#include "project.h"

#define J2(a,b) a ## b
#define J3(a,b,c) a ## b ## c

#define P1 (GPIO4)
#define P1_PORT GPIOE

#define T_BIT 2
#define T_PORT GPIOE
#define T_EXTI_LINE T_BIT



#define M_T(a) J2(GPIO,a)
#define T M_T(T_BIT)
#define M_EXTI_T(a) J2(EXTI,a)
#define EXTI_T M_EXTI_T(T_EXTI_LINE)
#define M_exti_t_isr(a) J3(exti,a,_isr)
#define exti_t_isr M_exti_t_isr(T_EXTI_LINE)
#define M_NVIC_EXTI_T_IRQ(a) J3(NVIC_EXTI,a,_IRQ)
#define NVIC_EXTI_T_IRQ M_NVIC_EXTI_T_IRQ(T_EXTI_LINE)


static Event_ring dcf77_ring;

static EPOCH dcf77_time;

static uint64_t dcf77_last_second;
uint64_t dcf77_last_happy;

static char dcf77_info[40];

void exti_t_isr (void)
{
  uint32_t now = HW_CLOCK_REG;
  int v;

  v = !!gpio_get (T_PORT, T);

  nvic_disable_irq (NVIC_EXTI_T_IRQ);

  exti_reset_request (EXTI_T);

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

  nvic_enable_irq (NVIC_EXTI_T_IRQ);

}

static uint8_t bits[60];


static void process_bits (uint64_t abs, uint64_t ptp)
{
  UTC u;
  EPOCH e;


  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;



  e = time_utc_to_epoch (u);



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

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


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

  dcf77_time = e;

  dcf77_last_happy = make_happy (abs, 60);

  pll_set_offset (e, abs, ptp);




  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: ", e, dcf77_info);

  meteotime_save (&u, bits);

  dump_bits ("dcf77", bits);
}


static void report_bit (uint64_t abs, uint64_t ptp, 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, ptp);

}


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;
  uint64_t ptp;
  int v;

  led2_set (!!gpio_get (T_PORT, T));



  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;
  ptp = dcf77_ring.events[dcf77_ring.rx_ptr].ptp;


  //led2_set(v);

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

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

    last_1 = now;

    if (pulse_w > 300)  {
      last_s = now;
      is_s = 1;
      second++;
      dcf77_time.s++;
    }

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

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

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


    sprintf (dcf77_info, "m=%d s=%02d b=%d", had_m, second, bit);

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

    last_0 = now;
  }

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

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

    pll_dispatch (dcf77_last_happy, abs, ptp, "DCF77");

    report_time ("DCF", dcf77_time, abs, dcf77_info);
  }


}



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


  gpio_set (P1_PORT, P1);
  delay_ms (50);
  gpio_clear (P1_PORT, P1);

  exti_select_source (EXTI_T, T_PORT);
  exti_set_trigger (EXTI_T, EXTI_TRIGGER_BOTH);
  exti_enable_request (EXTI_T);

  nvic_enable_irq (NVIC_EXTI_T_IRQ);
}