// Week 11 — ESP-NOW receiver (Board 2, XIAO ESP32-C3)

#include <esp_now.h>
#include <WiFi.h>

const int ledPin  = D1;
const int ledPin2 = D2;
const unsigned long LED_ON_MS = 500;

typedef struct {
  uint8_t pressCount;
} Message;

void pulseLeds(bool led1On, bool led2On) {
  digitalWrite(ledPin, led1On ? HIGH : LOW);
  digitalWrite(ledPin2, led2On ? HIGH : LOW);
  delay(LED_ON_MS);
  digitalWrite(ledPin, LOW);
  digitalWrite(ledPin2, LOW);
}

void OnDataRecv(const uint8_t *mac, const uint8_t *data, int len) {
  Message incoming;
  memcpy(&incoming, data, sizeof(incoming));
  int phase = incoming.pressCount % 3;

  Serial.print(F("Received press #"));
  Serial.println(incoming.pressCount);

  if (phase == 1) {
    pulseLeds(true, false);
  } else if (phase == 2) {
    pulseLeds(false, true);
  } else {
    pulseLeds(true, true);
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  digitalWrite(ledPin, LOW);
  digitalWrite(ledPin2, LOW);

  Serial.println(F("=== ESP-NOW Receiver ==="));
  Serial.print(F("Receiver MAC: "));
  Serial.println(WiFi.macAddress());

  WiFi.mode(WIFI_STA);
  delay(100);

  if (esp_now_init() != ESP_OK) {
    Serial.println(F("ESP-NOW init failed"));
    return;
  }
  esp_now_register_recv_cb(OnDataRecv);

  Serial.println(F("Ready to receive ESP-NOW messages"));
}

void loop() {
  delay(10);
}