// IoT-based Irrigation System for ThingSpeak
// Based on ESP32 WOKWI Simulator by ThinkIOT
// ThingSpeak channel can be found here: https://thingspeak.com/channels/2383114

#include <WiFi.h>
#include <WebServer.h>
#include "ThingSpeak.h"
#include "DHT.h"

/************ PIN DEFINITIONS ************/
#define SOIL_MOISTURE_PIN 34
#define SPRINKLER_CONTROL_PIN 19
#define DHTPIN 4
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

/************ WIFI ************/
const char* WIFI_NAME = "Wokwi-GUEST";
const char* WIFI_PASSWORD = "";

/************ THINGSPEAK ************/
long myChannelNumber = 3275375;
const char* myApiKey = "BMRA4X3BRXD4WEE2";

WiFiClient client;
WebServer server(80);

/************ GLOBAL STATUS ************/
bool SPRINKLER_STATUS = false;

/************ HTTP HANDLER ************/
void handleSprinkler()
{
  if (server.hasArg("state"))
  {
    String state = server.arg("state");

    if (state == "on")
    {
      SPRINKLER_STATUS = true;
      digitalWrite(SPRINKLER_CONTROL_PIN, HIGH);
      server.send(200, "text/plain", "Sprinkler ON");
    }
    else if (state == "off")
    {
      SPRINKLER_STATUS = false;
      digitalWrite(SPRINKLER_CONTROL_PIN, LOW);
      server.send(200, "text/plain", "Sprinkler OFF");
    }
  }
  else
  {
    server.send(400, "text/plain", "Missing state parameter");
  }
}

/************ SETUP ************/
void setup()
{
  Serial.begin(115200);

  pinMode(SPRINKLER_CONTROL_PIN, OUTPUT);
  dht.begin();

  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_NAME, WIFI_PASSWORD);

  Serial.print("Connecting");

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

  Serial.println("\nWiFi Connected");
  Serial.print("ESP32 IP: ");
  Serial.println(WiFi.localIP());

  // Web server route
  server.on("/sprinkler", handleSprinkler);
  server.begin();

  ThingSpeak.begin(client);
}

/************ LOOP ************/
void loop()
{
  server.handleClient();   // Listen for Raspberry Pi commands

  /******** SENSOR READ ********/
  int sensorValue = analogRead(SOIL_MOISTURE_PIN);
  int soilMoisture =
      constrain(map(sensorValue, 4095, 0, 0, 100), 0, 100);

  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  if (isnan(temperature) || isnan(humidity))
  {
    Serial.println("DHT Read Failed");
    return;
  }

  /******** SERIAL OUTPUT ********/
  Serial.println("------ DATA ------");
  Serial.print("Soil: "); Serial.println(soilMoisture);
  Serial.print("Temp: "); Serial.println(temperature);
  Serial.print("Humidity: "); Serial.println(humidity);
  Serial.print("Sprinkler: ");
  Serial.println(SPRINKLER_STATUS ? "ON" : "OFF");

  /******** THINGSPEAK ********/
  ThingSpeak.setField(1, soilMoisture);
  ThingSpeak.setField(2, temperature);
  ThingSpeak.setField(3, humidity);
  // ThingSpeak.setField(4, SPRINKLER_STATUS);

  ThingSpeak.writeFields(myChannelNumber, myApiKey);

  delay(15000);
} // Thingspeak allows for an update every 15 seconds