#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

#define LED_PIN 23
#define BUZZER_PIN 25
#define SLIDE_POT_PIN 35   // Slide potentiometer → UV-C intensity

// Thresholds for ML prediction
#define GLYPHOSATE_THRESHOLD 5.0
#define UV_THRESHOLD 20

// Simulate sensor readings gradually
float simulate_sensor(float &val, float minVal, float maxVal) {
    val += random(-15,16)/100.0;
    if(val < minVal) val = minVal;
    if(val > maxVal) val = maxVal;
    return val;
}

// Show dashboard (initial interface)
void show_dashboard() {
    display.clearDisplay();
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.setCursor(0,0);
    display.println("Glyphosate Detector");
    display.setCursor(0,12);
    display.println("UV-C LED: 255-280 nm");
    display.setCursor(0,24);
    display.println("Collecting readings...");
    display.display();
}

void setup() {
    Serial.begin(115200);
    pinMode(LED_PIN, OUTPUT);
    pinMode(BUZZER_PIN, OUTPUT);
    pinMode(SLIDE_POT_PIN, INPUT);

    if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)){
        Serial.println("SSD1306 not found");
        while(1) delay(10);
    }

    randomSeed(analogRead(0));
    show_dashboard();
    delay(2000);
}

void loop() {
    const int numReadings = 10;
    float glyReadings[numReadings];
    float uvReadings[numReadings];

    float simulatedGly = random(0,1001)/100.0;   // 0-10 mg/L

    // Take readings
    for(int i=0;i<numReadings;i++){
        float gly = simulate_sensor(simulatedGly,0,10);          // Automatic glyphosate
        float uv = map(analogRead(SLIDE_POT_PIN),0,4095,0,100); // UV-C manually via slide pot

        glyReadings[i] = gly;
        uvReadings[i] = uv;

        // Show **current reading** on OLED
        display.clearDisplay();
        display.setTextSize(1);
        display.setCursor(0,0);
        display.println("Current Reading:");
        display.setCursor(0,16);
        display.print("Glyphosate: "); display.print(gly,2); display.println(" mg/L");
        display.setCursor(0,32);
        display.print("UV-C: "); display.print(uv,0); display.println("%");
        display.display();

        delay(300); // small delay between readings
    }

    // Calculate average
    float avgGly = 0, avgUV = 0;
    for(int i=0;i<numReadings;i++){
        avgGly += glyReadings[i];
        avgUV += uvReadings[i];
    }
    avgGly /= numReadings;
    avgUV /= numReadings;

    // ML prediction
    String mlPrediction = (avgGly >= GLYPHOSATE_THRESHOLD && avgUV >= UV_THRESHOLD) ? "UNSAFE" : "SAFE";

    // Alerts
    digitalWrite(LED_PIN, mlPrediction=="UNSAFE"?HIGH:LOW);
    if(mlPrediction=="UNSAFE") tone(BUZZER_PIN, 1000);
    else noTone(BUZZER_PIN);

    // Show ML prediction on OLED
    display.clearDisplay();
    display.setTextSize(1);
    display.setCursor(0,0);
    display.print("Avg Glyphosate: "); display.print(avgGly,2); display.println(" mg/L");
    display.setCursor(0,16);
    display.print("Avg UV-C: "); display.print(avgUV,0); display.println("%");
    display.setCursor(0,32);
    display.print("ML Prediction: "); display.println(mlPrediction);
    display.setCursor(0,48);
    display.println("Peak Abs: 205 nm");
    display.display();

    // Serial output
    Serial.print("Avg Glyphosate: "); Serial.print(avgGly,2);
    Serial.print(" mg/L | Avg UV-C: "); Serial.print(avgUV,0);
    Serial.print("% | ML Prediction: "); Serial.println(mlPrediction);

    delay(5000);
    show_dashboard();
    delay(2000);
}