// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "config.h"
#include "bindings/core/v8/ScriptPromiseResolver.h"

#include "bindings/core/v8/V8RecursionScope.h"

namespace blink {

ScriptPromiseResolver::ScriptPromiseResolver(ScriptState* scriptState)
    : ActiveDOMObject(scriptState->executionContext())
    , m_state(Pending)
    , m_scriptState(scriptState)
    , m_mode(Default)
    , m_timer(this, &ScriptPromiseResolver::onTimerFired)
    , m_resolver(scriptState)
#if ENABLE(ASSERT)
    , m_isPromiseCalled(false)
#endif
{
    if (executionContext()->activeDOMObjectsAreStopped()) {
        m_state = ResolvedOrRejected;
        m_resolver.clear();
    }
}

void ScriptPromiseResolver::suspend()
{
    m_timer.stop();
}

void ScriptPromiseResolver::resume()
{
    if (m_state == Resolving || m_state == Rejecting)
        m_timer.startOneShot(0, FROM_HERE);
}

void ScriptPromiseResolver::stop()
{
    m_timer.stop();
    clear();
}

void ScriptPromiseResolver::keepAliveWhilePending()
{
    if (m_state == ResolvedOrRejected || m_mode == KeepAliveWhilePending)
        return;

    // Keep |this| while the promise is Pending.
    // deref() will be called in clear().
    m_mode = KeepAliveWhilePending;
    ref();
}

void ScriptPromiseResolver::onTimerFired(Timer<ScriptPromiseResolver>*)
{
    ASSERT(m_state == Resolving || m_state == Rejecting);
    ScriptState::Scope scope(m_scriptState.get());
    resolveOrRejectImmediately();
}

void ScriptPromiseResolver::resolveOrRejectImmediately()
{
    ASSERT(!executionContext()->activeDOMObjectsAreStopped());
    ASSERT(!executionContext()->activeDOMObjectsAreSuspended());
    {
        if (m_state == Resolving) {
            m_resolver.resolve(m_value.newLocal(m_scriptState->isolate()));
        } else {
            ASSERT(m_state == Rejecting);
            m_resolver.reject(m_value.newLocal(m_scriptState->isolate()));
        }
    }
    clear();
}

void ScriptPromiseResolver::clear()
{
    if (m_state == ResolvedOrRejected)
        return;
    ResolutionState state = m_state;
    m_state = ResolvedOrRejected;
    m_resolver.clear();
    m_value.clear();
    if (m_mode == KeepAliveWhilePending) {
        // |ref| was called in |keepAliveWhilePending|.
        deref();
    }
    // |this| may be deleted here, but it is safe to check |state| because
    // it doesn't depend on |this|. When |this| is deleted, |state| can't be
    // |Resolving| nor |Rejecting| and hence |this->deref()| can't be executed.
    if (state == Resolving || state == Rejecting) {
        // |ref| was called in |resolveOrReject|.
        deref();
    }
}

} // namespace blink