//iD alarm proof-of-concept
//(C) TechnicallyObsolete 2024


//These times are in microseconds
#define ID_T_RESET 1000
#define ID_T_L1 200

#define ID_T_H_P1 150 //Sample point
#define ID_T_H_P2 50 //Total delay to make up 200us
#define ID_T_L_P1 150
#define ID_T_L_P2 50

typedef enum {
  ALARM_ID_LEVEL_OFF,
  ALARM_ID_LEVEL_RESET,
  ALARM_ID_LEVEL_LOW,
  ALARM_ID_LEVEL_HIGH
} alarmId_level_e;

//Provide these functions
void delay_us(uint16_t us);
uint16_t adc_read(); //Note - adc_read is presumed to be very quick. If it's not, the sample point timing above might need adjusting.
void set_level(alarmId_level_e level);


//Reads up to 32 devices.
//Would be possible to modify to read more, but 30 devices is the common limit for an iD loop.
int read_all(uint32_t deviceCount, uint32_t *alarm, uint32_t *tamper){

  if ((alarm == NULL) || (tamper == NULL)) {
    return ERR_BAD_PARAM;
  }

  if (deviceCount > 32){
    return ERR_BAD_PARAM;
  }

  uint16_t adcLevelsH[32];
  uint16_t adcLevelsL[32];
  uint16_t baseline;
  uint16_t threshold;

  *alarm = 0;
  *tamper = 0;

  set_level(ALARM_ID_LEVEL_RESET);
  delay_us(ID_T_RESET);

  //Measure the baseline level (current draw when not reading) and generate a threshold based on this
  baseline = adc_read();
  threshold = baseline + 100;

  set_level(ALARM_ID_LEVEL_LOW);
  delay_us(ID_T_L1);
  for(uint32_t i = 0; i < deviceCount; i++){
    set_level(ALARM_ID_LEVEL_HIGH);
    delay_us(ID_T_H_P1);

    adcLevelsH[i] = adc_read();

    if (adcLevelsH[i] > threshold){
      *tamper |= (1 << i);
    }
    delay_us(ID_T_H_P2);

    set_level(ALARM_ID_LEVEL_LOW);
    delay_us(ID_T_L_P1);
    adcLevelsL[i] = adc_read();
    if (adcLevelsL[i] > threshold){
      *alarm |= (1 << i);
    }
    delay_us(ID_T_L_P2);
  }

  //Not sure if required but makes debug easier
  set_level(ALARM_ID_LEVEL_OFF);

  for(uint32_t i = 0; i < deviceCount; i++){
    syslog_logFnName(NULL, SYSLOG_LEVEL_INFO, "Slot %d ADC H=%d L=%d", i, adcLevelsH[i], adcLevelsL[i]);
  }

  syslog_logFnName(NULL, SYSLOG_LEVEL_INFO, "Returning: 0x%04X 0x%04X", *tamper, *alarm);
  return ERR_OK;
}


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