#include <WiFi.h> 
#include <HTTPClient.h> //
#include <UrlEncode.h>

// Buzzer
const int Buzzer_Pin = 35;

// 超声波
const int TrigPin = 5;
const int EchoPin = 18;
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701
long duration;
float DistanceCm;

// WiFi Credentials
const char* ssid = "Wokwi-GUEST"; //定义WiFi网络
const char* password = ""; //需要输入密码，没有东西则不用

// WhatsApp API配置
String phoneNumber = "85259828641";  // WhatsApp手机号码
String apiKey = "8508860";           // API密钥

// 发送WhatsApp信息的函数
void sendMessage(String message) {
  // 拼接URL
  String url = "https://api.callmebot.com/whatsapp.php?phone=" + phoneNumber + "&apikey=" + apiKey + "&text=" + urlEncode(message);
  HTTPClient http;
  http.begin(url);

  // 指定内容类型
  http.addHeader("Content-Type", "application/x-www-form-urlencoded");

  // 发送HTTP POST请求
  int httpResponseCode = http.POST(url);

  if (httpResponseCode == 200) {
    Serial.print("Message sent successfully");
  } else {
    Serial.println("Error sending the message");
    Serial.print("HTTP response code: ");
    Serial.println(httpResponseCode);
  }

  // 释放HTTPClient资源
  http.end();
}

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

  // 初始化超声波传感器引脚
  pinMode(TrigPin, OUTPUT);
  pinMode(EchoPin, INPUT);

  // 连接WiFi
  WiFi.begin(ssid, password);
  Serial.println("Connecting");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.print("Connected to WiFi network with IP Address: ");
  Serial.println(WiFi.localIP());
}

void loop() {

  // 超声波检测距离
  digitalWrite(TrigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(TrigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(TrigPin, LOW);

  // 计算距离
  duration = pulseIn(EchoPin, HIGH);
  DistanceCm = duration * SOUND_SPEED / 2;

  // 如果距离大于15cm，发送更换厕纸信息
  if (DistanceCm > 15) {
    sendMessage("厕所需要更换厕纸");
    delay(5000); // 防止重复发送，延迟5秒
  }
}