#include <WiFi.h>
#include <PubSubClient.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <Wire.h>
#include <SPI.h>

// --- Wi-Fi & MQTT Configuration ---
// No need to change for Wokwi simulation
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";

// --- Topics ---
// IMPORTANT: Change "yourname" to something unique!
const char* data_topic = "antariksha/yourname/data";
const char* command_topic = "antariksha/yourname/command";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[100];

// --- Hardware Pins and Objects ---
#define TFT_CS    5
#define TFT_RST   4
#define TFT_DC    2
#define MPU_ADDR 0x68
#define LED_PIN   2 // ESP32 built-in LED

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
int16_t AcX, AcY, AcZ, Tmp, GyX, GyY, GyZ;
String lastCommand = "none";

// --- Function Prototypes ---
void setup_wifi();
void callback(char* topic, byte* payload, unsigned int length);
void reconnect();
void updateDisplay(String wifiStatus, String mqttStatus);


void setup() {
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(115200);
  Wire.begin();
  
  tft.begin();
  tft.setRotation(3);
  
  setupMPU();
  setup_wifi();
  
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println(message);
  lastCommand = message; // Store the last command

  if (message == "LED_ON") {
    digitalWrite(LED_PIN, HIGH);
  } else if (message == "LED_OFF") {
    digitalWrite(LED_PIN, LOW);
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      client.subscribe(command_topic);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  long now = millis();
  if (now - lastMsg > 5000) { // Publish every 5 seconds
    lastMsg = now;
    readSensorData();
    float tempC = (Tmp / 340.00) + 36.53;

    // Create JSON payload
    snprintf(msg, 100,
      "{\"AcX\":%d, \"AcY\":%d, \"AcZ\":%d, \"GyX\":%d, \"GyY\":%d, \"GyZ\":%d, \"TempC\":%.2f}",
      AcX, AcY, AcZ, GyX, GyY, GyZ, tempC
    );

    Serial.print("Publish message: ");
    Serial.println(msg);
    client.publish(data_topic, msg);
  }
  
  // Update the display with sensor data and status
  readSensorData();
  String wifiStatus = (WiFi.status() == WL_CONNECTED) ? "OK" : "Connecting...";
  String mqttStatus = client.connected() ? "OK" : "Reconnecting...";
  updateDisplay(wifiStatus, mqttStatus);
  delay(500);
}

void setupMPU() {
  Wire.beginTransmission(MPU_ADDR);
  Wire.write(0x6B);
  Wire.write(0);
  Wire.endTransmission(true);
}

void readSensorData() {
  Wire.beginTransmission(MPU_ADDR);
  Wire.write(0x3B);
  Wire.endTransmission(false);
  Wire.requestFrom(MPU_ADDR, 14, true);
  AcX = Wire.read() << 8 | Wire.read();  
  AcY = Wire.read() << 8 | Wire.read();
  AcZ = Wire.read() << 8 | Wire.read();
  Tmp = Wire.read() << 8 | Wire.read();
  GyX = Wire.read() << 8 | Wire.read();
  GyY = Wire.read() << 8 | Wire.read();
  GyZ = Wire.read() << 8 | Wire.read();
}

void updateDisplay(String wifiStatus, String mqttStatus) {
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextSize(2);
  
  // Display Sensor Data
  tft.setCursor(10, 10);
  tft.setTextColor(ILI9341_GREEN);
  tft.printf("AcX: %d\n", AcX);
  tft.setCursor(10, 40);
  tft.printf("AcY: %d\n", AcY);
  
  // Status Indicators
  tft.setCursor(10, 180);
  tft.setTextColor(ILI9341_WHITE);
  tft.printf("WiFi: %s\n", wifiStatus.c_str());
  tft.setCursor(10, 210);
  tft.printf("MQTT: %s\n", mqttStatus.c_str());
  
  // Last Command Received
  tft.setCursor(170, 180);
  tft.setTextColor(ILI9341_YELLOW);
  tft.printf("Cmd: %s", lastCommand.c_str());
}