolate(isolate)
        {
        }

        virtual void VisitPersistentHandle(v8::Persistent<v8::Value>* value, uint16_t classId) OVERRIDE
        {
            if (classId != v8DOMNodeClassId)
                return;
            // Casting to Handle is safe here, since the Persistent cannot get
            // GCd during visiting.
            v8::Handle<v8::Object>* wrapper = reinterpret_cast<v8::Handle<v8::Object>*>(value);
            ASSERT_UNUSED(m_isolate, V8Node::hasInstance(*wrapper, m_isolate));
            ASSERT((*wrapper)->IsObject());
            m_visitor->visitNode(V8Node::toNative(*wrapper));
        }

    private:
        WrappedNodeVisitor* m_visitor;
        v8::Isolate* m_isolate;
    } wrapperVisitor(visitor, isolate);

    v8::V8::VisitHandlesWithClassIds(&wrapperVisitor);
}

ProfileNameIdleTimeMap* ScriptProfiler::currentProfileNameIdleTimeMap()
{
    AtomicallyInitializedStatic(WTF::ThreadSpecific<ProfileNameIdleTimeMap>*, map = new WTF::ThreadSpecific<ProfileNameIdleTimeMap>);
    return *map;
}

void ScriptProfiler::setIdle(bool isIdle)
{
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    if (v8::CpuProfiler* profiler = isolate->GetCpuProfiler())
        profiler->SetIdle(isIdle);
}

} // namespace WebCore