#include <WiFi.h>
#include <ThingSpeak.h>
#include "DHTesp.h"

// WiFi & ThingSpeak
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASS ""
#define CHANNEL_ID 3131689
#define READ_CHANNEL_ID 3131689
#define WRITE_API_KEY "MHZ381ONN2VJZQQO"
#define READ_API_KEY "JPR9FRBRPJ0U85EP"

WiFiClient client;

// Pins
#define DHT_PIN 15
#define TRIG_PIN 14
#define ECHO_PIN 27
#define RELAY_PIN 5

DHTesp dht;
#define READ_FIELD 1 // ThingSpeak field for relay control

void setup() {
  Serial.begin(115200);
  dht.setup(DHT_PIN, DHTesp::DHT22);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);

  Serial.print("Connecting to WiFi...");
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  int retries = 0;
  while (WiFi.status() != WL_CONNECTED && retries < 20) {
    Serial.print(".");
    delay(1000);
    retries++;
  }
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("\n✅ WiFi Connected!");
  } else {
    Serial.println("\n❌ WiFi Failed!");
  }

  ThingSpeak.begin(client);
}

void loop() {
  // --- Read DHT22 ---
  TempAndHumidity data = dht.getTempAndHumidity();
  float temp = data.temperature;
  float hum = data.humidity;

  // --- Read Ultrasonic ---
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000); // 30ms timeout
  float distance = (duration > 0) ? duration * 0.034 / 2 : -1; // -1 if timeout

  // --- Display ---
  Serial.println("=======================");
  Serial.println("🌡 Temp: " + String(temp, 1) + " °C");
  Serial.println("💧 Humidity: " + String(hum, 1) + " %");
  Serial.println("📏 Water Level: " + String(distance, 1) + " cm");

  // --- Upload to ThingSpeak ---
  ThingSpeak.setField(1, hum);
  ThingSpeak.setField(2, temp);
  ThingSpeak.setField(3, distance);

  int code = ThingSpeak.writeFields(CHANNEL_ID, WRITE_API_KEY);
  if (code == 200) {
    Serial.println("✅ Data sent to ThingSpeak");
  } else {
    Serial.println("❌ Error sending data. HTTP code: " + String(code));
  }

  // --- Read Relay Control Key ---
  float controlKey = ThingSpeak.readFloatField(READ_CHANNEL_ID, READ_FIELD, READ_API_KEY);
  Serial.println("🔑 Control Key: " + String(controlKey));

  if (controlKey == 1) {
    digitalWrite(RELAY_PIN, HIGH);
    Serial.println("🔔 Pump ON");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    Serial.println("💤 Pump OFF");
  }

  delay(15000);
}