#include "project.h"

#define P1 (GPIO11)
#define P1_PORT GPIOD

#define T (GPIO12)
#define T_PORT GPIOD


static Event_ring dcf77_ring;


uint64_t dcf77_last_second;

void exti15_10_isr (void)
{
  uint32_t now = SCS_DWT_CYCCNT;
  int v;

  v = !!gpio_get (T_PORT, T);

  nvic_disable_irq (NVIC_EXTI15_10_IRQ);
  exti_reset_request (EXTI12);

  dcf77_ring.events[dcf77_ring.tx_ptr].when = now;
  dcf77_ring.events[dcf77_ring.tx_ptr].value = v;
  dcf77_ring.tx_ptr = (dcf77_ring.tx_ptr + 1) & ERING_MASK;

  nvic_enable_irq (NVIC_EXTI15_10_IRQ);
}




static uint8_t bits[60];


static void process_bits (uint64_t abs)
{
  UTC u;
  EPOCH dcf77_time;


  if (bits[0]) return;

  if (!bits[20]) return;

  if (!check_parity (bits, 21, 27, bits[28])) return;

  if (!check_parity (bits, 29, 34, bits[35])) return;

  if (!check_parity (bits, 36, 57, bits[58])) return;

  u.jday = 0;
  u.year = le_bcd (bits, 50, 57);
  u.month = le_bcd (bits, 45, 49);
  u.mday = le_bcd (bits, 36, 41);
  u.hour = le_bcd (bits, 29, 34);
  u.minute = le_bcd (bits, 21, 27);
  u.second = 0;
  u.nanosecond = 0;



  dcf77_time = time_utc_to_epoch (u);


  dcf77_time.s -= 2; /*Message arrives 2s early*/

  dcf77_time.s -= 3600; /*CET*/

  if (bits[17]) dcf77_time.s -= 3600; /*CEST*/

  pll_set_offset (dcf77_time, abs);

  printf ("DCF77: Next minute is: %02d-%02d-%02d %02d:%02d\r\n", u.year, u.month, u.mday, u.hour, u.minute);
  time_print_epoch ("DCF77: ", dcf77_time);

  dump_bits ("dcf77", bits);
}


static void report_bit (uint64_t abs, int second, int b)
{
  if ((second < 0) || (second > 58)) return;

  bits[second] = b;

  //  printf("DCF77: bits[%d]=%d\r\n",second,b);

  if (second == 58) process_bits (abs);

}

static void report_time (uint64_t abs)
{
#if 1
  EPOCH e = pll_decompose (abs);
  time_print_epoch ("DCF77: ", e);
#endif
}


void dcf77_dispatch (void)
{
  static uint32_t last_0, last_1, last_s;
  static int second, bit, had_m;
  uint32_t pulse_w, offset;
  static uint64_t abs;
  int is_s = 0;

  uint32_t now;
  int v;




  if (dcf77_ring.rx_ptr == dcf77_ring.tx_ptr) return;

  v = dcf77_ring.events[dcf77_ring.rx_ptr].value;
  now = dcf77_ring.events[dcf77_ring.rx_ptr].when;

  dcf77_ring.rx_ptr = (dcf77_ring.rx_ptr + 1) & ERING_MASK;

  if (v) {
    pulse_w = now - last_0;
    pulse_w /= (HZ / 1000);

    last_1 = now;

    if (pulse_w > 300)  {
      last_s = now;
      is_s = 1;
      second++;
    }

    if (pulse_w > 1300) {
      had_m = 1;
      second = 0;
    }

  } else {
    pulse_w = now - last_1;
    pulse_w /= (HZ / 1000);

    if (pulse_w > 150)
      bit = 1;
    else
      bit = 0;

    if (had_m)
      report_bit (abs, second, bit);

    last_0 = now;
  }

  offset = now - last_s;
  offset /= (HZ / 1000);

  if (is_s) {
    abs = abs_extend (now);
    dcf77_last_second = abs;

    //pll_dispatch (abs);

    if (time_known)
      report_time (abs);
  }


}



void
dcf77_init (void)
{
  MAP_INPUT (T);
  MAP_OUTPUT_PP (P1);

  gpio_clear (P1_PORT, P1);

  exti_select_source (EXTI12, T_PORT);
  exti_set_trigger (EXTI12, EXTI_TRIGGER_BOTH);
  exti_enable_request (EXTI12);
  nvic_enable_irq (NVIC_EXTI15_10_IRQ);
}