// Week 11 — ESP-NOW sender (Board 1, XIAO ESP32-C3)
// Button D0 — debounced press sends message to Board 2

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

const int buttonPin = D0;
const unsigned long DEBOUNCE_MS = 50;

// 接收端MAC地址
uint8_t receiverMac[] = {0x64, 0xE8, 0x33, 0x85, 0xA7, 0x00};

typedef struct {
  uint8_t pressCount;
} Message;

Message outgoing;
esp_now_peer_info_t peerInfo;

int buttonState = LOW;
int lastReading = LOW;
unsigned long lastDebounceTime = 0;
int pressCount = 0;

void OnDataSent(const uint8_t *mac, esp_now_send_status_t status) {
  Serial.print(F("Send status: "));
  if (status == ESP_NOW_SEND_SUCCESS) {
    Serial.println(F("✅ OK"));
  } else {
    Serial.println(F("❌ FAIL"));
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(buttonPin, INPUT);

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

  // 只设置WiFi模式，不设置信道
  WiFi.mode(WIFI_STA);
  
  // 延迟一下让WiFi初始化
  delay(100);

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

  // 配置peer - 不指定信道
  memcpy(peerInfo.peer_addr, receiverMac, 6);
  peerInfo.channel = 0;  // 0表示自动
  peerInfo.encrypt = false;
  peerInfo.ifidx = WIFI_IF_STA;
  
  if (esp_now_add_peer(&peerInfo) != ESP_OK) {
    Serial.println(F("❌ Failed to add peer"));
    return;
  }

  Serial.println(F("✅ ESP-NOW sender ready"));
  Serial.print(F("Target MAC: "));
  for (int i = 0; i < 6; i++) {
    Serial.printf("%02X", receiverMac[i]);
    if (i < 5) Serial.print(":");
  }
  Serial.println();
}

void loop() {
  int reading = digitalRead(buttonPin);
  if (reading != lastReading) {
    lastDebounceTime = millis();
  }
  if ((millis() - lastDebounceTime) > DEBOUNCE_MS) {
    if (reading != buttonState) {
      buttonState = reading;
      if (buttonState == HIGH) {
        pressCount++;
        outgoing.pressCount = (uint8_t)pressCount;
        
        esp_err_t result = esp_now_send(receiverMac, (uint8_t *)&outgoing, sizeof(outgoing));
        if (result == ESP_OK) {
          Serial.print(F("📤 Sent press #"));
          Serial.println(pressCount);
        } else {
          Serial.print(F("❌ Send error code: "));
          Serial.println(result);
        }
      }
    }
  }
  lastReading = reading;
}