/**
 * Copyright (c) 2016 - 2020, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, 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.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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 "sdk_common.h"
#if NRF_MODULE_ENABLED(APP_USBD_HID_GENERIC)

#include <string.h>
#include "app_usbd_hid_generic.h"
#include "app_util_platform.h"


/**
 * @ingroup app_usbd_hid_generic
 *
 * Module with types, definitions and API used by HID generic.
 * @{
 */

/**
 * @brief Auxiliary function to access HID generic context data.
 *
 * @param[in] p_generic HID generic instance.
 *
 * @return HID generic class instance data context.
 */
static inline app_usbd_hid_generic_ctx_t *
hid_generic_ctx_get(app_usbd_hid_generic_t const * p_generic)
{
    ASSERT(p_generic != NULL);
    ASSERT(p_generic->specific.p_data != NULL);
    return &p_generic->specific.p_data->ctx;
}


/**
 * @brief Auxiliary function to access HID generic instance data.
 *
 * @param[in] p_inst Class instance data.
 *
 * @return HID generic class instance data.
 */
static inline app_usbd_hid_generic_t const *
hid_generic_get(app_usbd_class_inst_t const * p_inst)
{
    ASSERT(p_inst != NULL);
    return (app_usbd_hid_generic_t const *)p_inst;
}


/**
 * @brief Returns report ID buffer descriptor.
 *
 * @param[in] p_generic Internal HID generic context.
 *
 * @return HID report buffer.
 */
static inline app_usbd_hid_report_buffer_t *
hid_generic_rep_buffer_get(app_usbd_hid_generic_t const * p_generic)
{
    ASSERT(p_generic != NULL);
    app_usbd_hid_inst_t const * p_hinst = &p_generic->specific.inst.hid_inst;

    return app_usbd_hid_rep_buff_in_get(p_hinst);
}


/**
 * @brief Auxiliary function to prepare report transfer buffer to next transfer.
 *
 * @param[in] p_generic HID generic instance.
 *
 * @retval true  Next transfer required.
 * @retval false Next transfer not required.
 */
static inline bool hid_generic_transfer_next(app_usbd_hid_generic_t const * p_generic)
{
    nrf_queue_t const * p_rep_in_queue = p_generic->specific.inst.p_rep_in_queue;

    return !nrf_queue_is_empty(p_rep_in_queue);
}


/**
 * @brief Triggers IN endpoint transfer.
 *
 * @param[in] p_generic HID generic instance.
 *
 * @return Standard error code.
 */
static inline ret_code_t hid_generic_transfer_set(app_usbd_hid_generic_t const * p_generic)
{
    app_usbd_class_inst_t const * p_inst        = (app_usbd_class_inst_t const *)p_generic;
    app_usbd_hid_generic_ctx_t  * p_generic_ctx = hid_generic_ctx_get(p_generic);

    nrf_drv_usbd_ep_t ep_addr = app_usbd_hid_epin_addr_get(p_inst);

    app_usbd_hid_state_flag_clr(&p_generic_ctx->hid_ctx,
                                APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);

    if (!hid_generic_transfer_next(p_generic))
    {
        return NRF_SUCCESS;
    }

    app_usbd_hid_report_buffer_t * p_rep_buff     = hid_generic_rep_buffer_get(p_generic);
    nrf_queue_t const            * p_rep_in_queue = p_generic->specific.inst.p_rep_in_queue;

    ret_code_t ret = nrf_queue_pop(p_rep_in_queue, p_rep_buff);
    ASSERT(ret == NRF_SUCCESS);

    NRF_DRV_USBD_TRANSFER_IN(transfer, p_rep_buff->p_buff, p_rep_buff->size);
    CRITICAL_REGION_ENTER();
    ret = app_usbd_ep_transfer(ep_addr, &transfer);
    if (ret == NRF_SUCCESS)
    {
        app_usbd_hid_state_flag_set(&p_generic_ctx->hid_ctx,
                                    APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);
    }
    CRITICAL_REGION_EXIT();

    return ret;
}

ret_code_t hid_generic_clear_buffer(app_usbd_class_inst_t const * p_inst)
{
    ASSERT(p_inst != NULL);

    app_usbd_hid_generic_t const *        p_generic        = hid_generic_get(p_inst);
    app_usbd_hid_generic_ctx_t *          p_generic_ctx    = hid_generic_ctx_get(p_generic);
    app_usbd_hid_report_buffer_t       *  p_rep_buffer     = hid_generic_rep_buffer_get(p_generic);
    nrf_queue_t const                  *  p_rep_in_queue   = p_generic->specific.inst.p_rep_in_queue;
    ret_code_t ret = NRF_SUCCESS;

    /* Clear all queued reports */
    while(ret != NRF_ERROR_NOT_FOUND)
    {
        ret = nrf_queue_pop(p_rep_in_queue, p_rep_buffer);
    }

    CRITICAL_REGION_ENTER();
    uint8_t iface_count = app_usbd_class_iface_count_get(p_inst);

    app_usbd_class_iface_conf_t const * p_iface = NULL;
    for (uint8_t i = 0; i < iface_count; ++i)
    {
        p_iface = app_usbd_class_iface_get(p_inst, i);

        uint8_t ep_count = app_usbd_class_iface_ep_count_get(p_iface);

        for (uint8_t j = 0; j < ep_count; ++j)
        {
            /*Abort transfer on every IN endpoint*/
            app_usbd_class_ep_conf_t const * p_ep = app_usbd_class_iface_ep_get(p_iface, j);

            ASSERT(!NRF_USBD_EPISO_CHECK(p_ep->address));

            if (NRF_USBD_EPIN_CHECK(p_ep->address))
            {
                nrf_drv_usbd_ep_abort(p_ep->address);
            }

        }
    }

    app_usbd_hid_state_flag_clr(&p_generic_ctx->hid_ctx, APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);
    CRITICAL_REGION_EXIT();

    return ret;
}


ret_code_t app_usbd_hid_generic_in_report_set(app_usbd_hid_generic_t const * p_generic,
                                              const void                   * p_buff,
                                              size_t                         size)
{
    app_usbd_hid_generic_ctx_t       * p_generic_ctx  = hid_generic_ctx_get(p_generic);
    nrf_queue_t const                * p_rep_in_queue = p_generic->specific.inst.p_rep_in_queue;
    const app_usbd_hid_report_buffer_t rep_buff       = {
        .p_buff = (void *)p_buff,
        .size   = size,
    };

    if (nrf_queue_push(p_rep_in_queue, &rep_buff) != NRF_SUCCESS)
    {
        return NRF_ERROR_BUSY;
    }

    ret_code_t ret = NRF_SUCCESS;
    if (app_usbd_hid_trans_required(&p_generic_ctx->hid_ctx) && 
        !p_generic_ctx->hid_ctx.idle_on)
    {
        ret = hid_generic_transfer_set(p_generic);
    }

    return ret;
}

ret_code_t app_usbd_hid_generic_idle_report_set(app_usbd_hid_generic_t const * p_generic,
                                                const void                   * p_buff,
                                                size_t                         size)
{
    app_usbd_class_inst_t const  * p_inst        = (app_usbd_class_inst_t const *)p_generic;
    app_usbd_hid_generic_ctx_t   * p_generic_ctx = hid_generic_ctx_get(p_generic);
    ret_code_t ret;
    nrf_drv_usbd_ep_t ep_addr = app_usbd_hid_epin_addr_get(p_inst);

    app_usbd_hid_state_flag_clr(&p_generic_ctx->hid_ctx,
                                APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);

    NRF_DRV_USBD_TRANSFER_IN(transfer, p_buff, size);

    CRITICAL_REGION_ENTER();
    ret = app_usbd_ep_transfer(ep_addr, &transfer);
    if (ret == NRF_SUCCESS)
    {
        app_usbd_hid_state_flag_set(&p_generic_ctx->hid_ctx,
                                    APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);
    }
    CRITICAL_REGION_EXIT();

    return ret;
}


const void * app_usbd_hid_generic_in_report_get(app_usbd_hid_generic_t const * p_generic,
                                                size_t                       * p_size)
{
    app_usbd_hid_inst_t const * p_hinst = &p_generic->specific.inst.hid_inst;

    *p_size = p_hinst->p_rep_buffer_in->size;
    return p_hinst->p_rep_buffer_in->p_buff;
}


const void * app_usbd_hid_generic_out_report_get(app_usbd_hid_generic_t const * p_generic,
                                                 size_t                       * p_size)
{
    app_usbd_hid_inst_t const * p_hinst = &p_generic->specific.inst.hid_inst;

    *p_size = p_hinst->p_rep_buffer_out->size;
    return p_hinst->p_rep_buffer_out->p_buff;
}

const void * app_usbd_hid_generic_feature_report_get(app_usbd_hid_generic_t const * p_generic,
                                                     size_t                       * p_size)
{
    app_usbd_hid_inst_t const * p_hinst = &p_generic->specific.inst.hid_inst;

    *p_size = p_hinst->p_rep_buffer_feature->size;
    return p_hinst->p_rep_buffer_feature->p_buff;
}

/**
 * @brief @ref app_usbd_hid_interface_t::on_get_report
 */
static ret_code_t hid_generic_on_get_report(app_usbd_class_inst_t const * p_inst,
                                            app_usbd_setup_evt_t const  * p_setup_ev)
{
    app_usbd_hid_generic_t const * p_hinst = hid_generic_get(p_inst);
    uint8_t const * p_rep_buffer = NULL;
    size_t buffer_size = 0;

    if (p_setup_ev->setup.wValue.hb == APP_USBD_HID_REPORT_TYPE_INPUT)
    {
        p_rep_buffer = app_usbd_hid_generic_in_report_get(p_hinst, &buffer_size);
    }
    else if (p_setup_ev->setup.wValue.hb == APP_USBD_HID_REPORT_TYPE_OUTPUT)
    {
        p_rep_buffer = app_usbd_hid_generic_out_report_get(p_hinst, &buffer_size);
    }
    else if (p_setup_ev->setup.wValue.hb == APP_USBD_HID_REPORT_TYPE_FEATURE)
    {
        p_rep_buffer = app_usbd_hid_generic_feature_report_get(p_hinst, &buffer_size);
    }
    else
    {
        return NRF_ERROR_NOT_SUPPORTED;
    }

    return app_usbd_core_setup_rsp(&(p_setup_ev->setup), p_rep_buffer, buffer_size);
}


static ret_code_t hid_generic_on_set_report_data_cb(nrf_drv_usbd_ep_status_t status,
                                                    void                   * p_context)
{
    app_usbd_hid_user_ev_handler_t handler;
    app_usbd_hid_generic_t const * p_generic = (app_usbd_hid_generic_t const *)p_context;

    if (status != NRF_USBD_EP_OK)
    {
        return NRF_ERROR_INTERNAL;
    }

    handler = p_generic->specific.inst.hid_inst.user_event_handler;
    handler((app_usbd_class_inst_t const *)p_generic,
            APP_USBD_HID_USER_EVT_OUT_REPORT_READY);
    return NRF_SUCCESS;
}

static ret_code_t hid_generic_on_set_report_feature_data_cb(nrf_drv_usbd_ep_status_t status,
                                                            void                   * p_context)
{
    app_usbd_hid_user_ev_handler_t handler;
    app_usbd_hid_generic_t const * p_generic = (app_usbd_hid_generic_t const *)p_context;

    if (status != NRF_USBD_EP_OK)
    {
        return NRF_ERROR_INTERNAL;
    }

    handler = p_generic->specific.inst.hid_inst.user_event_handler;
    handler((app_usbd_class_inst_t const *)p_generic,
            APP_USBD_HID_USER_EVT_FEATURE_REPORT_READY);
    return NRF_SUCCESS;
}

/**
 * @brief @ref app_usbd_hid_interface_t::on_set_report
 */
static ret_code_t hid_generic_on_set_report(app_usbd_class_inst_t const * p_inst,
                                            app_usbd_setup_evt_t const  * p_setup_ev)
{
    if (p_setup_ev->setup.wValue.hb == APP_USBD_HID_REPORT_TYPE_OUTPUT)
    {
        app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);

        /*Request setup data*/
        app_usbd_hid_report_buffer_t const * p_rep_buff;

        p_rep_buff = app_usbd_hid_rep_buff_out_get(&p_generic->specific.inst.hid_inst);

        p_rep_buff->p_buff[0] = p_setup_ev->setup.wValue.lb;
        NRF_DRV_USBD_TRANSFER_OUT(transfer, p_rep_buff->p_buff + 1, p_rep_buff->size - 1);

        ret_code_t ret;
        CRITICAL_REGION_ENTER();
        ret = app_usbd_ep_transfer(NRF_DRV_USBD_EPOUT0, &transfer);
        if (ret == NRF_SUCCESS)
        {
            app_usbd_core_setup_data_handler_desc_t desc = {
                .handler   = hid_generic_on_set_report_data_cb,
                .p_context = (void *)p_generic
            };

            ret = app_usbd_core_setup_data_handler_set(NRF_DRV_USBD_EPOUT0, &desc);
        }
        CRITICAL_REGION_EXIT();
        return ret;

     }
    else if (p_setup_ev->setup.wValue.hb == APP_USBD_HID_REPORT_TYPE_FEATURE)
    {
         app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);

        /*Request setup data*/
        app_usbd_hid_report_buffer_t const * p_rep_buff;

        p_rep_buff = app_usbd_hid_rep_buff_feature_get(&p_generic->specific.inst.hid_inst);

        NRF_DRV_USBD_TRANSFER_OUT(transfer, p_rep_buff->p_buff, p_rep_buff->size);

        ret_code_t ret;
        CRITICAL_REGION_ENTER();
        ret = app_usbd_ep_transfer(NRF_DRV_USBD_EPOUT0, &transfer);
        if (ret == NRF_SUCCESS)
        {
            app_usbd_core_setup_data_handler_desc_t desc = {
                .handler   = hid_generic_on_set_report_feature_data_cb,
                .p_context = (void *)p_generic
            };

            ret = app_usbd_core_setup_data_handler_set(NRF_DRV_USBD_EPOUT0, &desc);
        }
        CRITICAL_REGION_EXIT();
        return ret;
    }
    return NRF_ERROR_NOT_SUPPORTED;
}


/**
 * @brief @ref app_usbd_hid_interface_t::ep_transfer_in
 */
static ret_code_t hid_generic_ep_transfer_in(app_usbd_class_inst_t const * p_inst)
{
    app_usbd_hid_generic_t const * p_generic     = hid_generic_get(p_inst);
    app_usbd_hid_generic_ctx_t   * p_generic_ctx = hid_generic_ctx_get(p_generic);

    nrf_queue_t const * p_rep_in_queue = p_generic->specific.inst.p_rep_in_queue;

    if (nrf_queue_is_empty(p_rep_in_queue))
    {
        app_usbd_hid_state_flag_clr(&p_generic_ctx->hid_ctx,
                                    APP_USBD_HID_STATE_FLAG_TRANS_IN_PROGRESS);
        return NRF_SUCCESS;
    }

    /* Get next report to send */
    return hid_generic_transfer_set((app_usbd_hid_generic_t const *)p_inst);
}


/**
 * @brief @ref app_usbd_hid_interface_t::ep_transfer_out
 */
static ret_code_t hid_generic_ep_transfer_out(app_usbd_class_inst_t const * p_inst)
{

    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    nrf_drv_usbd_ep_t              ep_addr   = app_usbd_hid_epout_addr_get(p_inst);

    /*Request setup data*/
    app_usbd_hid_report_buffer_t const * p_rep_buff;

    p_rep_buff = app_usbd_hid_rep_buff_out_get(&p_generic->specific.inst.hid_inst);
    NRF_DRV_USBD_TRANSFER_OUT(transfer, p_rep_buff->p_buff, p_rep_buff->size);

    return app_usbd_ep_transfer(ep_addr, &transfer);
}


/**
 * @brief @ref app_usbd_class_interface_t::event_handler
 */
static ret_code_t hid_generic_event_handler(app_usbd_class_inst_t const  * p_inst,
                                            app_usbd_complex_evt_t const * p_event)
{
    ASSERT(p_inst != NULL);
    ASSERT(p_event != NULL);

    app_usbd_hid_generic_t const * p_generic     = hid_generic_get(p_inst);
    app_usbd_hid_inst_t const    * p_hinst       = &p_generic->specific.inst.hid_inst;
    app_usbd_hid_generic_ctx_t   * p_generic_ctx = hid_generic_ctx_get(p_generic);
    app_usbd_hid_ctx_t           * p_hid_ctx     = &p_generic_ctx->hid_ctx;

    /*Try handle event by generic HID event handler*/
    return app_usbd_hid_event_handler(p_inst, p_hinst, p_hid_ctx, p_event);
}


static uint8_t hid_generic_get_class_descriptors_count(app_usbd_class_inst_t const * p_inst)
{
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_inst_t const    * p_hinst   = &p_generic->specific.inst.hid_inst;

    return p_hinst->subclass_desc_count;
}


static app_usbd_descriptor_t hid_generic_get_class_descriptors_type(
    app_usbd_class_inst_t const * p_inst,
    uint8_t                       desc_num)
{
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_inst_t const    * p_hinst   = &p_generic->specific.inst.hid_inst;

    return p_hinst->p_subclass_desc[desc_num]->type;
}

static size_t hid_generic_get_class_descriptors_length(app_usbd_class_inst_t const * p_inst,
                                                       uint8_t                       desc_num)
{
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_inst_t const    * p_hinst   = &p_generic->specific.inst.hid_inst;

    return p_hinst->p_subclass_desc[desc_num]->size;
}


static const uint8_t * hid_generic_get_class_descriptors_data(app_usbd_class_inst_t const * p_inst,
                                                              uint8_t                       desc_num,
                                                              uint32_t                      cur_byte)
{
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_inst_t const    * p_hinst   = &p_generic->specific.inst.hid_inst;
    const uint8_t * p_byte = &p_hinst->p_subclass_desc[desc_num]->p_data[cur_byte];

    return p_byte;
}


/**
 * @brief @ref app_usbd_class_interface_t::feed_descriptors
 */
static bool hid_generic_feed_descriptors(app_usbd_class_descriptor_ctx_t  * p_ctx,
                                         app_usbd_class_inst_t const      * p_inst,
                                         uint8_t                          * p_buff,
                                         size_t                             max_size)
{
    static uint8_t ifaces   = 0;
    ifaces = app_usbd_class_iface_count_get(p_inst);
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);

    APP_USBD_CLASS_DESCRIPTOR_BEGIN(p_ctx, p_buff, max_size);

    static uint8_t i = 0;

    for (i = 0; i < ifaces; i++)
    {
        /* INTERFACE DESCRIPTOR */
        APP_USBD_CLASS_DESCRIPTOR_WRITE(0x09); // bLength
        APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_DESCRIPTOR_INTERFACE); // bDescriptorType = Interface

        static app_usbd_class_iface_conf_t const * p_cur_iface = NULL;
        p_cur_iface = app_usbd_class_iface_get(p_inst, i);
        APP_USBD_CLASS_DESCRIPTOR_WRITE(app_usbd_class_iface_number_get(p_cur_iface)); // bInterfaceNumber

        APP_USBD_CLASS_DESCRIPTOR_WRITE(0x00); // bAlternateSetting
        APP_USBD_CLASS_DESCRIPTOR_WRITE(app_usbd_class_iface_ep_count_get(p_cur_iface)); // bNumEndpoints
        APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_HID_CLASS); // bInterfaceClass = HID
        APP_USBD_CLASS_DESCRIPTOR_WRITE(p_generic->specific.inst.hid_inst.subclass_boot); // bInterfaceSubclass (Boot Interface)
        APP_USBD_CLASS_DESCRIPTOR_WRITE(p_generic->specific.inst.hid_inst.protocol); // bInterfaceProtocol
        APP_USBD_CLASS_DESCRIPTOR_WRITE(0x00); // iInterface

        /* HID DESCRIPTOR */
        APP_USBD_CLASS_DESCRIPTOR_WRITE(0x09); // bLength
        APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_HID_DESCRIPTOR_HID);  // bDescriptorType = HID
        APP_USBD_CLASS_DESCRIPTOR_WRITE(LSB_16(APP_USBD_HID_BCD_VER)); // bcdHID LSB
        APP_USBD_CLASS_DESCRIPTOR_WRITE(MSB_16(APP_USBD_HID_BCD_VER)); // bcdHID MSB
        APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_HID_COUNTRY_NOT_SUPPORTED); // bCountryCode
        APP_USBD_CLASS_DESCRIPTOR_WRITE(hid_generic_get_class_descriptors_count(p_inst)); // bNumDescriptors

        static uint8_t class_desc_cnt = 0;
        class_desc_cnt = hid_generic_get_class_descriptors_count(p_inst);
        static uint8_t  j              = 0;
        static uint16_t class_desc_len = 0;

        for (j = 0; j < class_desc_cnt; j++)
        {
            APP_USBD_CLASS_DESCRIPTOR_WRITE(hid_generic_get_class_descriptors_type(p_inst, j)); // bDescriptorType

            class_desc_len = hid_generic_get_class_descriptors_length(p_inst, j);
            APP_USBD_CLASS_DESCRIPTOR_WRITE(LSB_16(class_desc_len)); // wDescriptorLength LSB
            APP_USBD_CLASS_DESCRIPTOR_WRITE(MSB_16(class_desc_len)); // wDescriptorLength MSB
        }

        static uint8_t endpoints = 0;
        endpoints = app_usbd_class_iface_ep_count_get(p_cur_iface);

        for (j = 0; j < endpoints; j++)
        {
            /* ENDPOINT DESCRIPTOR */
            APP_USBD_CLASS_DESCRIPTOR_WRITE(0x07); // bLength
            APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_DESCRIPTOR_ENDPOINT); // bDescriptorType = Endpoint

            static app_usbd_class_ep_conf_t const * p_cur_ep = NULL;
            p_cur_ep = app_usbd_class_iface_ep_get(p_cur_iface, j);
            APP_USBD_CLASS_DESCRIPTOR_WRITE(app_usbd_class_ep_address_get(p_cur_ep)); // bEndpointAddress
            APP_USBD_CLASS_DESCRIPTOR_WRITE(APP_USBD_DESCRIPTOR_EP_ATTR_TYPE_INTERRUPT); // bmAttributes
            APP_USBD_CLASS_DESCRIPTOR_WRITE(LSB_16(NRF_DRV_USBD_EPSIZE)); // wMaxPacketSize LSB
            APP_USBD_CLASS_DESCRIPTOR_WRITE(MSB_16(NRF_DRV_USBD_EPSIZE)); // wMaxPacketSize MSB
            APP_USBD_CLASS_DESCRIPTOR_WRITE(p_generic->specific.inst.hid_inst.p_ep_interval[j]); // bInterval
        }
    }

    APP_USBD_CLASS_DESCRIPTOR_END();
}

ret_code_t hid_generic_on_set_protocol(app_usbd_hid_generic_t const * p_generic, app_usbd_hid_user_event_t ev)
{
    app_usbd_hid_generic_ctx_t * p_generic_ctx = hid_generic_ctx_get(p_generic);
    if (ev == APP_USBD_HID_USER_EVT_SET_BOOT_PROTO)
    {
        p_generic_ctx->hid_ctx.selected_protocol = APP_USBD_HID_PROTO_BOOT;
    }
    else if (ev == APP_USBD_HID_USER_EVT_SET_REPORT_PROTO)
    {
        p_generic_ctx->hid_ctx.selected_protocol = APP_USBD_HID_PROTO_REPORT;
    }
    else
    {
        return NRF_ERROR_NOT_SUPPORTED;
    }
    return NRF_SUCCESS;
}

ret_code_t hid_generic_idle_handler_set(app_usbd_class_inst_t const * p_inst,
                                        app_usbd_hid_idle_handler_t handler)
{
    ASSERT(handler != NULL);
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_generic_ctx_t   * p_generic_ctx = hid_generic_ctx_get(p_generic);

    p_generic_ctx->hid_ctx.idle_handler = handler;
    return NRF_SUCCESS;
}

static ret_code_t hid_generic_on_idle(app_usbd_class_inst_t const * p_inst, uint8_t report_id)
{
    app_usbd_hid_generic_t const * p_generic = hid_generic_get(p_inst);
    app_usbd_hid_generic_ctx_t   * p_generic_ctx = hid_generic_ctx_get(p_generic);
    
    if(p_generic_ctx->hid_ctx.idle_handler != NULL)
    {
        return p_generic_ctx->hid_ctx.idle_handler(p_inst, report_id);
    }
    else
    {
        return NRF_ERROR_NOT_SUPPORTED;
    }
}

/** @} */

const app_usbd_hid_methods_t app_usbd_hid_generic_methods = {
    .on_get_report              = hid_generic_on_get_report,
    .on_set_report              = hid_generic_on_set_report,
    .ep_transfer_in             = hid_generic_ep_transfer_in,
    .ep_transfer_out            = hid_generic_ep_transfer_out,
    .subclass_length            = hid_generic_get_class_descriptors_length,
    .subclass_data              = hid_generic_get_class_descriptors_data,
    .on_idle                    = hid_generic_on_idle,
    .set_idle_handler           = hid_generic_idle_handler_set,
};

const app_usbd_class_methods_t app_usbd_generic_class_methods = {
    .event_handler            = hid_generic_event_handler,
    .feed_descriptors         = hid_generic_feed_descriptors,
};

#endif //NRF_MODULE_ENABLED(APP_USBD_HID_GENERIC)
