#include <DHT.h>

// ================= PIN DEFINITIONS =================

#define SOIL_PIN 34
#define RAIN_PIN 32
#define LDR_PIN 35
#define DHT_PIN 4
#define DHT_TYPE DHT22
#define PIR_PIN 27
#define TRIG_PIN 5
#define ECHO_PIN 18
#define BUZZER_PIN 25
#define PUMP_LED_PIN 26

// ================= DHT22 =================

DHT dht(DHT_PIN, DHT_TYPE);

// ================= SETUP =================

void setup() {

  Serial.begin(115200);

  dht.begin();

  pinMode(PIR_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(PUMP_LED_PIN, OUTPUT);

  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(PUMP_LED_PIN, LOW);

  Serial.println();
  Serial.println("================================");
  Serial.println("     SMART AGRICULTURE SYSTEM");
  Serial.println("================================");
}

// ================= ULTRASONIC =================

float getDistance() {

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000);

  if (duration == 0) {
    return -1;
  }

  return duration * 0.0343 / 2;
}

// ================= IRRIGATION SCHEDULE =================

void irrigationSchedule(float temperature,
                        int soilMoisture,
                        int rainLevel) {

  Serial.println();
  Serial.println("---------- IRRIGATION SCHEDULE ----------");

  if (rainLevel >= 50) {

    Serial.println("IRRIGATION      : POSTPONED");
    Serial.println("RECOMMENDED TIME: AFTER RAIN");
    Serial.println("REASON          : Rain detected");
  }

  else if (soilMoisture < 40 && temperature > 35) {

    Serial.println("IRRIGATION      : REQUIRED");
    Serial.println("RECOMMENDED TIME: EARLY MORNING / EVENING");
    Serial.println("REASON          : Soil is dry and temperature is high");
  }

  else if (soilMoisture < 40) {

    Serial.println("IRRIGATION      : REQUIRED");
    Serial.println("RECOMMENDED TIME: MORNING");
    Serial.println("REASON          : Soil moisture is low");
  }

  else {

    Serial.println("IRRIGATION      : NOT REQUIRED");
    Serial.println("RECOMMENDED TIME: NOT REQUIRED");
    Serial.println("REASON          : Soil moisture is sufficient");
  }

  Serial.println("-----------------------------------------");
}

// ================= CROP RECOMMENDATION =================

void cropRecommendation(float temperature,
                        float humidity,
                        int soilMoisture,
                        int rainLevel) {

  Serial.println();
  Serial.println("---------- CROP RECOMMENDATION ----------");

  if (rainLevel < 30 &&
      soilMoisture < 40 &&
      temperature > 30) {

    Serial.println("FIELD CONDITION : HOT & DRY");
    Serial.println("RECOMMENDED CROP: MAIZE / GROUNDNUT");
  }

  else if (rainLevel >= 60 &&
           soilMoisture >= 60 &&
           temperature >= 20 &&
           temperature <= 35) {

    Serial.println("FIELD CONDITION : WET");
    Serial.println("RECOMMENDED CROP: RICE");
  }

  else if (temperature >= 20 &&
           temperature <= 30 &&
           soilMoisture >= 40 &&
           soilMoisture <= 70) {

    Serial.println("FIELD CONDITION : MODERATE");
    Serial.println("RECOMMENDED CROP: VEGETABLES / PULSES");
  }

  else {

    Serial.println("FIELD CONDITION : VARIABLE");
    Serial.println("RECOMMENDED CROP: CHECK LOCAL CONDITIONS");
  }

  Serial.println("-----------------------------------------");
}

// ================= PEST / DISEASE RISK =================

void pestDiseaseRisk(float temperature,
                     float humidity,
                     int soilMoisture,
                     int rainLevel) {

  Serial.println();
  Serial.println("---------- PEST / DISEASE RISK ----------");

  // High humidity + wet conditions
  if (humidity >= 80 &&
      soilMoisture >= 70 &&
      rainLevel >= 60) {

    Serial.println("RISK LEVEL : HIGH");
    Serial.println("RISK TYPE  : FUNGAL DISEASE RISK");
    Serial.println("ACTION     : INSPECT CROPS AND IMPROVE AIR CIRCULATION");
  }

  // Moderate humidity + wet field
  else if (humidity >= 65 &&
           soilMoisture >= 60) {

    Serial.println("RISK LEVEL : MEDIUM");
    Serial.println("RISK TYPE  : PEST / DISEASE RISK");
    Serial.println("ACTION     : INCREASE CROP MONITORING");
  }

  // Hot and dry condition
  else if (temperature > 35 &&
           humidity < 40 &&
           soilMoisture < 40) {

    Serial.println("RISK LEVEL : MEDIUM");
    Serial.println("RISK TYPE  : HEAT / PEST STRESS");
    Serial.println("ACTION     : PROVIDE IRRIGATION AND MONITOR CROPS");
  }

  else {

    Serial.println("RISK LEVEL : LOW");
    Serial.println("RISK TYPE  : NO SIGNIFICANT RISK");
    Serial.println("ACTION     : NORMAL CROP MONITORING");
  }

  Serial.println("-----------------------------------------");
}

// ================= MAIN LOOP =================

void loop() {

  // ---------- DHT22 ----------

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

  // ---------- SOIL MOISTURE ----------

  int soilRaw = analogRead(SOIL_PIN);

  int soilMoisture = map(
    soilRaw,
    4095,
    0,
    0,
    100
  );

  soilMoisture = constrain(
    soilMoisture,
    0,
    100
  );

  // ---------- RAIN SENSOR ----------

  int rainRaw = analogRead(RAIN_PIN);

  int rainLevel = map(
    rainRaw,
    0,
    4095,
    100,
    0
  );

  rainLevel = constrain(
    rainLevel,
    0,
    100
  );

  // ---------- LDR ----------

  int lightRaw = analogRead(LDR_PIN);

  int lightLevel = map(
    lightRaw,
    0,
    4095,
    0,
    100
  );

  lightLevel = constrain(
    lightLevel,
    0,
    100
  );

  // ---------- PIR ----------

  int motion = digitalRead(PIR_PIN);

  // ---------- ULTRASONIC ----------

  float distance = getDistance();

  // =================================================
  // FIELD DATA
  // =================================================

  Serial.println();
  Serial.println("---------- FIELD DATA ----------");

  Serial.print("Temperature   : ");

  if (isnan(temperature)) {
    Serial.println("Sensor Error");
  }
  else {
    Serial.print(temperature);
    Serial.println(" C");
  }

  Serial.print("Humidity      : ");

  if (isnan(humidity)) {
    Serial.println("Sensor Error");
  }
  else {
    Serial.print(humidity);
    Serial.println(" %");
  }

  Serial.print("Soil Moisture : ");
  Serial.print(soilMoisture);
  Serial.println(" %");

  Serial.print("Rain Level    : ");
  Serial.print(rainLevel);
  Serial.println(" %");

  Serial.print("Light Level   : ");
  Serial.print(lightLevel);
  Serial.println(" %");

  if (distance > 0) {

    Serial.print("Distance      : ");
    Serial.print(distance);
    Serial.println(" cm");
  }

  // =================================================
  // IRRIGATION DECISION
  // =================================================

  if (soilMoisture < 40 && rainLevel < 50) {

    digitalWrite(PUMP_LED_PIN, HIGH);

    Serial.println();
    Serial.println("SOIL STATUS   : DRY");
    Serial.println("RAIN STATUS   : NO SIGNIFICANT RAIN");
    Serial.println("IRRIGATION    : REQUIRED");
    Serial.println("PUMP          : ON");
    Serial.println("PUMP LED      : ON");
  }

  else {

    digitalWrite(PUMP_LED_PIN, LOW);

    Serial.println();
    Serial.println("IRRIGATION    : NOT REQUIRED");
    Serial.println("PUMP          : OFF");
    Serial.println("PUMP LED      : OFF");
  }

  // =================================================
  // ANIMAL / INTRUSION DETECTION
  // =================================================

  if (motion == HIGH) {

    tone(BUZZER_PIN, 2000);

    Serial.println();
    Serial.println("!!! INTRUSION ALERT !!!");
    Serial.println("MOVEMENT      : DETECTED");
    Serial.println("BUZZER        : ON");
  }

  else {

    noTone(BUZZER_PIN);

    Serial.println();
    Serial.println("MOVEMENT      : NOT DETECTED");
    Serial.println("BUZZER        : OFF");
  }

  // =================================================
  // ENVIRONMENTAL ALERTS
  // =================================================

  if (!isnan(temperature) && temperature > 35) {

    Serial.println("ALERT         : HIGH TEMPERATURE");
  }

  if (!isnan(humidity) && humidity < 40) {

    Serial.println("ALERT         : LOW HUMIDITY");
  }

  // =================================================
  // IRRIGATION RECOMMENDATION
  // =================================================

  if (soilMoisture < 40 && rainLevel < 50) {

    Serial.println();
    Serial.println("RECOMMENDATION:");
    Serial.println("Irrigation should be provided.");
  }

  else if (rainLevel >= 50) {

    Serial.println();
    Serial.println("RECOMMENDATION:");
    Serial.println("Rain detected. Postpone irrigation.");
  }

  else {

    Serial.println();
    Serial.println("RECOMMENDATION:");
    Serial.println("Soil moisture is sufficient.");
  }

  // =================================================
  // IRRIGATION SCHEDULE
  // =================================================

  if (!isnan(temperature)) {

    irrigationSchedule(
      temperature,
      soilMoisture,
      rainLevel
    );
  }

  // =================================================
  // CROP RECOMMENDATION
  // =================================================

  if (!isnan(temperature) && !isnan(humidity)) {

    cropRecommendation(
      temperature,
      humidity,
      soilMoisture,
      rainLevel
    );
  }

  // =================================================
  // PEST / DISEASE RISK
  // =================================================

  if (!isnan(temperature) && !isnan(humidity)) {

    pestDiseaseRisk(
      temperature,
      humidity,
      soilMoisture,
      rainLevel
    );
  }

  Serial.println();
  Serial.println("================================");

  // Wait 10 seconds before next reading

  delay(10000);
}