/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Ha Thach for Adafruit Industries
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * -# Receive start data packet.
 * -# Based on start packet, prepare NVM area to store received data.
 * -# Receive data packet.
 * -# Validate data packet.
 * -# Write Data packet to NVM.
 * -# If not finished - Wait for next packet.
 * -# Receive stop data packet.
 * -# Activate Image, boot application.
 *
 */
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <stddef.h>

#include "nrfx.h"
#include "nrf_clock.h"
#include "nrfx_power.h"
#include "nrfx_pwm.h"

#include "nordic_common.h"
#include "sdk_common.h"
#include "dfu_transport.h"
#include "bootloader.h"
#include "bootloader_util.h"

#include "nrf.h"
#include "nrf_soc.h"
#include "nrf_nvic.h"
#include "app_error.h"
#include "nrf_gpio.h"
#include "ble.h"
#include "nrf.h"
#include "ble_hci.h"
#include "app_scheduler.h"
#include "nrf_error.h"

#include "boards.h"
#include "uf2/uf2.h"

#include "pstorage_platform.h"
#include "nrf_mbr.h"
#include "pstorage.h"
#include "nrfx_nvmc.h"


#ifdef NRF_USBD
#include "nrf_usbd.h"
#include "tusb.h"

void usb_init(bool cdc_only);
void usb_teardown(void);

#else

#define usb_init(x)       led_state(STATE_USB_MOUNTED) // mark nrf52832 as mounted
#define usb_teardown()

#endif

/*
 * Blinking patterns:
 * - DFU Serial     : LED Status blink
 * - DFU OTA        : LED Status & Conn blink at the same time
 * - DFU Flashing   : LED Status blink 2x fast
 * - Factory Reset  : LED Status blink 2x fast
 * - Fatal Error    : LED Status & Conn blink one after another
 */

/* Magic that written to NRF_POWER->GPREGRET by application when it wish to go into DFU
 * - BOOTLOADER_DFU_OTA_MAGIC used by BLEDfu service : SD is already init
 * - BOOTLOADER_DFU_OTA_FULLRESET_MAGIC entered by soft reset : SD is not init
 * - BOOTLOADER_DFU_SERIAL_MAGIC entered by soft reset : SD is not init
 *
 * Note: for DFU_MAGIC_OTA_APPJUM Softdevice must not initialized.
 * since it is already in application. In all other case of OTA SD must be initialized
 */
#define DFU_MAGIC_OTA_APPJUM            BOOTLOADER_DFU_START             // 0xB1
#define DFU_MAGIC_OTA_RESET             0xA8
#define DFU_MAGIC_SERIAL_ONLY_RESET     0x4e
#define DFU_MAGIC_UF2_RESET             0x57

#define DFU_DBL_RESET_MAGIC             0x5A1AD5      // SALADS
#define DFU_DBL_RESET_APP               0x4ee5677e
#define DFU_DBL_RESET_DELAY             500
#define DFU_DBL_RESET_MEM               0x20007F7C

#define BOOTLOADER_VERSION_REGISTER     NRF_TIMER2->CC[0]
#define DFU_SERIAL_STARTUP_INTERVAL     1000

#define APP_ASKS_FOR_SINGLE_TAP_RESET() (*((uint32_t*)(USER_FLASH_START + 0x200)) == 0x87eeb07c)

// These value must be the same with one in dfu_transport_ble.c
#define BLEGAP_EVENT_LENGTH             6
#define BLEGATT_ATT_MTU_MAX             247
enum { BLE_CONN_CFG_HIGH_BANDWIDTH = 1 };

// Adafruit for factory reset
#define APPDATA_ADDR_START              (BOOTLOADER_REGION_START-DFU_APP_DATA_RESERVED)

#ifdef NRF52840_XXAA
  // Flash 1024 KB
  STATIC_ASSERT( APPDATA_ADDR_START == 0xED000);

#else
  // Flash 512 KB
  STATIC_ASSERT( APPDATA_ADDR_START == 0x6D000);
#endif


void adafruit_factory_reset(void);
static uint32_t softdev_init(bool init_softdevice);

uint32_t* dbl_reset_mem = ((uint32_t*)  DFU_DBL_RESET_MEM );

// true if ble, false if serial
bool _ota_dfu = false;
bool _ota_connected = false;

bool is_ota(void)
{
  return _ota_dfu;
}

void softdev_mbr_init(void)
{
  sd_mbr_command_t com = { .command = SD_MBR_COMMAND_INIT_SD };
  sd_mbr_command(&com);
}

int main(void)
{
  // SD is already Initialized in case of BOOTLOADER_DFU_OTA_MAGIC
  bool sd_inited = (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_APPJUM);

  // Start Bootloader in BLE OTA mode
  _ota_dfu = (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_APPJUM) || (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_RESET);

  // Serial only mode
  bool serial_only_dfu = (NRF_POWER->GPREGRET == DFU_MAGIC_SERIAL_ONLY_RESET);

  // start either serial, uf2 or ble
  bool dfu_start = _ota_dfu || serial_only_dfu || (NRF_POWER->GPREGRET == DFU_MAGIC_UF2_RESET) ||
                    (((*dbl_reset_mem) == DFU_DBL_RESET_MAGIC) && (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk));

  // Clear GPREGRET if it is our values
  if (dfu_start) NRF_POWER->GPREGRET = 0;

  // Save bootloader version to pre-defined register, retrieved by application
  BOOTLOADER_VERSION_REGISTER = (MK_BOOTLOADER_VERSION);

  // This check ensures that the defined fields in the bootloader corresponds with actual setting in the chip.
  APP_ERROR_CHECK_BOOL(*((uint32_t *)NRF_UICR_BOOT_START_ADDRESS) == BOOTLOADER_REGION_START);

  board_init();
  bootloader_init();

  led_state(STATE_BOOTLOADER_STARTED);

  // When updating SoftDevice, bootloader will reset before swapping SD
  if (bootloader_dfu_sd_in_progress())
  {
    led_state(STATE_WRITING_STARTED);

    APP_ERROR_CHECK( bootloader_dfu_sd_update_continue() );
    APP_ERROR_CHECK( bootloader_dfu_sd_update_finalize() );

    led_state(STATE_WRITING_FINISHED);
  }

  /*------------- Determine DFU mode (Serial, OTA, FRESET or normal) -------------*/
  // DFU button pressed
  dfu_start  = dfu_start || button_pressed(BUTTON_DFU);

  // DFU + FRESET are pressed --> OTA
  _ota_dfu = _ota_dfu  || ( button_pressed(BUTTON_DFU) && button_pressed(BUTTON_FRESET) ) ;

  bool const valid_app = bootloader_app_is_valid(DFU_BANK_0_REGION_START);
  bool const just_start_app = valid_app && !dfu_start && (*dbl_reset_mem) == DFU_DBL_RESET_APP;

  if (!just_start_app && APP_ASKS_FOR_SINGLE_TAP_RESET())
    dfu_start = 1;

  // App mode: register 1st reset and DFU startup (nrf52832)
  if ( ! (just_start_app || dfu_start || !valid_app) )
  {
    // Register our first reset for double reset detection
    (*dbl_reset_mem) = DFU_DBL_RESET_MAGIC;

#ifdef NRF52832_XXAA
    /* Even DFU is not active, we still force an 1000 ms dfu serial mode when startup
     * to support auto programming from Arduino IDE
     *
     * Note: Supposedly during this time if RST is press, it will count as double reset.
     * However Double Reset WONT work with nrf52832 since its SRAM got cleared anyway.
     */
    bootloader_dfu_start(false, DFU_SERIAL_STARTUP_INTERVAL);
#else
    // if RST is pressed during this delay --> if will enter dfu
    NRFX_DELAY_MS(DFU_DBL_RESET_DELAY);
#endif
  }

  if (APP_ASKS_FOR_SINGLE_TAP_RESET())
    (*dbl_reset_mem) = DFU_DBL_RESET_APP;
  else
    (*dbl_reset_mem) = 0;

  if ( dfu_start || !valid_app )
  {
    if ( _ota_dfu )
    {
      led_state(STATE_BLE_DISCONNECTED);
      softdev_init(!sd_inited);
      sd_inited = true;
    }
    else
    {
      led_state(STATE_USB_UNMOUNTED);
      usb_init(serial_only_dfu);
    }

    // Initiate an update of the firmware.
    APP_ERROR_CHECK( bootloader_dfu_start(_ota_dfu, 0) );

    if ( _ota_dfu )
    {
      sd_softdevice_disable();
    }else
    {
      usb_teardown();
    }
  }

  // Adafruit Factory reset
  if ( !button_pressed(BUTTON_DFU) && button_pressed(BUTTON_FRESET) )
  {
    adafruit_factory_reset();
  }

  // Reset Board
  board_teardown();

  // Jump to application if valid
  if (bootloader_app_is_valid(DFU_BANK_0_REGION_START) && !bootloader_dfu_sd_in_progress())
  {
    // MBR must be init before start application
    if ( !sd_inited ) softdev_mbr_init();

    // clear in case we kept DFU_DBL_RESET_APP there
    (*dbl_reset_mem) = 0;

    // Select a bank region to use as application region.
    // @note: Only applications running from DFU_BANK_0_REGION_START is supported.
    bootloader_app_start(DFU_BANK_0_REGION_START);
  }

  NVIC_SystemReset();
}


// Perform factory reset to erase Application + Data
void adafruit_factory_reset(void)
{
  led_state(STATE_FACTORY_RESET_STARTED);

  // clear all App Data if any
  if ( DFU_APP_DATA_RESERVED )
  {
    nrfx_nvmc_page_erase(APPDATA_ADDR_START);
  }

  // Only need to erase the 1st page of Application code to make it invalid
  nrfx_nvmc_page_erase(DFU_BANK_0_REGION_START);

  // back to normal
  led_state(STATE_FACTORY_RESET_FINISHED);
}

/**
 * Initializes the SoftDevice and the BLE event interrupt.
 * @param[in] init_softdevice  true if SoftDevice should be initialized. The SoftDevice must only
 *                             be initialized if a chip reset has occured. Soft reset (jump ) from
 *                             application must not reinitialize the SoftDevice.
 */
static uint32_t softdev_init(bool init_softdevice)
{
  if (init_softdevice) softdev_mbr_init();

  // map vector table to bootloader address
  APP_ERROR_CHECK( sd_softdevice_vector_table_base_set(BOOTLOADER_REGION_START) );

  // Enable Softdevice, Use Internal OSC to compatible with all boards
  nrf_clock_lf_cfg_t clock_cfg =
  {
      .source       = NRF_CLOCK_LF_SRC_RC,
      .rc_ctiv      = 16,
      .rc_temp_ctiv = 2,
      .accuracy     = NRF_CLOCK_LF_ACCURACY_250_PPM
  };

  APP_ERROR_CHECK( sd_softdevice_enable(&clock_cfg, app_error_fault_handler) );
  sd_nvic_EnableIRQ(SD_EVT_IRQn);

  /*------------- Configure BLE params  -------------*/
  extern uint32_t  __data_start__[]; // defined in linker
  uint32_t ram_start = (uint32_t) __data_start__;

  ble_cfg_t blecfg;

  // Configure the maximum number of connections.
  varclr(&blecfg);
  blecfg.gap_cfg.role_count_cfg.adv_set_count = 1;
  blecfg.gap_cfg.role_count_cfg.periph_role_count  = 1;
  blecfg.gap_cfg.role_count_cfg.central_role_count = 0;
  blecfg.gap_cfg.role_count_cfg.central_sec_count  = 0;
  APP_ERROR_CHECK( sd_ble_cfg_set(BLE_GAP_CFG_ROLE_COUNT, &blecfg, ram_start) );

  // NRF_DFU_BLE_REQUIRES_BONDS
  varclr(&blecfg);
  blecfg.gatts_cfg.service_changed.service_changed = 1;
  APP_ERROR_CHECK( sd_ble_cfg_set(BLE_GATTS_CFG_SERVICE_CHANGED, &blecfg, ram_start) );

  // ATT MTU
  varclr(&blecfg);
  blecfg.conn_cfg.conn_cfg_tag = BLE_CONN_CFG_HIGH_BANDWIDTH;
  blecfg.conn_cfg.params.gatt_conn_cfg.att_mtu = BLEGATT_ATT_MTU_MAX;
  APP_ERROR_CHECK( sd_ble_cfg_set(BLE_CONN_CFG_GATT, &blecfg, ram_start) );

  // Event Length + HVN queue + WRITE CMD queue setting affecting bandwidth
  varclr(&blecfg);
  blecfg.conn_cfg.conn_cfg_tag = BLE_CONN_CFG_HIGH_BANDWIDTH;
  blecfg.conn_cfg.params.gap_conn_cfg.conn_count   = 1;
  blecfg.conn_cfg.params.gap_conn_cfg.event_length = BLEGAP_EVENT_LENGTH;
  APP_ERROR_CHECK( sd_ble_cfg_set(BLE_CONN_CFG_GAP, &blecfg, ram_start) );

  // Enable BLE stack.
  // Note: Interrupt state (enabled, forwarding) is not work properly if not enable ble
  APP_ERROR_CHECK( sd_ble_enable(&ram_start) );

#if 0
  ble_opt_t  opt;
  varclr(&opt);
  opt.common_opt.conn_evt_ext.enable = 1; // enable Data Length Extension
  APP_ERROR_CHECK( sd_ble_opt_set(BLE_COMMON_OPT_CONN_EVT_EXT, &opt) );
#endif

  return NRF_SUCCESS;
}


//--------------------------------------------------------------------+
// Error Handler
//--------------------------------------------------------------------+
void app_error_fault_handler(uint32_t id, uint32_t pc, uint32_t info)
{
  volatile uint32_t* ARM_CM_DHCSR =  ((volatile uint32_t*) 0xE000EDF0UL); /* Cortex M CoreDebug->DHCSR */
  if ( (*ARM_CM_DHCSR) & 1UL ) __asm("BKPT #0\n"); /* Only halt mcu if debugger is attached */
  NVIC_SystemReset();
}

void assert_nrf_callback (uint16_t line_num, uint8_t const * p_file_name)
{
  app_error_fault_handler(0xDEADBEEF, 0, 0);
}

/*------------------------------------------------------------------*/
/* SoftDevice Event handler
 *------------------------------------------------------------------*/

// Process BLE event from SD
uint32_t proc_ble(void)
{
  __ALIGN(4) uint8_t ev_buf[ BLE_EVT_LEN_MAX(BLEGATT_ATT_MTU_MAX) ];
  uint16_t ev_len = BLE_EVT_LEN_MAX(BLEGATT_ATT_MTU_MAX);

  // Get BLE Event
  uint32_t err = sd_ble_evt_get(ev_buf, &ev_len);

  // Handle valid event, ignore error
  if( NRF_SUCCESS == err)
  {
    ble_evt_t* evt = (ble_evt_t*) ev_buf;

    switch (evt->header.evt_id)
    {
      case BLE_GAP_EVT_CONNECTED:
        _ota_connected = true;
        led_state(STATE_BLE_CONNECTED);
      break;

      case BLE_GAP_EVT_DISCONNECTED:
        _ota_connected = false;
        led_state(STATE_BLE_DISCONNECTED);
      break;

      default: break;
    }

    // from dfu_transport_ble
    extern void ble_evt_dispatch(ble_evt_t * p_ble_evt);
    ble_evt_dispatch(evt);
  }

  return err;
}

// process SOC event from SD
uint32_t proc_soc(void)
{
  uint32_t soc_evt;
  uint32_t err = sd_evt_get(&soc_evt);

  if (NRF_SUCCESS == err)
  {
    pstorage_sys_event_handler(soc_evt);

#ifdef NRF_USBD
    extern void tusb_hal_nrf_power_event(uint32_t event);
    /*------------- usb power event handler -------------*/
    int32_t usbevt = (soc_evt == NRF_EVT_POWER_USB_DETECTED   ) ? NRFX_POWER_USB_EVT_DETECTED:
                     (soc_evt == NRF_EVT_POWER_USB_POWER_READY) ? NRFX_POWER_USB_EVT_READY   :
                     (soc_evt == NRF_EVT_POWER_USB_REMOVED    ) ? NRFX_POWER_USB_EVT_REMOVED : -1;

    if ( usbevt >= 0) tusb_hal_nrf_power_event(usbevt);
#endif
  }

  return err;
}

void ada_sd_task(void* evt_data, uint16_t evt_size)
{
  (void) evt_data;
  (void) evt_size;

  // process BLE and SOC until there is no more events
  while( (NRF_ERROR_NOT_FOUND != proc_ble()) || (NRF_ERROR_NOT_FOUND != proc_soc()) )
  {

  }
}

void SD_EVT_IRQHandler(void)
{
  // Use App Scheduler to defer handling code in non-isr context
  app_sched_event_put(NULL, 0, ada_sd_task);
}