/**
 * Copyright (c) 2016 - 2017, 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 <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include "nrf.h"
#include "nrf_drv_usbd.h"
#include "nrf_drv_clock.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "nrf_drv_power.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "app_timer.h"
#include "bsp.h"

/**
 * @brief APP_TIMER prescaler configuration
 */
#define APP_TIMER_PRESCALER     0
/**
 * @brief APP_TIMER size of operation queue
 */
#define APP_TIMER_OP_QUEUE_SIZE 2

/**
 * @brief Button used to simulate mouse move
 *
 * Every button press would move the cursor one step in the square.
 */
#define BTN_MOUSE_MOVE BSP_BOARD_BUTTON_0
/**
 * @brief Button for system OFF request
 *
 * This button would set the request for system OFF.
 */
#define BTN_SYSTEM_OFF BSP_BOARD_BUTTON_1

/**
 * @brief Configuration status LED
 *
 * This LED would blink quickly (5&nbsp;Hz) when device is not configured
 * or slowly (1&nbsp;Hz) when configured and working properly.
 */
#define LED_USB_STATUS BSP_BOARD_LED_0
/**
 * @brief Power detect LED
 *
 * The LED is ON when connection is detected on USB port.
 * It is turned off when connection is removed.
 */
#define LED_USB_POWER BSP_BOARD_LED_1

/**
 * @brief Running LED
 *
 * LED that turns on when program is not sleeping
 */
#define LED_RUNNING BSP_BOARD_LED_2

/**
 * @brief Active LED
 *
 * LED that turns on when program is not in system OFF
 */
#define LED_ACTIVE BSP_BOARD_LED_3

/**
 * @brief Enable power USB detection
 *
 * Configure if example supports USB port connection
 */
#ifndef USBD_POWER_DETECTION
#define USBD_POWER_DETECTION true
#endif

/**
 * @brief Startup delay
 *
 * Number of microseconds to start USBD after powering up.
 * Kind of port insert debouncing.
 */
#define STARTUP_DELAY 100


/** Maximum size of the packed transfered by EP0 */
#define EP0_MAXPACKETSIZE NRF_DRV_USBD_EPSIZE

/** Device descriptor */
#define USBD_DEVICE_DESCRIPTOR \
    0x12,                        /* bLength | size of descriptor                                                  */\
    0x01,                        /* bDescriptorType | descriptor type                                             */\
    0x00, 0x02,                  /* bcdUSB | USB spec release (ver 2.0)                                           */\
    0x00,                        /* bDeviceClass ¦ class code (each interface specifies class information)        */\
    0x00,                        /* bDeviceSubClass ¦ device sub-class (must be set to 0 because class code is 0) */\
    0x00,                        /* bDeviceProtocol | device protocol (no class specific protocol)                */\
    EP0_MAXPACKETSIZE,           /* bMaxPacketSize0 | maximum packet size (64 bytes)                              */\
    0x15, 0x19,                  /* vendor ID  (0x1915 Nordic)                                                    */\
    0x0A, 0x52,                  /* product ID (0x520A nRF52 HID mouse on nrf_drv)                                */\
    0x01, 0x01,                  /* bcdDevice | final device release number in BCD Format                         */\
    USBD_STRING_MANUFACTURER_IX, /* iManufacturer | index of manufacturer string                                  */\
    USBD_STRING_PRODUCT_IX,      /* iProduct | index of product string                                            */\
    USBD_STRING_SERIAL_IX,       /* iSerialNumber | Serial Number string                                          */\
    0x01                         /* bNumConfigurations | number of configurations                                 */

/** Configuration descriptor */
#define DEVICE_SELF_POWERED 1
#define REMOTE_WK 0
#define USBD_CONFIG_DESCRIPTOR_SIZE   9
#define USBD_CONFIG_DESCRIPTOR_FULL_SIZE   (9+(9+9+7))
#define USBD_CONFIG_DESCRIPTOR  \
    0x09,         /* bLength | length of descriptor                                             */\
    0x02,         /* bDescriptorType | descriptor type (CONFIGURATION)                          */\
    USBD_CONFIG_DESCRIPTOR_FULL_SIZE, 0x00,    /* wTotalLength | total length of descriptor(s)  */\
    0x01,         /* bNumInterfaces                                                             */\
    0x01,         /* bConfigurationValue                                                        */\
    0x00,         /* index of string Configuration | configuration string index (not supported) */\
    0x80|(DEVICE_SELF_POWERED<<6)|(REMOTE_WK<<5), /* bmAttributes                               */\
    49            /* maximum power in steps of 2mA (98mA)                                       */

#define USBD_INTERFACE0_DESCRIPTOR  \
    0x09,         /* bLength                                                                          */\
    0x04,         /* bDescriptorType | descriptor type (INTERFACE)                                    */\
    0x00,         /* bInterfaceNumber                                                                 */\
    0x00,         /* bAlternateSetting                                                                */\
    0x01,         /* bNumEndpoints | number of endpoints (1)                                          */\
    0x03,         /* bInterfaceClass | interface class (3..defined by USB spec: HID)                  */\
    0x01,         /* bInterfaceSubClass |interface sub-class (1..defined by USB spec: boot interface) */\
    0x02,         /* bInterfaceProtocol | interface protocol (1..defined by USB spec: mouse)          */\
    0x00          /* interface string index (not supported)                                           */

/**
 * HID Table must normally be between Interface and EndPoint Descriptor
 * as written in HID spec§7.1 but it doesn't work with OSR2.1
 */
#define USBD_HID0_DESCRIPTOR  \
    0x09,         /* bLength | length of descriptor (9 bytes)                    */\
    0x21,         /* bHIDDescriptor | descriptor type (HID)                      */\
    0x11, 0x01,   /* HID wBcdHID | Spec version 01.11                            */\
    0x00,         /* bCountryCode | HW Target country                            */\
    0x01,         /* bNumDescriptors | Number of HID class descriptors to follow */\
    0x22,         /* bDescriptorType | Report descriptor type is 0x22 (report)   */\
    (uint8_t)(USBD_MOUSE_REPORT_DESCRIPTOR_SIZE),      /* Total length of Report descr., low byte */ \
    (uint8_t)(USBD_MOUSE_REPORT_DESCRIPTOR_SIZE / 256) /* Total length of Report descr., high byte */

#define USBD_ENDPOINT1_DESCRIPTOR  \
    0x07,         /* bLength | length of descriptor (7 bytes)                                     */\
    0x05,         /* bDescriptorType | descriptor type (ENDPOINT)                                 */\
    0x81,         /* bEndpointAddress | endpoint address (IN endpoint, endpoint 1)                */\
    0x03,         /* bmAttributes | endpoint attributes (interrupt)                               */\
    0x08,0x00,    /* bMaxPacketSizeLowByte,bMaxPacketSizeHighByte | maximum packet size (8 bytes) */\
    0x08          /* bInterval | polling interval (10ms)                                          */


/**
 * String config descriptor
 */
#define USBD_STRING_LANG_IX  0x00
#define USBD_STRING_LANG \
    0x04,         /* length of descriptor                   */\
    0x03,         /* descriptor type                        */\
    0x09,         /*                                        */\
    0x04          /* Supported LangID = 0x0409 (US-English) */

#define USBD_STRING_MANUFACTURER_IX  0x01
#define USBD_STRING_MANUFACTURER \
    42,           /* length of descriptor (? bytes)   */\
    0x03,         /* descriptor type                  */\
    'N', 0x00,    /* Define Unicode String "Logitech  */\
    'o', 0x00, \
    'r', 0x00, \
    'd', 0x00, \
    'i', 0x00, \
    'c', 0x00, \
    ' ', 0x00, \
    'S', 0x00, \
    'e', 0x00, \
    'm', 0x00, \
    'i', 0x00, \
    'c', 0x00, \
    'o', 0x00, \
    'n', 0x00, \
    'd', 0x00, \
    'u', 0x00, \
    'c', 0x00, \
    't', 0x00, \
    'o', 0x00, \
    'r', 0x00

#define USBD_STRING_PRODUCT_IX  0x02
#define USBD_STRING_PRODUCT \
    72,           /* length of descriptor (? bytes)         */\
    0x03,         /* descriptor type                        */\
    'n', 0x00,    /* generic unicode string for all devices */\
    'R', 0x00, \
    'F', 0x00, \
    '5', 0x00, \
    '2', 0x00, \
    ' ', 0x00, \
    'U', 0x00, \
    'S', 0x00, \
    'B', 0x00, \
    ' ', 0x00, \
    'H', 0x00, \
    'I', 0x00, \
    'D', 0x00, \
    ' ', 0x00, \
    'm', 0x00, \
    'o', 0x00, \
    'u', 0x00, \
    's', 0x00, \
    'e', 0x00, \
    ' ', 0x00, \
    'o', 0x00, \
    'n', 0x00, \
    ' ', 0x00, \
    'n', 0x00, \
    'r', 0x00, \
    'f', 0x00, \
    '_', 0x00, \
    'd', 0x00, \
    'r', 0x00, \
    'v', 0x00, \
    ' ', 0x00, \
    'D', 0x00, \
    'e', 0x00, \
    'm', 0x00, \
    'o', 0x00, \

#define USBD_STRING_SERIAL_IX  0x00

#define USBD_MOUSE_REPORT_DESCRIPTOR_SIZE  46
#define USBD_MOUSE_REPORT_DESCRIPTOR \
    0x05, 0x01,     /* usage page (generic desktop). Global item, applies to all subsequent items   */\
    0x09, 0x02,     /* usage (mouse). Local item                                                    */\
    0xA1, 0x01,     /* collection (application)                                                     */\
    0x09, 0x01,     /* usage (pointer)                                                              */\
    0xA1, 0x00,     /* collection (physical)                                                        */\
    0x05, 0x09,     /*   usage page (buttons). Global item, applies to all subsequent items         */\
    0x19, 0x01,     /*   usage minimum (1)                                                          */\
    0x29, 0x08,     /*   usage maximum (8)                                                          */\
    0x15, 0x00,     /*   logical minimum (0)                                                        */\
    0x25, 0x01,     /*   logical maximum (1)                                                        */\
    0x95, 0x08,     /*   report count (8)                                                           */\
    0x75, 0x01,     /*   report size (1)                                                            */\
    0x81, 0x02,     /*   input (data, var, abs)                                                     */\
    0x05, 0x01,     /*   usage page (generic desktop). Global item, applies to all subsequent items */\
    0x15, 0x81,     /*   logical minimum (-127)                                                     */\
    0x25, 0x7F,     /*   logical maximum (127)                                                      */\
    0x75, 0x08,     /*   report size (8)                                                            */\
    0x09, 0x30,     /*   usage (X)                                                                  */\
    0x09, 0x31,     /*   usage (Y)                                                                  */\
    0x09, 0x38,     /*   usage wheel                                                                */\
    0x95, 0x03,     /*   report count (3)                                                           */\
    0x81, 0x06,     /*   input (3 position bytes X, Y & roller)                                     */\
    0xC0,           /* end collection                                                               */\
    0xC0            /* End Collection                                                               */


static const uint8_t get_descriptor_device[] = {
    USBD_DEVICE_DESCRIPTOR
};

static const uint8_t get_descriptor_configuration[] = {
    USBD_CONFIG_DESCRIPTOR,
    USBD_INTERFACE0_DESCRIPTOR,
    USBD_HID0_DESCRIPTOR,
    USBD_ENDPOINT1_DESCRIPTOR
};
static const uint8_t get_descriptor_string_lang[] = {
    USBD_STRING_LANG
};
static const uint8_t get_descriptor_string_manuf[] = {
    USBD_STRING_MANUFACTURER
};
static const uint8_t get_descriptor_string_prod[] = {
    USBD_STRING_PRODUCT
};
static const uint8_t get_descriptor_report_interface_0[] = {
    USBD_MOUSE_REPORT_DESCRIPTOR
};

static const uint8_t get_config_resp_configured[]   = {1};
static const uint8_t get_config_resp_unconfigured[] = {0};

static const uint8_t get_status_device_resp[]    = {1, 0}; //LSB first: self-powered, no remoteWk
static const uint8_t get_status_interface_resp[] = {0, 0};
static const uint8_t get_status_ep_halted_resp[] = {1, 0};
static const uint8_t get_status_ep_active_resp[] = {0, 0};


#define GET_CONFIG_DESC_SIZE    sizeof(get_descriptor_configuration)
#define GET_INTERFACE_DESC_SIZE 9
#define GET_HID_DESC_SIZE       9
#define GET_ENDPOINT_DESC_SIZE  7

#define get_descriptor_interface_0 \
    &get_descriptor_configuration[9]
#define get_descriptor_hid_0       \
    &get_descriptor_configuration[9+GET_INTERFACE_DESC_SIZE]
#define get_descriptor_endpoint_1  \
    &get_descriptor_configuration[9+GET_INTERFACE_DESC_SIZE+GET_HID_DESC_SIZE]

/**
 * @brief USB configured flag
 *
 * The flag that is used to mark the fact that USB is configured and ready
 * to transmit data
 */
static volatile bool m_usbd_configured = false;

/**
 * @brief Current mouse position
 *
 * The index of current mouse position that would be changed to real offset.
 */
static volatile uint8_t m_mouse_position = 0;

/**
 * @brief The flag for mouse position send pending
 *
 * Setting this flag means that USB endpoint is busy by sending
 * last mouse position.
 */
static volatile bool m_send_mouse_position = false;

/**
 * @brief System OFF request flag
 *
 * This flag is used in button event processing and marks the fact that
 * system OFF should be activated from main loop.
 */
static volatile bool m_system_off_req = false;

/**
 * @name Processing setup requests
 *
 * @{
 */
/**
 * @brief Respond on ep 0
 *
 * Auxiliary function for sending respond on endpoint 0
 * @param[in] p_setup Pointer to setup data from current setup request.
 *                    It would be used to calculate the size of data to send.
 * @param[in] p_data  Pointer to the data to send.
 * @param[in] size    Number of bytes to send.
 * @note Data pointed by p_data has to be available till the USBD_EVT_BUFREADY event.
 */
static void respond_setup_data(
    nrf_drv_usbd_setup_t const * const p_setup,
    void const * p_data, size_t size)
{
    /* Check the size against required response size */
    if(size > p_setup->wLength)
    {
        size = p_setup->wLength;
    }
    ret_code_t ret;
    nrf_drv_usbd_transfer_t transfer =
    {
        .p_data = {.tx = p_data},
        .size = size
    };
    ret = nrf_drv_usbd_ep_transfer(NRF_DRV_USBD_EPIN0, &transfer, NULL);
    if(ret != NRF_SUCCESS)
    {
        NRF_LOG_ERROR("Transfer failed: %08x", (uint32_t)ret);
    }
    ASSERT(ret == NRF_SUCCESS);
    UNUSED_VARIABLE(ret);
}


/** React to GetStatus */
static void usbd_setup_GetStatus(nrf_drv_usbd_setup_t const * const p_setup)
{
    switch(p_setup->bmRequestType)
    {
    case 0x80: // Device
        if(m_usbd_configured)
        {
            if(((p_setup->wIndex) & 0xff) == 0)
            {
                respond_setup_data(
                    p_setup,
                    get_status_device_resp,
                    sizeof(get_status_device_resp));
                return;
            }
        }
        else
        {
            if(((p_setup->wIndex) & 0xff) == 0)
            {
                respond_setup_data(
                    p_setup,
                    get_status_device_resp,
                    sizeof(get_status_device_resp));
                return;
            }
        }
        break;
    case 0x81: // Interface
        if(m_usbd_configured) // Respond only if configured
        {
            if(((p_setup->wIndex) & 0xff) == 0) // Only interface 0 supported
            {
                respond_setup_data(
                    p_setup,
                    get_status_interface_resp,
                    sizeof(get_status_interface_resp));
                return;
            }
        }
        break;
    case 0x82: // Endpoint
        if(((p_setup->wIndex) & 0xff) == 0) // Endpoint 0
        {
            respond_setup_data(
                p_setup,
                get_status_ep_active_resp,
                sizeof(get_status_ep_active_resp));
            return;
        }
        if(m_usbd_configured) // Other endpoints responds if configured
        {
            if(((p_setup->wIndex) & 0xff) == NRF_DRV_USBD_EPIN1)
            {
                if(nrf_drv_usbd_ep_stall_check(NRF_DRV_USBD_EPIN1))
                {
                    respond_setup_data(
                        p_setup,
                        get_status_ep_halted_resp,
                        sizeof(get_status_ep_halted_resp));
                    return;
                }
                else
                {
                    respond_setup_data(
                        p_setup,
                        get_status_ep_active_resp,
                        sizeof(get_status_ep_active_resp));
                    return;
                }
            }
        }
        break;
    default:
        break; // Just go to stall
    }
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_ClearFeature(nrf_drv_usbd_setup_t const * const p_setup)
{
    if( (p_setup->bmRequestType) == 0x02 ) // standard request, recipient=endpoint
    {
        if(((p_setup->wValue) == 0) && (((p_setup->wIndex) >> 8) == 0))
        {/** @todo RK missing EP0 IN and OUT support */
            if(((p_setup->wIndex) & 0xff) == NRF_DRV_USBD_EPIN1)
            {
                nrf_drv_usbd_ep_stall(NRF_DRV_USBD_EPIN1);
                nrf_drv_usbd_setup_clear();
                return;
            }
        }
    }
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_SetFeature(nrf_drv_usbd_setup_t const * const p_setup)
{
    if( (p_setup->bmRequestType) == 0x02 ) // standard request, recipient=endpoint
    {
        if(((p_setup->wValue) == 0) && (((p_setup->wIndex) >> 8) == 0))
        {/** @todo RK missing EP0 IN and OUT support */
            if(((p_setup->wIndex) & 0xff) == NRF_DRV_USBD_EPIN1)
            {
                nrf_drv_usbd_ep_stall(NRF_DRV_USBD_EPIN1);
                nrf_drv_usbd_setup_clear();
                return;
            }
        }
    }
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_GetDescriptor(nrf_drv_usbd_setup_t const * const p_setup)
{
    //determine which descriptor has been asked for
    switch((p_setup->wValue) >> 8)
    {
    case 1: // Device
        if((p_setup->bmRequestType) == 0x80)
        {
            respond_setup_data(
                p_setup,
                get_descriptor_device,
                sizeof(get_descriptor_device));
            return;
        }
        break;
    case 2: // Configuration
        if((p_setup->bmRequestType) == 0x80)
        {
            respond_setup_data(
                p_setup,
                get_descriptor_configuration,
                GET_CONFIG_DESC_SIZE);
            return;
        }
        break;
    case 3: // String
        if((p_setup->bmRequestType) == 0x80)
        {
            // Select the string
            switch((p_setup->wValue) & 0xFF)
            {
            case USBD_STRING_LANG_IX:
                respond_setup_data(
                    p_setup,
                    get_descriptor_string_lang,
                    sizeof(get_descriptor_string_lang));
                return;
            case USBD_STRING_MANUFACTURER_IX:
                respond_setup_data(
                    p_setup,
                    get_descriptor_string_manuf,
                    sizeof(get_descriptor_string_manuf));
                return;
            case USBD_STRING_PRODUCT_IX:
                respond_setup_data(p_setup,
                    get_descriptor_string_prod,
                    sizeof(get_descriptor_string_prod));
                return;
            default:
                break;
            }
        }
        break;
    case 4: // Interface
        if((p_setup->bmRequestType) == 0x80)
        {
            // Witch interface?
            if((((p_setup->wValue) & 0xFF) == 0))
            {
                respond_setup_data(
                    p_setup,
                    get_descriptor_interface_0,
                    GET_INTERFACE_DESC_SIZE);
                return;
            }
        }
        break;
    case 5: // Endpoint
        if((p_setup->bmRequestType) == 0x80)
        {
            // Witch endpoint?
            if((((p_setup->wValue) & 0xFF) == 1))
            {
                respond_setup_data(
                    p_setup,
                    get_descriptor_endpoint_1,
                    GET_ENDPOINT_DESC_SIZE);
                return;
            }
        }
        break;
    case 0x21: // HID
        if((p_setup->bmRequestType) == 0x81)
        {
            // Witch interface
            if((((p_setup->wValue) & 0xFF) == 0))
            {
                respond_setup_data(
                    p_setup,
                    get_descriptor_hid_0,
                    GET_HID_DESC_SIZE);
                return;
            }
        }
        break;
    case 0x22: // HID report
        if((p_setup->bmRequestType) == 0x81)
        {
            //which interface?
            if((((p_setup->wValue) & 0xFF) == 0))
            {
                respond_setup_data(
                    p_setup,
                    get_descriptor_report_interface_0,
                    sizeof(get_descriptor_report_interface_0));
                return;
            }
        }
        break;
    default:
        break; // Not supported - go to stall
    }

    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_GetConfig(nrf_drv_usbd_setup_t const * const p_setup)
{
    if(m_usbd_configured)
    {
        respond_setup_data(
            p_setup,
            get_config_resp_configured,
            sizeof(get_config_resp_configured));
    }
    else
    {
        respond_setup_data(
            p_setup,
            get_config_resp_unconfigured,
            sizeof(get_config_resp_unconfigured));
    }
}

static void usbd_setup_SetConfig(nrf_drv_usbd_setup_t const * const p_setup)
{
    if (p_setup->bmRequestType == 0x00)
    {
        // accept only 0 and 1
        if(((p_setup->wIndex) == 0) && ((p_setup->wLength) == 0))
        {
            if( (p_setup->wValue) == 1 )
            {
                nrf_drv_usbd_ep_enable(NRF_DRV_USBD_EPIN1);
                m_usbd_configured = true;
                nrf_drv_usbd_setup_clear();
                return;
            }
            else if( (p_setup->wValue) == 0 )
            {
                nrf_drv_usbd_ep_disable(NRF_DRV_USBD_EPIN1);
                m_usbd_configured = false;
                nrf_drv_usbd_setup_clear();
                return;
            }
            else
            {
                // Wrong value
            }
        }
    }
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_SetIdle(nrf_drv_usbd_setup_t const * const p_setup)
{
    if (p_setup->bmRequestType == 0x21)
    {
        //accept any value
        nrf_drv_usbd_setup_clear();
        return;
    }
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_SetInterface(
    nrf_drv_usbd_setup_t const * const p_setup)
{
    //no alternate setting is supported - STALL always
    nrf_drv_usbd_setup_stall();
}

static void usbd_setup_SetProtocol(
    nrf_drv_usbd_setup_t const * const p_setup)
{
    if (p_setup->bmRequestType == 0x21)
    {
        //accept any value
        nrf_drv_usbd_setup_clear();
        return;
    }
    nrf_drv_usbd_setup_stall();
}

/** @} */ /* End of processing setup requests functions */


static void usbd_event_handler(nrf_drv_usbd_evt_t const * const p_event)
{
    switch(p_event->type)
    {
    case NRF_DRV_USBD_EVT_SOF:
        {
            static uint32_t cycle = 0;
            ++cycle;
            if((cycle % (m_usbd_configured ? 500 : 100)) == 0)
            {
                bsp_board_led_invert(LED_USB_STATUS);
            }
            break;
        }
    case NRF_DRV_USBD_EVT_EPTRANSFER:
        if(NRF_DRV_USBD_EPIN1 == p_event->data.eptransfer.ep)
        {
            m_send_mouse_position = false;
        }
        if(NRF_DRV_USBD_EPIN0 == p_event->data.eptransfer.ep)
        {
            if(NRF_USBD_EP_OK == p_event->data.eptransfer.status)
            {
                nrf_drv_usbd_setup_clear();
            }
            else
            {
                nrf_drv_usbd_setup_stall();
            }
        }
        break;
    case NRF_DRV_USBD_EVT_SETUP:
        {
            nrf_drv_usbd_setup_t setup;
            nrf_drv_usbd_setup_get(&setup);
            switch(setup.bmRequest)
            {
            case 0x00: // GetStatus
                usbd_setup_GetStatus(&setup);
                break;
            case 0x01: // CleartFeature
                usbd_setup_ClearFeature(&setup);
                break;
            case 0x03: // SetFeature
                usbd_setup_SetFeature(&setup);
                break;
            case 0x05: // SetAddress
                //nothing to do, handled by hardware; but don't STALL
                break;
            case 0x06: // GetDescriptor
                usbd_setup_GetDescriptor(&setup);
                break;
            case 0x08: // GetConfig
                usbd_setup_GetConfig(&setup);
                break;
            case 0x09: // SetConfig
                usbd_setup_SetConfig(&setup);
                break;
            //HID class
            case 0x0A: // SetIdle
                usbd_setup_SetIdle(&setup);
                break;
            case 0x0B: // SetProtocol or SetInterface
                if (setup.bmRequestType == 0x01) // standard request, recipient=interface
                {
                    usbd_setup_SetInterface(&setup);
                }
                else if (setup.bmRequestType == 0x21) // class request, recipient=interface
                {
                    usbd_setup_SetProtocol(&setup);
                }
                else
                {
                    nrf_drv_usbd_setup_stall();
                }
                break;
            default:
                nrf_drv_usbd_setup_stall();
                return;
            }
            break;
        }
    default:
        break;
    }
}


static void move_mouse_pointer(void)
{
    static uint32_t databuffer;

    if(!m_usbd_configured)
        return;
    if (!m_send_mouse_position)
    {
        switch (m_mouse_position & 0x3)
        {
        case 0:
            /* X = 10, rest all are unchanged */
            databuffer = 0x00000A00;
            break;
        case 1:
            /* Y = 10, rest all are unchanged */
            databuffer = 0x000A0000;
            break;
        case 2:
            /* X = -10, rest all are unchanged */
            databuffer = 0x0000F600;
            break;
        case 3:
            /* Y = -10, rest all are unchanged */
            databuffer = 0x00F60000;
            break;
        }
        m_mouse_position++;

        /* Send data */
        static const nrf_drv_usbd_transfer_t transfer =
        {
            .p_data = {.tx = &databuffer},
            .size = sizeof(databuffer)
        };
        UNUSED_RETURN_VALUE(nrf_drv_usbd_ep_transfer(
            NRF_DRV_USBD_EPIN1,
            &transfer,
            NULL));
        m_send_mouse_position = true;
    }
}

static void power_usb_event_handler(nrf_drv_power_usb_evt_t event)
{
    switch(event)
    {
    case NRF_DRV_POWER_USB_EVT_DETECTED:
        NRF_LOG_INFO("USB power detected\r\n");
        if(!nrf_drv_usbd_is_enabled())
        {
            nrf_drv_usbd_enable();
        }
        break;
    case NRF_DRV_POWER_USB_EVT_REMOVED:
        NRF_LOG_INFO("USB power removed\r\n");
        m_usbd_configured = false;
        m_send_mouse_position = false;
        if(nrf_drv_usbd_is_started())
        {
            nrf_drv_usbd_stop();
        }
        if(nrf_drv_usbd_is_enabled())
        {
            nrf_drv_usbd_disable();
        }
        /* Turn OFF LEDs */
        bsp_board_led_off(LED_USB_STATUS);
        bsp_board_led_off(LED_USB_POWER);
        break;
    case NRF_DRV_POWER_USB_EVT_READY:
        NRF_LOG_INFO("USB ready\r\n");
        bsp_board_led_on(LED_USB_POWER);
        if(!nrf_drv_usbd_is_started())
        {
            nrf_drv_usbd_start(true);
        }
        break;
    default:
        ASSERT(false);
    }
}

static void bsp_evt_handler(bsp_event_t evt)
{
    switch(evt)
    {
    case BSP_EVENT_SYSOFF:
        m_system_off_req = true;
        break;
    default:
        break;
    }
}

static void init_power_clock(void)
{
    ret_code_t ret;
    /* Initializing power and clock */
    ret = nrf_drv_clock_init();
    APP_ERROR_CHECK(ret);
    ret = nrf_drv_power_init(NULL);
    APP_ERROR_CHECK(ret);
    nrf_drv_clock_hfclk_request(NULL);
    nrf_drv_clock_lfclk_request(NULL);
    while(!(nrf_drv_clock_hfclk_is_running() &&
            nrf_drv_clock_lfclk_is_running()))
    {
        /* Just waiting */
    }

    APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);

    /* Avoid warnings if assertion is disabled */
    UNUSED_VARIABLE(ret);
}

static void init_bsp(void)
{
    ret_code_t ret;
    ret = bsp_init(
        BSP_INIT_BUTTONS,
        APP_TIMER_TICKS(100, APP_TIMER_PRESCALER),
        bsp_evt_handler);
    APP_ERROR_CHECK(ret);

    ret = bsp_event_to_button_action_assign(
        BTN_SYSTEM_OFF,
        BSP_BUTTON_ACTION_RELEASE,
        BSP_EVENT_SYSOFF);
    APP_ERROR_CHECK(ret);
    /* Avoid warnings if assertion is disabled */
    UNUSED_VARIABLE(ret);
}

static void log_resetreason(void)
{
    /* Reset reason */
    uint32_t rr = nrf_power_resetreas_get();
    NRF_LOG_INFO("Reset reasons:\r\n");
    if(0 == rr)
    {
        NRF_LOG_INFO("- NONE\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_RESETPIN_MASK))
    {
        NRF_LOG_INFO("- RESETPIN\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_DOG_MASK     ))
    {
        NRF_LOG_INFO("- DOG\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_SREQ_MASK    ))
    {
        NRF_LOG_INFO("- SREQ\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_LOCKUP_MASK  ))
    {
        NRF_LOG_INFO("- LOCKUP\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_OFF_MASK     ))
    {
        NRF_LOG_INFO("- OFF\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_LPCOMP_MASK  ))
    {
        NRF_LOG_INFO("- LPCOMP\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_DIF_MASK     ))
    {
        NRF_LOG_INFO("- DIF\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_NFC_MASK     ))
    {
        NRF_LOG_INFO("- NFC\r\n");
    }
    if(0 != (rr & NRF_POWER_RESETREAS_VBUS_MASK    ))
    {
        NRF_LOG_INFO("- VBUS\r\n");
    }
}

int main(void)
{
    init_power_clock();
    init_bsp();


    UNUSED_RETURN_VALUE(NRF_LOG_INIT(NULL));
    NRF_LOG_INFO("Hello USB!\r\n");
    log_resetreason();
    nrf_power_resetreas_clear(nrf_power_resetreas_get());

    /* USB work starts right here */
    UNUSED_RETURN_VALUE(nrf_drv_usbd_init(usbd_event_handler));

    /* Configure selected size of the packed on EP0 */
    nrf_drv_usbd_ep_max_packet_size_set(NRF_DRV_USBD_EPOUT0, EP0_MAXPACKETSIZE);
    nrf_drv_usbd_ep_max_packet_size_set(NRF_DRV_USBD_EPIN0, EP0_MAXPACKETSIZE);

    /* Configure LED and button */
    bsp_board_leds_init();
    bsp_board_led_on(LED_RUNNING);
    bsp_board_led_on(LED_ACTIVE);


    if(USBD_POWER_DETECTION)
    {
        static const nrf_drv_power_usbevt_config_t config =
        {
            .handler = power_usb_event_handler
        };
        nrf_drv_power_usbevt_init(&config);
    }
    else
    {
        NRF_LOG_INFO("No USB power detection enabled\r\nStarting USB now\r\n");
        nrf_delay_us(STARTUP_DELAY);
        if(!nrf_drv_usbd_is_enabled())
        {
            nrf_drv_usbd_enable();
        }
        /* Wait for regulator power up */
        while(NRF_DRV_POWER_USB_STATE_CONNECTED
              ==
              nrf_drv_power_usbstatus_get())
        {
            /* Just waiting */
        }

        if(NRF_DRV_POWER_USB_STATE_READY == nrf_drv_power_usbstatus_get())
        {
            if(!nrf_drv_usbd_is_started())
            {
                nrf_drv_usbd_start(true);
            }
        }
        else
        {
            nrf_drv_usbd_disable();
        }
    }


    while (true)
    {
        if(m_system_off_req)
        {
            NRF_LOG_INFO("Going to system OFF\r\n");
            NRF_LOG_FLUSH();
            bsp_board_led_off(LED_RUNNING);
            bsp_board_led_off(LED_ACTIVE);
            nrf_power_system_off();
        }
        if(m_usbd_configured)
        {
            if (bsp_board_button_state_get(BTN_MOUSE_MOVE))
            {
                NRF_LOG_INFO("   TX pointer\r\n");
                move_mouse_pointer();
            }
        }
        else if(USBD_POWER_DETECTION)
        {
            NRF_LOG_FLUSH();
            bsp_board_led_off(LED_RUNNING);
            /* Even if we miss an event enabling USB,
             * USB event would wake us up. */
            __WFE();
            /* Clear SEV flag if CPU was woken up by event */
            __SEV();
            __WFE();
            bsp_board_led_on(LED_RUNNING);
        }
        else
        {
            /* Nothing to do */
        }
        UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
    }
}
