/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * 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.
 */

#ifndef OHOS_ROSEN_WINDOW_SCENE_TASK_SCHEDULER_H
#define OHOS_ROSEN_WINDOW_SCENE_TASK_SCHEDULER_H

#include <event_handler.h>

#include <unistd.h>

namespace OHOS::Rosen {

void StartTraceForSyncTask(std::string name);
void FinishTraceForSyncTask();

class TaskScheduler : public std::enable_shared_from_this<TaskScheduler> {
public:
    explicit TaskScheduler(const std::string& threadName);
    ~TaskScheduler() = default;

    std::shared_ptr<AppExecFwk::EventHandler> GetEventHandler();
    using Task = std::function<void()>;
    void PostAsyncTask(Task&& task, const std::string& name = "ssmTask", int64_t delayTime = 0);
    void PostVoidSyncTask(Task&& task, const std::string& name = "ssmTask");
    void PostTask(Task&& task, const std::string& name, int64_t delayTime = 0);
    void RemoveTask(const std::string& name);
    template<typename SyncTask, typename Return = std::invoke_result_t<SyncTask>>
    Return PostSyncTask(SyncTask&& task, const std::string& name = "ssmTask")
    {
        Return ret;
        if (handler_->GetEventRunner()->IsCurrentRunnerThread()) {
            StartTraceForSyncTask(name);
            ret = task();
            FinishTraceForSyncTask();
            return ret;
        }
        auto syncTask = [weak = weak_from_this(), &ret, &task, name]() {
            StartTraceForSyncTask(name);
            ret = task();
            FinishTraceForSyncTask();
            if (auto self = weak.lock()) {
                self->ExecuteExportTask();
            }
        };
        AppExecFwk::EventQueue::Priority priority = AppExecFwk::EventQueue::Priority::IMMEDIATE;
        static pid_t pid = getpid();
        if (pid == gettid()) {
            priority = AppExecFwk::EventQueue::Priority::VIP;
        }
        handler_->PostSyncTask(std::move(syncTask), "wms:" + name, priority);
        return ret;
    }

    void SetExportHandler(const std::shared_ptr<AppExecFwk::EventHandler>& handler);
    /*
     * add export task, will be executed after a task OS_SceneSession,
     * same name means same task, will be only executed once
     */
    void AddExportTask(std::string taskName, Task task);

private:
    void ExecuteExportTask();
    std::unordered_map<std::string, Task> exportFuncMap_; // will used in OS_SceneSession
    std::shared_ptr<AppExecFwk::EventHandler> handler_;
    std::weak_ptr<AppExecFwk::EventHandler> exportHandler_;
    pid_t ssmTid_ = 0;
};
} // namespace OHOS::Rosen
#endif // OHOS_ROSEN_WINDOW_SCENE_TASK_SCHEDULER_H