#include <wiringPi.h>
#include <wiringPiSPI.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <libconfig.h>
#include <math.h>
#include <time.h>

#include "LS7366R.h"
#include "ringbuffer.h"
#include "led.h"
#include "logging.h"


extern char VERSION[];
extern uint32_t REFCNT;

const int CTRL_OUT = 16;
const int INTR_IN  = 19;
const int SPI_CHAN = 0;
const int SPI_SPEED = 1000000;

const uint32_t PRECISION = 1000;
const uint32_t COUNTER_FREQUENCY = 1e6;

config_t cfg;



void isr() {
  static uint32_t lastCounter = 0;

  uint32_t currentCounter = ls7366rReadOTR();

  uint32_t diff = currentCounter - lastCounter;
  lastCounter = currentCounter;

  ringbufferPut(diff);
  led(E_GREEN, true);
}

void init() {
  wiringPiSetupGpio();

  wiringPiSPISetup(SPI_CHAN, SPI_SPEED);

  pinMode(CTRL_OUT, OUTPUT);
  digitalWrite(CTRL_OUT, 0);

  pinMode(INTR_IN, INPUT);
}

void readConfig() {
  config_init(&cfg);
  if (! config_read_file(&cfg, "/opt/etc/counter.cfg")) {
    logmsg(LOG_ERR, "failed to read config file: %s:%d - %s\n",
        config_error_file(&cfg), config_error_line(&cfg),
        config_error_text(&cfg));
    config_destroy(&cfg);
    exit(-1);
  }
}

void start() {
  wiringPiISR(INTR_IN, INT_EDGE_RISING, isr);
}

int main (void) {
  fprintf(stderr, "VERSION: %s, REFCNT: %u\n", VERSION, REFCNT);

  readConfig();
  init();
  ledInit();
  ls7366rInit(SPI_CHAN);
  start();

  uint8_t ledTick = 0;  
  struct timespec timestamp;
  uint32_t last_seconds = 0;
  uint32_t last_milliseconds = 0;
  uint32_t mainsCntSum = 0;
  uint32_t mainsCntCnt = 0;

  while (1) {
    uint32_t period = ringbufferGet();
  
    clock_gettime(CLOCK_REALTIME, &timestamp);
    uint32_t current_seconds = timestamp.tv_sec;
    uint32_t current_milliseconds = timestamp.tv_nsec / 1e6;
    uint32_t duration = ((current_seconds - last_seconds) * 1000) + (current_milliseconds - last_milliseconds);
    // logmsg(LOG_DEBUG, "s: %lu, ns: %lu, d: %lu, p: %lu", current_seconds, current_milliseconds, duration, period);

    mainsCntSum += period;
    mainsCntCnt += 1;

    if (duration >= 1000) {
      logmsg(LOG_DEBUG, "one second is over");
      last_seconds = current_seconds;
      last_milliseconds = current_milliseconds;

      uint32_t cnt = mainsCntSum / mainsCntCnt;
      mainsCntSum = 0;
      mainsCntCnt = 0;
      uint32_t freq = PRECISION * COUNTER_FREQUENCY / cnt;

      logmsg(LOG_DEBUG, "s: %lu, f: %lu", current_seconds, freq);

    }

    

    ledTick++;
    if (ledTick == 50) {
      ledTick = 0;
      led(E_GREEN, false);
    }

  }

  // will never be reached
  config_destroy(&cfg);
}