#include <Wire.h>
#include <Keypad.h>
#include <Servo.h>
#include <SoftwareSerial.h>
#include <LiquidCrystal_I2C.h>
#include "HX711.h"

bool ALLOW_SENSORS = false;

const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {9, 8, 7, 6};
byte colPins[KEYPAD_COLS] = {5, 4, 3, 2};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
    {'1', '2', '3', '+'},
    {'4', '5', '6', '-'},
    {'7', '8', '9', '*'},
    {'.', '0', '=', '/'}};

HX711 scale;

#define LOADCELL_DOUT_PIN 11
#define LOADCELL_SCK_PIN 10
int CALIB_FACTOR = 0;
bool initMsgShown = false;

#define RE 8
#define DE 7
#define SOIL_MOISTURE_SENSOR_PIN A0

const byte nitro[] = {0x01, 0x03, 0x00, 0x1e, 0x00, 0x01, 0xe4, 0x0c};
const byte phos[] = {0x01, 0x03, 0x00, 0x1f, 0x00, 0x01, 0xb5, 0xcc};
const byte pota[] = {0x01, 0x03, 0x00, 0x20, 0x00, 0x01, 0x85, 0xc0};

byte values[11];

SoftwareSerial mod(2, 3);

LiquidCrystal_I2C lcd(0x27, 16, 4);
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

String authCode;

void clearScreen()
{
    lcd.clear();
}

void showMsg(String msg, int line = 0)
{
    lcd.setCursor(1, line);
    lcd.print(msg);
}

void updateCursor()
{
    if (millis() / 250 % 2 == 0)
    {
        lcd.cursor();
    }
    else
    {
        lcd.noCursor();
    }
}

void checkAuthCode(char key)
{
    if (ALLOW_SENSORS)
        return;

    if (key == '=')
    {
        if (authCode.length() > 4 || authCode.length() <= 0)
        {
            showMsg("Invalid Auth Code, Retry");
            authCode = "";
        }
        else
        {
            if (authCode == "0008")
            {
                showMsg("Auth Success!!");
                ALLOW_SENSORS = true;
                clearScreen();
                showMsg("Loading Sensor Data...");
            }
            else if (authCode == "0000")
            {
                runCalibration();
            }
            else
            {
                showMsg("Wrong Code, Retry");
                authCode = "";
            }
        }
    }
    else
    {
        lcd.print(key);
        authCode += key;
    }
}

void setup()
{
    Serial.begin(9600);
    lcd.begin();
    lcd.backlight();
    lcd.cursor();

    lcd.setCursor(1, 0);
    authCode = "";

    mod.begin(9600);
    pinMode(RE, OUTPUT);
    pinMode(DE, OUTPUT);

    scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
    scale.set_scale(CALIB_FACTOR);
    scale.tare();
}

void loop()
{
    if (!ALLOW_SENSORS)
    {
        if (!initMsgShown)
        {
            showMsg("Enter Auth Code");
            initMsgShown = true;
        }
        char key = keypad.getKey();
        if (key)
        {
            checkAuthCode(key);
        }
    }
    else
    {
        static unsigned long previousUpdateTime = 0;
        const unsigned long updateInterval = 2000; // Update LCD every 2 seconds

        if (millis() - previousUpdateTime >= updateInterval)
        {
            readAndUpdateSensors();
            previousUpdateTime = millis();
        }
    }
}

byte nitrogen()
{
    digitalWrite(DE, HIGH);
    digitalWrite(RE, HIGH);
    delay(10);
    if (mod.write(nitro, sizeof(nitro)) == 8)
    {
        digitalWrite(DE, LOW);
        digitalWrite(RE, LOW);
        for (byte i = 0; i < 7; i++)
        {
            values[i] = mod.read();
        }
    }
    return values[4];
}

byte phosphorous()
{
    digitalWrite(DE, HIGH);
    digitalWrite(RE, HIGH);
    delay(10);
    if (mod.write(phos, sizeof(phos)) == 8)
    {
        digitalWrite(DE, LOW);
        digitalWrite(RE, LOW);
        for (byte i = 0; i < 7; i++)
        {
            values[i] = mod.read();
        }
    }
    return values[4];
}

byte potassium()
{
    digitalWrite(DE, HIGH);
    digitalWrite(RE, HIGH);
    delay(10);
    if (mod.write(pota, sizeof(pota)) == 8)
    {
        digitalWrite(DE, LOW);
        digitalWrite(RE, LOW);
        for (byte i = 0; i < 7; i++)
        {
            values[i] = mod.read();
        }
    }
    return values[4];
}

String soilNPKSensors()
{
    byte val1, val2, val3;
    val1 = nitrogen();
    delay(250);
    val2 = phosphorous();
    delay(250);
    val3 = potassium();
    delay(250);

    String msg = "N: " + String(val1) + "mg/kg     P: " + String(val2) + "mg/kg      K: " + String(val3) + "mg/kg";
    return msg;
}

String soilMoisture()
{
    int sensorValue = analogRead(SOIL_MOISTURE_SENSOR_PIN);
    String s = String(sensorValue);
    return "Soil Moisture: " + s;
}

String phSensor()
{
    String phData;
    for (int i = 1; i <= 10; i++)
    {
        String phdata = Serial.readStringUntil(':');
        if (phdata != "")
        {
            String ph = Serial.readStringUntil('$');
            float phValue = ph.toFloat();
            phData = String(phValue);
        }
    }
    return "ph: " + phData;
}

String loadCell()
{
    float weight = scale.get_units();
    return "Load: " + String(weight, 1) + "kg";
}

void runCalibration()
{
    showMsg("Load cell calibrate");
    clearScreen();
    showMsg("Use + / - ");
    showMsg("To calibrate ", 1);
    showMsg("Press = to finish", 2);
    clearScreen();

    while (1)
    {
        char temp = keypad.getKey();
        if (temp == '=')
        {
            return;
        }
        else if (temp == '+' || temp == 'a')
        {
            CALIB_FACTOR += 10;
        }
        else if (temp == '-' || temp == 'z')
        {
            CALIB_FACTOR -= 10;
        }
    }
}

void readAndUpdateSensors()
{
    // clearScreen();
    String lines[] = {
        loadCell(),
        soilNPKSensors(),
        soilMoisture(),
        phSensor()
          };

    for (int i = 0; i < 4; i++)
    {
        clearScreen();
        showMsg(lines[i]);
        delay(2000);
    }
}