#include <Arduino.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Pin Definitions
#define OUT_PIN 4
#define LEDRED 16
#define LEDGREEN 17

// Threshold Definition
#define CHEMICAL_THRESHOLD 50

// Create an LCD object (I2C address 0x27, 16 characters, 2 lines)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Function to simulate chemical concentration readings
int readChemicalConcentration() {
    return random(50, 101);  // Random value between 0-100 ppm
}

void setup() {
    // Initialize Serial Communication
    Serial.begin(115200);

    // Initialize Pins
    pinMode(OUT_PIN, OUTPUT);
    pinMode(LEDRED, OUTPUT);
    pinMode(LEDGREEN, OUTPUT);

    // Initialize LCD
    lcd.init();
    lcd.backlight();
    lcd.setCursor(0, 0);
    lcd.print("Chemical Sensor");
    lcd.setCursor(0, 1);
    lcd.print("Initializing...");
    delay(2000);

    // Generate random concentration
    randomSeed(analogRead(A0));
    lcd.clear();
    int concentration = readChemicalConcentration();

    // Hazard Detection Logic
    if (concentration > CHEMICAL_THRESHOLD) {
        // Hazardous: Turn on RED LED, show alert
        digitalWrite(OUT_PIN, HIGH);
        digitalWrite(LEDRED, HIGH);
        digitalWrite(LEDGREEN, LOW);
        Serial.print("Hazardous chemical detected! Concentration: ");

        lcd.setCursor(0, 0);
        lcd.print("ALERT: HAZARD");
        lcd.setCursor(0, 1);
        lcd.print("Alert sent to Municipality");
    } else {
        // Safe: Turn on GREEN LED
        digitalWrite(OUT_PIN, LOW);
        digitalWrite(LEDRED, LOW);
        digitalWrite(LEDGREEN, HIGH);
        Serial.print("Safe chemical level. Concentration: ");

        lcd.setCursor(0, 0);
        lcd.print("Status: Safe");
        lcd.setCursor(0, 1);
        lcd.print("Conc: ");
        lcd.print(concentration);
        lcd.print(" ppm");
    }

    Serial.println(concentration);
}

void loop() {
    delay(1000);  // Delay before next operation (can be extended if no new readings)
}