#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include "LittleFS.h"
#include "connect.h" 

// MQTT Topic
const char* topic = "water/quality";

// Temperature Sensor (DS18B20)
#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// Analog Pins (Wired to Potentiometers in Wokwi)
#define PH_PIN 34
#define TURBIDITY_PIN 35
#define TDS_PIN 32

// Using standard WiFiClient for port 1883 browser simulation
WiFiClient espClient;
PubSubClient client(espClient);

// Timing
unsigned long lastMsg = 0;
const long interval = 10000; // 5 seconds

// ==========================================
// SETUP WIFI
// ==========================================
void setup_wifi() {
  delay(10);
  Serial.println("Connecting to WiFi...");
  WiFi.begin(esp_SSID, esp_PASS);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

// ==========================================
// RECONNECT MQTT
// ==========================================
void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting MQTT...");
    
    // Randomized Client ID to prevent MQTT Explorer collisions
    String clientId = "Aqua";
    clientId += String(random(0, 100));

    if (client.connect(clientId.c_str())) {
      Serial.println("MQTT Connected");
      replayBufferedData();
    } else {
      Serial.print("Failed MQTT: ");
      Serial.println(client.state());
      delay(20000);
    }
  }
}

// ==========================================
// SAVE TO LITTLEFS
// ==========================================
void saveToBuffer(String payload) {
  File file = LittleFS.open("/buffer.txt", FILE_APPEND);
  if (!file) {
    Serial.println("❌ Failed to open buffer file");
    return;
  }
  file.println(payload);
  file.close();
  Serial.println("📁 Data buffered locally");
}

// ==========================================
// REPLAY BUFFERED DATA
// ==========================================
void replayBufferedData() {
  File file = LittleFS.open("/buffer.txt", FILE_READ);
  if (!file || file.size() == 0) {
    Serial.println("✅ No buffered data to replay");
    return;
  }

  Serial.println("🔄 Replaying buffered data...");
  while (file.available()) {
    String line = file.readStringUntil('\n');
    line.trim();

    if (line.length() > 0) {
      bool success = client.publish(topic, line.c_str());
      if (success) {
        Serial.println("✅ Replayed: " + line);
      } else {
        Serial.println("❌ Replay failed");
        break;
      }
      delay(300);
    }
  }
  file.close();
  LittleFS.remove("/buffer.txt");
  Serial.println("🧹 Buffer cleared");
}

// ==========================================
// SIMPLIFIED SENSOR FUNCTIONS (SILENT)
// ==========================================
float readPH() {
  int raw = analogRead(PH_PIN);
  return (raw / 4095.0) * 14.0;
}

float readTurbidity() {
  int raw = analogRead(TURBIDITY_PIN);
  return (raw / 4095.0) * 29.0 + 1.0;
}

float readTDS(float temperature) {
  int raw = analogRead(TDS_PIN);
  return (raw / 4095.0) * 1000.0;
}

// ==========================================
// SETUP
// ==========================================
void setup() {
  Serial.begin(115200);

  if (!LittleFS.begin(true)) {
    Serial.println("⚠ LittleFS Mount Failed - Proceeding without offline buffer");
  } else {
    Serial.println("✅ LittleFS Ready");
  }

  setup_wifi();

  client.setServer(mqtt_SERVER, 1883); 
  client.setBufferSize(1024);

  sensors.begin();
}

// ==========================================
// MAIN LOOP
// ==========================================
void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("⚠ WiFi Lost");
    setup_wifi();
  }

  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();

  unsigned long now = millis();
  if (now - lastMsg > interval) {
    lastMsg = now;

    // Read Sensors silently
    sensors.requestTemperatures();
    float temperature = sensors.getTempCByIndex(0);
    float ph = readPH();
    float turbidity = readTurbidity();
    float tds = readTDS(temperature);

    // Create JSON Payload
    String payload = "{";
    payload += "\"ph\":" + String(ph, 2) + ",";
    payload += "\"temperature\":" + String(temperature, 2) + ",";
    payload += "\"tds\":" + String(tds, 2) + ",";
    payload += "\"turbidity\":" + String(turbidity, 2);
    payload += "}";

    // Publish and Print Result
    bool success = client.publish(topic, payload.c_str());

    if (!success) {
      Serial.println("❌ MQTT Publish Failed");
      saveToBuffer(payload);
    } else {
      Serial.println("✅ MQTT Published: " + payload);
    }
  }
}