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

// Set the LCD address to 0x27 or your specific address and define the size (20x4 LCD)
LiquidCrystal_I2C lcd(0x27, 20, 4);

const int displayInterval = 3000;  // 3 seconds delay
unsigned long lastDisplayChange = 0;
int currentPage = 0;

String receivedMETAR = "";
bool metarReceived = false;

// Struct to hold parsed METAR data
struct METARData {
  String station;
  String datetime;
  String wind;
  String visibility;
  String clouds;
  String temperature;
  String dewpoint;
  String pressure;
};

// Create a METARData object
METARData metarData;

// Function to simulate METAR parsing and populate the METARData object
void parseMETAR(String metarMessage) {
  // Parse the METAR message (this is a simplified example)
  // In reality, METAR parsing can be more complex based on various formats
  metarData.station = metarMessage.substring(0, 4);  // First 4 chars are the station code
  metarData.datetime = "2024-10-09 12:30";           // Example datetime
  metarData.wind = "Wind: 220/15KT";                 // Example wind info
  metarData.visibility = "Visibility: 10KM";         // Example visibility
  metarData.clouds = "Clouds: SCT030 BKN040";        // Example cloud coverage
  metarData.temperature = "Temp: 22°C";              // Example temperature
  metarData.dewpoint = "Dewpoint: 12°C";             // Example dewpoint
  metarData.pressure = "Pressure: 1012 hPa";         // Example pressure
}

// Function to convert METARData object to JSON
String metarToJSON() {
  // Create a JSON document
  StaticJsonDocument<256> doc;

  // Populate JSON with data from the metarData struct
  doc["station"] = metarData.station;
  doc["datetime"] = metarData.datetime;
  doc["wind"] = metarData.wind;
  doc["visibility"] = metarData.visibility;
  doc["clouds"] = metarData.clouds;
  doc["temperature"] = metarData.temperature;
  doc["dewpoint"] = metarData.dewpoint;
  doc["pressure"] = metarData.pressure;

  // Convert JSON object to string
  String jsonStr;
  serializeJson(doc, jsonStr);

  return jsonStr;
}

// Function to display METAR data on the LCD in pages
void displayMETAR() {
  lcd.clear();

  if (currentPage == 0) {
    lcd.setCursor(0, 0); lcd.print(metarData.station);
    lcd.setCursor(0, 1); lcd.print(metarData.datetime);
    lcd.setCursor(0, 2); lcd.print(metarData.wind);
    lcd.setCursor(0, 3); lcd.print(metarData.visibility);
  } else if (currentPage == 1) {
    lcd.setCursor(0, 0); lcd.print(metarData.clouds);
    lcd.setCursor(0, 1); lcd.print(metarData.temperature);
    lcd.setCursor(0, 2); lcd.print(metarData.dewpoint);
    lcd.setCursor(0, 3); lcd.print(metarData.pressure);
  }
  else {
    metarReceived = false;
    lcd.clear();
    lcd.setCursor(0, 0); lcd.print("Waiting for METAR");
  }

  currentPage = (currentPage + 1) % 3; // Toggle between pages 0, 1 and 2
}

void setup() {
  // Initialize serial and LCD
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();

  // Display startup message
  lcd.setCursor(0, 0); lcd.print("Waiting for METAR");

  // Wait for a METAR message over Serial (for example)
}

void loop() {
  // Check for incoming METAR message
  if (Serial.available()) {
    char incomingChar = Serial.read();
    if (incomingChar == '\n') {
      metarReceived = true;
      parseMETAR(receivedMETAR);
      receivedMETAR = "";  // Reset buffer
    } else {
      receivedMETAR += incomingChar;
    }
  }

  // If METAR received, process and display data
  if (metarReceived) {
    if (millis() - lastDisplayChange > displayInterval) {
      lastDisplayChange = millis();
      displayMETAR(); // Show the data on the LCD
    }

    // Output METAR data as JSON over Serial
    String jsonStr = metarToJSON();
    Serial.println(jsonStr);
  }
  
}