/*
 *
 *    Copyright (c) 2020 Project CHIP Authors
 *    Copyright (c) 2018 Nest Labs, Inc.
 *
 *    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.
 */

/**
 *    @file
 *          Provides an generic implementation of PlatformManager features
 *          for use on FreeRTOS platforms.
 */

#pragma once

#include <platform/CHIPDeviceConfig.h>
#include <platform/internal/GenericPlatformManagerImpl.h>

#if defined(ESP_PLATFORM)
#include "freertos/FreeRTOS.h"
#include "freertos/queue.h"
#include "freertos/semphr.h"
#include "freertos/task.h"
#else
#include "FreeRTOS.h"
#include "queue.h"
#include "semphr.h"
#include "task.h"
#endif

#include <atomic>

namespace chip {
namespace DeviceLayer {
namespace Internal {

/**
 * Provides a generic implementation of PlatformManager features that works on FreeRTOS platforms.
 *
 * This template contains implementations of select features from the PlatformManager abstract
 * interface that are suitable for use on FreeRTOS-based platforms.  It is intended to be inherited
 * (directly or indirectly) by the PlatformManagerImpl class, which also appears as the template's
 * ImplClass parameter.
 */
template <class ImplClass>
class GenericPlatformManagerImpl_FreeRTOS : public GenericPlatformManagerImpl<ImplClass>
{

protected:
    TimeOut_t mNextTimerBaseTime;
    TickType_t mNextTimerDurationTicks;
    SemaphoreHandle_t mChipStackLock = NULL;
    QueueHandle_t mChipEventQueue    = NULL;
    TaskHandle_t mEventLoopTask      = NULL;
    bool mChipTimerActive;

#if defined(CHIP_DEVICE_CONFIG_ENABLE_BG_EVENT_PROCESSING) && CHIP_DEVICE_CONFIG_ENABLE_BG_EVENT_PROCESSING
    QueueHandle_t mBackgroundEventQueue   = NULL;
    TaskHandle_t mBackgroundEventLoopTask = NULL;
#endif

    // ===== Methods that implement the PlatformManager abstract interface.

    CHIP_ERROR _InitChipStack();

    void _LockChipStack(void);
    bool _TryLockChipStack(void);
    void _UnlockChipStack(void);

    CHIP_ERROR _PostEvent(const ChipDeviceEvent * event);
    void _RunEventLoop(void);
    CHIP_ERROR _StartEventLoopTask(void);
    CHIP_ERROR _StopEventLoopTask();
    CHIP_ERROR _StartChipTimer(System::Clock::Timeout duration);
    void _Shutdown(void);

#if CHIP_STACK_LOCK_TRACKING_ENABLED
    bool _IsChipStackLockedByCurrentThread() const;
#endif

    CHIP_ERROR _PostBackgroundEvent(const ChipDeviceEvent * event);
    void _RunBackgroundEventLoop(void);
    CHIP_ERROR _StartBackgroundEventLoopTask(void);
    CHIP_ERROR _StopBackgroundEventLoopTask();

    // ===== Methods available to the implementation subclass.

    void PostEventFromISR(const ChipDeviceEvent * event, BaseType_t & yieldRequired);

private:
    // ===== Private members for use by this class only.

    inline ImplClass * Impl() { return static_cast<ImplClass *>(this); }

    static void EventLoopTaskMain(void * arg);

#if defined(CHIP_CONFIG_FREERTOS_USE_STATIC_QUEUE) && CHIP_CONFIG_FREERTOS_USE_STATIC_QUEUE
    uint8_t mEventQueueBuffer[CHIP_DEVICE_CONFIG_MAX_EVENT_QUEUE_SIZE * sizeof(ChipDeviceEvent)];
    StaticQueue_t mEventQueueStruct;
#endif
#if defined(CHIP_CONFIG_FREERTOS_USE_STATIC_TASK) && CHIP_CONFIG_FREERTOS_USE_STATIC_TASK
    StackType_t mEventLoopStack[CHIP_DEVICE_CONFIG_CHIP_TASK_STACK_SIZE / sizeof(StackType_t)];
    StaticTask_t mEventLoopTaskStruct;
#endif

    std::atomic<bool> mShouldRunEventLoop;

#if defined(CHIP_DEVICE_CONFIG_ENABLE_BG_EVENT_PROCESSING) && CHIP_DEVICE_CONFIG_ENABLE_BG_EVENT_PROCESSING
    static void BackgroundEventLoopTaskMain(void * arg);

#if defined(CHIP_CONFIG_FREERTOS_USE_STATIC_QUEUE) && CHIP_CONFIG_FREERTOS_USE_STATIC_QUEUE
    uint8_t mBackgroundQueueBuffer[CHIP_DEVICE_CONFIG_BG_MAX_EVENT_QUEUE_SIZE * sizeof(ChipDeviceEvent)];
    StaticQueue_t mBackgroundQueueStruct;
#endif
#if defined(CHIP_CONFIG_FREERTOS_USE_STATIC_TASK) && CHIP_CONFIG_FREERTOS_USE_STATIC_TASK
    StackType_t mBackgroundEventLoopStack[CHIP_DEVICE_CONFIG_BG_TASK_STACK_SIZE / sizeof(StackType_t)];
    StaticTask_t mBackgroundEventLoopTaskStruct;
#endif

    std::atomic<bool> mShouldRunBackgroundEventLoop;
#endif

#if defined(CHIP_CONFIG_FREERTOS_USE_STATIC_SEMAPHORE) && CHIP_CONFIG_FREERTOS_USE_STATIC_SEMAPHORE
    StaticSemaphore_t mChipStackLockMutex;
#endif
};

// Instruct the compiler to instantiate the template only when explicitly told to do so.
extern template class GenericPlatformManagerImpl_FreeRTOS<PlatformManagerImpl>;

} // namespace Internal
} // namespace DeviceLayer
} // namespace chip