#include <Wire.h>
#include "MAX30105.h"
#include "heartRate.h"

MAX30105 sensor;

#define SDA_PIN D4
#define SCL_PIN D5
#define LED_PIN D6   // XIAO ESP32-C3 output LED pin

long lastBeat = 0;
float beatsPerMinute = 0;

void setup() {
  Serial.begin(115200);
  delay(1000);

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  Wire.begin(SDA_PIN, SCL_PIN);

  if (!sensor.begin(Wire, I2C_SPEED_STANDARD)) {
    Serial.println("Sensor not found. Check wiring.");
    while (1);
  }

  sensor.setup();
  sensor.setPulseAmplitudeRed(0x1F);
  sensor.setPulseAmplitudeIR(0x1F);
  sensor.setPulseAmplitudeGreen(0);

  Serial.println("Place your fingertip on the sensor.");
}

void loop() {
  long irValue = sensor.getIR();

  if (irValue > 5000) {
    if (checkForBeat(irValue)) {
      long delta = millis() - lastBeat;
      lastBeat = millis();

      beatsPerMinute = 60.0 / (delta / 1000.0);

      Serial.print("Beat detected! BPM: ");
      Serial.println(beatsPerMinute);

      digitalWrite(LED_PIN, HIGH);
      delay(80);
      digitalWrite(LED_PIN, LOW);
    }
  } else {
    Serial.println("No finger detected");
    digitalWrite(LED_PIN, LOW);
  }

  delay(20);
}