/**************************************************************************/
/*!
    @file     boards.c
    @author   hathach (tinyusb.org)

    @section LICENSE

    Software License Agreement (BSD License)

    Copyright (c) 2018, Adafruit Industries (adafruit.com)
    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 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 the copyright holders nor the
    names of its contributors may be used to endorse or promote products
    derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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 "boards.h"
#include "nrf_pwm.h"
#include "app_scheduler.h"
#include "app_timer.h"

//--------------------------------------------------------------------+
// MACRO TYPEDEF CONSTANT ENUM DECLARATION
//--------------------------------------------------------------------+
#define SCHED_MAX_EVENT_DATA_SIZE           sizeof(app_timer_event_t)        /**< Maximum size of scheduler events. */
#define SCHED_QUEUE_SIZE                    30                               /**< Maximum number of events in the scheduler queue. */

#if defined(LED_NEOPIXEL) || defined(LED_RGB_RED_PIN)
  void neopixel_write(uint8_t *pixels);
#endif

//------------- IMPLEMENTATION -------------//
void board_init(void)
{
  // stop LF clock just in case we jump from application without reset
  NRF_CLOCK->TASKS_LFCLKSTOP = 1UL;

  // Use Internal OSC to compatible with all boards
  NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_RC;
  NRF_CLOCK->TASKS_LFCLKSTART = 1UL;

  button_init(BUTTON_DFU);
  button_init(BUTTON_FRESET);
  NRFX_DELAY_US(100); // wait for the pin state is stable

  // use PMW0 for LED RED
  led_pwm_init(LED_PRIMARY, LED_PRIMARY_PIN);
  #if LEDS_NUMBER > 1
  led_pwm_init(LED_SECONDARY, LED_SECONDARY_PIN);
  #endif

// use neopixel for use enumeration
#if defined(LED_NEOPIXEL) || defined(LED_RGB_RED_PIN)
  extern void neopixel_init(void);
  neopixel_init();
#endif

  // Init scheduler
  APP_SCHED_INIT(SCHED_MAX_EVENT_DATA_SIZE, SCHED_QUEUE_SIZE);

  // Init app timer (use RTC1)
  app_timer_init();

  // Configure Systick for led blinky
  NVIC_SetPriority(SysTick_IRQn, 7);
  SysTick_Config(SystemCoreClock/1000);
}

void board_teardown(void)
{
  // Disable systick, turn off LEDs
  SysTick->CTRL = 0;

  // Disable and reset PWM for LEDs
  led_pwm_teardown();

#if defined(LED_NEOPIXEL) || defined(LED_RGB_RED_PIN)
  extern void neopixel_teardown(void);
  neopixel_teardown();
#endif
  // Button

  // Stop RTC1 used by app_timer
  NVIC_DisableIRQ(RTC1_IRQn);
  NRF_RTC1->EVTENCLR    = RTC_EVTEN_COMPARE0_Msk;
  NRF_RTC1->INTENCLR    = RTC_INTENSET_COMPARE0_Msk;
  NRF_RTC1->TASKS_STOP  = 1;
  NRF_RTC1->TASKS_CLEAR = 1;

  // Stop LF clock
  NRF_CLOCK->TASKS_LFCLKSTOP = 1UL;
}

static uint32_t _systick_count = 0;
void SysTick_Handler(void)
{
  _systick_count++;

  led_tick();
}


uint32_t tusb_hal_millis(void)
{
  return ( ( ((uint64_t)app_timer_cnt_get())*1000*(APP_TIMER_CONFIG_RTC_FREQUENCY+1)) / APP_TIMER_CLOCK_FREQ );
}

void pwm_teardown(NRF_PWM_Type* pwm )
{
  pwm->TASKS_SEQSTART[0] = 0;
  pwm->ENABLE            = 0;

  pwm->PSEL.OUT[0] = 0xFFFFFFFF;
  pwm->PSEL.OUT[1] = 0xFFFFFFFF;
  pwm->PSEL.OUT[2] = 0xFFFFFFFF;
  pwm->PSEL.OUT[3] = 0xFFFFFFFF;

  pwm->MODE        = 0;
  pwm->COUNTERTOP  = 0x3FF;
  pwm->PRESCALER   = 0;
  pwm->DECODER     = 0;
  pwm->LOOP        = 0;
  pwm->SEQ[0].PTR  = 0;
  pwm->SEQ[0].CNT  = 0;
}

static uint16_t led_duty_cycles[PWM0_CH_NUM] = { 0 };

#if LEDS_NUMBER > PWM0_CH_NUM
#error "Only " PWM0_CH_NUM " concurrent status LEDs are supported."
#endif

void led_pwm_init(uint32_t led_index, uint32_t led_pin)
{
  NRF_PWM_Type* pwm    = NRF_PWM0;

  pwm->ENABLE = 0;

  nrf_gpio_cfg_output(led_pin);
  nrf_gpio_pin_write(led_pin, 1 - LED_STATE_ON);

  pwm->PSEL.OUT[led_index] = led_pin;

  pwm->MODE            = PWM_MODE_UPDOWN_Up;
  pwm->COUNTERTOP      = 0xff;
  pwm->PRESCALER       = PWM_PRESCALER_PRESCALER_DIV_16;
  pwm->DECODER         = PWM_DECODER_LOAD_Individual;
  pwm->LOOP            = 0;

  pwm->SEQ[0].PTR      = (uint32_t) (led_duty_cycles);
  pwm->SEQ[0].CNT      = 4; // default mode is Individual --> count must be 4
  pwm->SEQ[0].REFRESH  = 0;
  pwm->SEQ[0].ENDDELAY = 0;

  pwm->ENABLE = 1;

  pwm->EVENTS_SEQEND[0] = 0;
//  pwm->TASKS_SEQSTART[0] = 1;
}

void led_pwm_teardown(void)
{
  pwm_teardown(NRF_PWM0);
}

void led_pwm_duty_cycle(uint32_t led_index, uint16_t duty_cycle)
{
  led_duty_cycles[led_index] = duty_cycle;
  nrf_pwm_event_clear(NRF_PWM0, NRF_PWM_EVENT_SEQEND0);
  nrf_pwm_task_trigger(NRF_PWM0, NRF_PWM_TASK_SEQSTART0);
}

static uint32_t primary_cycle_length;
#ifdef LED_SECONDARY_PIN
static uint32_t secondary_cycle_length;
#endif
void led_tick() {
    uint32_t millis = _systick_count;

    uint32_t cycle = millis % primary_cycle_length;
    uint32_t half_cycle = primary_cycle_length / 2;
    if (cycle > half_cycle) {
        cycle = primary_cycle_length - cycle;
    }
    uint16_t duty_cycle = 0x4f * cycle / half_cycle;
    #if LED_STATE_ON == 1
    duty_cycle = 0xff - duty_cycle;
    #endif
    led_pwm_duty_cycle(LED_PRIMARY, duty_cycle);

    #ifdef LED_SECONDARY_PIN
    cycle = millis % secondary_cycle_length;
    half_cycle = secondary_cycle_length / 2;
    if (cycle > half_cycle) {
        cycle = secondary_cycle_length - cycle;
    }
    duty_cycle = 0x8f * cycle / half_cycle;
    #if LED_STATE_ON == 1
    duty_cycle = 0xff - duty_cycle;
    #endif
    led_pwm_duty_cycle(LED_SECONDARY, duty_cycle);
    #endif
}

static uint32_t rgb_color;
static bool temp_color_active = false;
void led_state(uint32_t state)
{
    uint32_t new_rgb_color = rgb_color;
    uint32_t temp_color = 0;
    switch (state) {
        case STATE_USB_MOUNTED:
          new_rgb_color = 0x00ff00;
          primary_cycle_length = 3000;
          break;

        case STATE_BOOTLOADER_STARTED:
        case STATE_USB_UNMOUNTED:
          new_rgb_color = 0xff0000;
          primary_cycle_length = 300;
          break;

        case STATE_WRITING_STARTED:
          temp_color = 0xff0000;
          primary_cycle_length = 100;
          break;

        case STATE_WRITING_FINISHED:
          // Empty means to unset any temp colors.
          primary_cycle_length = 3000;
          break;

        case STATE_BLE_CONNECTED:
          new_rgb_color = 0x0000ff;
          #ifdef LED_SECONDARY_PIN
          secondary_cycle_length = 3000;
          #else
          primary_cycle_length = 3000;
          #endif
          break;

        case STATE_BLE_DISCONNECTED:
          new_rgb_color = 0xff00ff;
          #ifdef LED_SECONDARY_PIN
          secondary_cycle_length = 300;
          #else
          primary_cycle_length = 300;
          #endif
          break;

        default:
        break;
    }
    uint8_t* final_color = NULL;
    new_rgb_color &= BOARD_RGB_BRIGHTNESS;
    if (temp_color != 0){
        temp_color &= BOARD_RGB_BRIGHTNESS;
        final_color = (uint8_t*)&temp_color;
        temp_color_active = true;
    } else if (new_rgb_color != rgb_color) {
        final_color = (uint8_t*)&new_rgb_color;
        rgb_color = new_rgb_color;
    } else if (temp_color_active) {
        final_color = (uint8_t*)&rgb_color;
    }
    #if LED_NEOPIXEL || defined(LED_RGB_RED_PIN)
    if (final_color != NULL) {
        neopixel_write(final_color);
    }
    #else
    (void) final_color;
    #endif
}

#ifdef LED_NEOPIXEL

// WS2812B (rev B) timing is 0.4 and 0.8 us
#define MAGIC_T0H               6UL | (0x8000) // 0.375us
#define MAGIC_T1H              13UL | (0x8000) // 0.8125us
#define CTOPVAL                20UL            // 1.25us

#define NEO_NUMBYTE  3

static uint16_t pixels_pattern[NEO_NUMBYTE * 8 + 2];

// use PWM1 for neopixel
void neopixel_init(void)
{
  // To support both the SoftDevice + Neopixels we use the EasyDMA
  // feature from the NRF25. However this technique implies to
  // generate a pattern and store it on the memory. The actual
  // memory used in bytes corresponds to the following formula:
  //              totalMem = numBytes*8*2+(2*2)
  // The two additional bytes at the end are needed to reset the
  // sequence.
  NRF_PWM_Type* pwm = NRF_PWM1;

  // Set the wave mode to count UP
  // Set the PWM to use the 16MHz clock
  // Setting of the maximum count
  // but keeping it on 16Mhz allows for more granularity just
  // in case someone wants to do more fine-tuning of the timing.
  nrf_pwm_configure(pwm, NRF_PWM_CLK_16MHz, NRF_PWM_MODE_UP, CTOPVAL);

  // Disable loops, we want the sequence to repeat only once
  nrf_pwm_loop_set(pwm, 0);

  // On the "Common" setting the PWM uses the same pattern for the
  // for supported sequences. The pattern is stored on half-word of 16bits
  nrf_pwm_decoder_set(pwm, PWM_DECODER_LOAD_Common, PWM_DECODER_MODE_RefreshCount);

  // The following settings are ignored with the current config.
  nrf_pwm_seq_refresh_set(pwm, 0, 0);
  nrf_pwm_seq_end_delay_set(pwm, 0, 0);

  // The Neopixel implementation is a blocking algorithm. DMA
  // allows for non-blocking operation. To "simulate" a blocking
  // operation we enable the interruption for the end of sequence
  // and block the execution thread until the event flag is set by
  // the peripheral.
  //    pwm->INTEN |= (PWM_INTEN_SEQEND0_Enabled<<PWM_INTEN_SEQEND0_Pos);

  // PSEL must be configured before enabling PWM
  nrf_pwm_pins_set(pwm, (uint32_t[] ) { LED_NEOPIXEL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL });

  // Enable the PWM
  nrf_pwm_enable(pwm);
}

void neopixel_teardown(void)
{
  uint8_t grb[3] = { 0, 0, 0 };

  NRFX_DELAY_US(50);  // wait for previous write is complete

  neopixel_write(grb);
  NRFX_DELAY_US(50);  // wait for this write

  pwm_teardown(NRF_PWM1);
}

// write 3 bytes color to a built-in neopixel
void neopixel_write (uint8_t *pixels)
{
  uint8_t grb[NEO_NUMBYTE] = {pixels[1], pixels[2], pixels[0]};
  uint16_t pos = 0;    // bit position
  for ( uint16_t n = 0; n < NEO_NUMBYTE; n++ )
  {
    uint8_t pix = grb[n];

    for ( uint8_t mask = 0x80; mask > 0; mask >>= 1 )
    {
      pixels_pattern[pos] = (pix & mask) ? MAGIC_T1H : MAGIC_T0H;
      pos++;
    }
  }

  // Zero padding to indicate the end of sequence
  pixels_pattern[pos++] = 0 | (0x8000);    // Seq end
  pixels_pattern[pos++] = 0 | (0x8000);    // Seq end

  NRF_PWM_Type* pwm = NRF_PWM1;

  nrf_pwm_seq_ptr_set(pwm, 0, pixels_pattern);
  nrf_pwm_seq_cnt_set(pwm, 0, sizeof(pixels_pattern)/2);
  nrf_pwm_event_clear(pwm, NRF_PWM_EVENT_SEQEND0);
  nrf_pwm_task_trigger(pwm, NRF_PWM_TASK_SEQSTART0);

  // blocking wait for sequence complete
  while( !nrf_pwm_event_check(pwm, NRF_PWM_EVENT_SEQEND0) ) {}
  nrf_pwm_event_clear(pwm, NRF_PWM_EVENT_SEQEND0);
}
#endif

#if defined(LED_RGB_RED_PIN) && defined(LED_RGB_GREEN_PIN) && defined(LED_RGB_BLUE_PIN)

#ifdef LED_SECONDARY_PIN
#error "Cannot use secondary LED at the same time as an RGB status LED."
#endif

#define LED_RGB_RED   1
#define LED_RGB_BLUE  2
#define LED_RGB_GREEN 3

void neopixel_init(void)
{
  led_pwm_init(LED_RGB_RED, LED_RGB_RED_PIN);
  led_pwm_init(LED_RGB_GREEN, LED_RGB_GREEN_PIN);
  led_pwm_init(LED_RGB_BLUE, LED_RGB_BLUE_PIN);
}

void neopixel_teardown(void)
{
  uint8_t grb[3] = { 0, 0, 0 };
  neopixel_write(grb);
  nrf_gpio_cfg_default(LED_RGB_RED_PIN);
  nrf_gpio_cfg_default(LED_RGB_GREEN_PIN);
  nrf_gpio_cfg_default(LED_RGB_BLUE_PIN);
}

// write 3 bytes color to a built-in neopixel
void neopixel_write (uint8_t *pixels)
{
  led_pwm_duty_cycle(LED_RGB_RED, pixels[2]);
  led_pwm_duty_cycle(LED_RGB_GREEN, pixels[1]);
  led_pwm_duty_cycle(LED_RGB_BLUE, pixels[0]);
}
#endif