#include <WiFi.h>
#include <HTTPClient.h>

// ---------------- PIN DEFINITIONS ----------------
#define TRIG_MAIN 5
#define ECHO_MAIN 18
#define TRIG_SUB 27
#define ECHO_SUB 14
#define TDS_PIN 32
#define POT_PRESSURE1 34
#define POT_PRESSURE2 33
#define POT_FLOW1 35
#define POT_FLOW2 36
#define LED1 25
#define LED2 26

// ---------------- WIFI + FIREBASE ----------------
const char* ssid = "Wokwi-GUEST";    // WiFi SSID
const char* password = "";           // WiFi Password

// Replace with your Firebase Realtime Database URL
// Example: "https://your-project-id-default-rtdb.firebaseio.com"
String firebaseHost = "https://hydronet-monitor-default-rtdb.firebaseio.com";
String firebaseAuth = "KwfkB1eVB2szYTYMRtvPbbrgUZo5fahyDMXUEQ3";  // Optional if not public

// ---------------- VARIABLES ----------------
float distanceMain, distanceSub;
float waterLevelMain, waterLevelSub;
float tdsValue, pressure1, pressure2, flow1, flow2;
const float tankHeight = 400.0;

void setup() {
  Serial.begin(115200);

  // --- Pin Modes ---
  pinMode(TRIG_MAIN, OUTPUT);
  pinMode(ECHO_MAIN, INPUT);
  pinMode(TRIG_SUB, OUTPUT);
  pinMode(ECHO_SUB, INPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);

  // --- WiFi Connection ---
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\n✅ WiFi Connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// Function to measure distance using Ultrasonic Sensor
float getDistance(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH, 30000); // timeout 30ms
  float distance = duration * 0.034 / 2;         // cm
  return distance;
}

void loop() {
  // --- Measure Water Levels ---
  distanceMain = getDistance(TRIG_MAIN, ECHO_MAIN);
  distanceSub  = getDistance(TRIG_SUB, ECHO_SUB);
  waterLevelMain = tankHeight - distanceMain;
  waterLevelSub  = tankHeight - distanceSub;
  if (waterLevelMain < 0) waterLevelMain = 0;
  if (waterLevelSub < 0)  waterLevelSub  = 0;

  // --- Read TDS ---
  int tdsRaw = analogRead(TDS_PIN);
  tdsValue = (tdsRaw / 4095.0) * 1000;  // ppm scale (example calibration)

  // --- Read Pressure & Flow ---
  pressure1 = analogRead(POT_PRESSURE1) / 40.95; // 0–100
  pressure2 = analogRead(POT_PRESSURE2) / 40.95;
  flow1 = analogRead(POT_FLOW1) / 40.95;         // 0–100
  flow2 = analogRead(POT_FLOW2) / 40.95;

  // --- LED Logic ---
  if (pressure2 > pressure1) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
  } else {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);
  }

  // --- Print to Serial ---
  Serial.println("------ SENSOR DATA ------");
  Serial.printf("Main Tank Level: %.2f cm\n", waterLevelMain);
  Serial.printf("Sub Tank Level : %.2f cm\n", waterLevelSub);
  Serial.printf("TDS Value      : %.2f ppm\n", tdsValue);
  Serial.printf("Pressure1      : %.2f\n", pressure1);
  Serial.printf("Pressure2      : %.2f\n", pressure2);
  Serial.printf("Flow1          : %.2f\n", flow1);
  Serial.printf("Flow2          : %.2f\n", flow2);
  Serial.println("--------------------------");

  // --- Upload to Firebase (Sequential POST) ---
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;

    // Each POST creates a new unique entry under "TankData"
    String url = firebaseHost + "/TankData.json?auth=" + firebaseAuth;
    http.begin(url);
    http.addHeader("Content-Type", "application/json");

    // Add a timestamp field to identify entries
    unsigned long timestamp = millis() / 1000;

    String payload = "{";
    payload += "\"timestamp\": " + String(timestamp) + ",";
    payload += "\"MainTank_Level\": " + String(waterLevelMain) + ",";
    payload += "\"SubTank_Level\": " + String(waterLevelSub) + ",";
    payload += "\"TDS\": " + String(tdsValue) + ",";
    payload += "\"Pressure1\": " + String(pressure1) + ",";
    payload += "\"Pressure2\": " + String(pressure2) + ",";
    payload += "\"Flow1\": " + String(flow1) + ",";
    payload += "\"Flow2\": " + String(flow2);
    payload += "}";

    int httpCode = http.POST(payload);

    if (httpCode > 0) {
      Serial.printf("✅ Firebase POST Response Code: %d\n", httpCode);
      Serial.println("Data pushed successfully!");
    } else {
      Serial.printf("⚠️ HTTP Error: %s\n", http.errorToString(httpCode).c_str());
    }

    http.end();
  } else {
    Serial.println("❌ WiFi disconnected, skipping upload.");
  }

  delay(3000); // 3 seconds between uploads
}