// Copyright 2021 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "src/dawn_node/binding/AsyncRunner.h"

#include <cassert>
#include <limits>

namespace wgpu::binding {

    AsyncRunner::AsyncRunner(Napi::Env env, wgpu::Device device) : env_(env), device_(device) {
    }

    void AsyncRunner::Begin() {
        assert(count_ != std::numeric_limits<decltype(count_)>::max());
        if (count_++ == 0) {
            QueueTick();
        }
    }

    void AsyncRunner::End() {
        assert(count_ > 0);
        count_--;
    }

    void AsyncRunner::QueueTick() {
        // TODO(crbug.com/dawn/1127): We probably want to reduce the frequency at which this gets
        // called.
        if (tick_queued_) {
            return;
        }
        tick_queued_ = true;
        env_.Global()
            .Get("setImmediate")
            .As<Napi::Function>()
            .Call({
                // TODO(crbug.com/dawn/1127): Create once, reuse.
                Napi::Function::New(env_,
                                    [this](const Napi::CallbackInfo&) {
                                        tick_queued_ = false;
                                        if (count_ > 0) {
                                            device_.Tick();
                                            QueueTick();
                                        }
                                    }),
            });
    }

}  // namespace wgpu::binding