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

// ==========================================
// 1. SETTINGS - DISTRIBUTED UPGRADE
// ==========================================
const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* RUST_SERVER_URL = "http://refried-broadly-landslide.ngrok-free.dev/telemetry";
// 2. FLEET SETTINGS
struct VirtualBattery {
  String id;
  float v_offset;
  float t_offset;
};

VirtualBattery fleet[] = {
  {"BAT_001",  0.0f,   0.0f},
  {"BAT_002", -0.3f,   5.0f},
  {"BAT_003", -0.6f,  15.0f},
  {"BAT_004",  0.0f,  20.0f},
  {"BAT_005",  0.2f,  -5.0f}
};

int fleetSize = 5;
int currentDeviceIndex = 0;

// 3. ML SETTINGS
#define INPUTS 9

// FIX 1: Added [INPUTS] — these are arrays, not scalar floats
float SCALER_MEAN[INPUTS]  = {3.5024, 0.2399, 2.3877, 3.9813, -2.0050, 0.0016, 31.9615, 3.6719, 39.4484};
float SCALER_SCALE[INPUTS] = {0.0560, 0.0164, 0.2197, 0.0242,  0.0094, 0.0004,  0.8638, 0.3667,  1.4285};

static float sigmoid(float x) {
  if (x >= 0) return 1.0f / (1.0f + expf(-x));
  else        return expf(x) / (1.0f + expf(x));
}

static float predict(float *x) {
  // FIX 2: Added [9] — w is an array, not a scalar float
  const float w[9] = {-1.2f, 0.2f, -0.6f, 0.7f, -1.8f, 0.3f, 1.1f, 0.2f, 0.5f};
  float b = -0.15f;
  float s = b;
  for (int i = 0; i < INPUTS; i++) s += w[i] * x[i];
  return sigmoid(s);
}

void setup() {
  Serial.begin(115200);
  Serial.println("SYSTEM READY: Distributed DB Mode");

  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" CONNECTED!");
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {

    // A. GENERATE DATA
    VirtualBattery currentBat = fleet[currentDeviceIndex];
    float base_voltage = random(300, 420) / 100.0;
    float base_temp    = random(2000, 6000) / 100.0;
    float sim_current  = random(-210, -190) / 100.0;

    float sim_voltage = base_voltage + currentBat.v_offset;
    float sim_temp    = base_temp    + currentBat.t_offset;

    // FIX 3: features is now a proper array with [INPUTS]
    // FIX 4: Each element assigned with correct index [0]..[8]
    float features[INPUTS];
    features[0] = sim_voltage;
    features[1] = 0.2399f;
    features[2] = sim_voltage - 0.5f;
    features[3] = sim_voltage + 0.5f;
    features[4] = sim_current;
    features[5] = 0.0016f;
    features[6] = sim_temp;
    features[7] = 3.67f;
    features[8] = sim_temp + 5.0f;

    // Normalize
    for (int i = 0; i < INPUTS; i++) {
      features[i] = (features[i] - SCALER_MEAN[i]) / SCALER_SCALE[i];
    }

    // FIX 5: features array decays to float* automatically — no cast needed
    float prediction_score = predict(features);
    String batteryStatus = (prediction_score > 0.5f) ? "ABNORMAL" : "HEALTHY";

    // B. SEND DATA VIA JSON POST
    WiFiClient client;
    HTTPClient http;

    http.begin(client, RUST_SERVER_URL);
    http.addHeader("Content-Type", "application/json");
    http.addHeader("ngrok-skip-browser-warning", "69420");

    String jsonPayload = "{";
    jsonPayload += "\"id\":\""     + currentBat.id               + "\",";
    jsonPayload += "\"voltage\":"  + String(sim_voltage, 2)      + ",";
    jsonPayload += "\"current\":"  + String(sim_current, 2)      + ",";
    jsonPayload += "\"temp\":"     + String(sim_temp, 2)         + ",";
    jsonPayload += "\"score\":"    + String(prediction_score, 4) + ",";
    jsonPayload += "\"status\":\"" + batteryStatus               + "\"";
    jsonPayload += "}";

    Serial.print("Sending (" + currentBat.id + ") to Rust... ");
    int httpResponseCode = http.POST(jsonPayload);

    if (httpResponseCode > 0) {
      Serial.print("HTTP Success: ");
      Serial.println(httpResponseCode);
    } else {
      Serial.print("HTTP Error: ");
      Serial.println(http.errorToString(httpResponseCode).c_str());
    }

    http.end();
    currentDeviceIndex = (currentDeviceIndex + 1) % fleetSize;

  } else {
    Serial.println("WiFi Lost. Reconnecting...");
    WiFi.begin(ssid, password);
  }

  delay(6000);
}