// Loki / Chaff — BLE Countermeasure (Phase 1)
// Broadcasts fake BLE device advertisements with randomized MACs
// to confuse passive BLE surveillance scanners.
//
// Hardware: ESP32-C3 Super Mini
// Framework: Arduino + NimBLE 1.4.x (ESP-IDF 4.4.x required for C3 BLE)

#include <Arduino.h>
#include <NimBLEDevice.h>
// ── Blue status LED on GPIO8 ──
#define LED_PIN 8

// ── Device profiles ──

struct DeviceProfile {
    const char* name;
    uint16_t appearance;
    uint8_t mfgId[2];     // Company ID (little-endian)
    uint8_t mfgData[4];
    uint8_t mfgDataLen;
};

static const DeviceProfile PROFILES[] = {
    {"Galaxy S24",        0x0040, {0x75, 0x00}, {0x42, 0x04, 0x01, 0x80}, 4},
    {"iPhone",            0x0040, {0x4C, 0x00}, {0x02, 0x15, 0x06, 0x01}, 4},
    {"Pixel 9",           0x0040, {0xE0, 0x00}, {0x01, 0x03, 0x00, 0x22}, 4},
    {"OnePlus 12",        0x0040, {0x75, 0x00}, {0x42, 0x04, 0x02, 0x10}, 4},
    {"iPad",              0x0080, {0x4C, 0x00}, {0x02, 0x15, 0x05, 0x03}, 4},
    {"Galaxy Watch6",     0x00C0, {0x75, 0x00}, {0x42, 0x04, 0x03, 0x60}, 4},
    {"Apple Watch",       0x00C0, {0x4C, 0x00}, {0x02, 0x15, 0x0C, 0x01}, 4},
    {"Mi Band 8",         0x02C0, {0x10, 0x03}, {0x01, 0x02, 0x08, 0x00}, 4},
    {"Fitbit Charge 6",   0x00C0, {0xE0, 0x00}, {0x01, 0x01, 0x06, 0x04}, 4},
    {"AirPods Pro",       0x0941, {0x4C, 0x00}, {0x07, 0x19, 0x01, 0x0E}, 4},
    {"Galaxy Buds3",      0x0941, {0x75, 0x00}, {0x42, 0x04, 0x05, 0x21}, 4},
    {"Surface Laptop",    0x0080, {0x06, 0x00}, {0x01, 0x09, 0x02, 0x00}, 4},
    {"Nothing Phone (2)", 0x0040, {0x75, 0x00}, {0x42, 0x04, 0x01, 0x44}, 4},
    {"Bose QC Ultra",     0x0941, {0x0F, 0x00}, {0x02, 0x01, 0x04, 0x08}, 4},
    {"JBL Flip 6",        0x0941, {0x0F, 0x00}, {0x02, 0x01, 0x06, 0x12}, 4},
    {"Sony WH-1000XM5",   0x0941, {0x0F, 0x00}, {0x02, 0x01, 0x05, 0x20}, 4},
};

static const int NUM_PROFILES = sizeof(PROFILES) / sizeof(PROFILES[0]);

static const uint32_t ADV_DURATION_MS = 2000;
static const uint32_t ADV_GAP_MS      = 100;

static int currentProfile = 0;
static NimBLEAdvertising* pAdvertising = nullptr;

static void generateRandomMAC(uint8_t* mac) {
    uint32_t r1 = esp_random();
    uint32_t r2 = esp_random();
    mac[0] = (r1 & 0xFF) | 0xC0;  // Random static address bits
    mac[1] = (r1 >> 8) & 0xFF;
    mac[2] = (r1 >> 16) & 0xFF;
    mac[3] = r2 & 0xFF;
    mac[4] = (r2 >> 8) & 0xFF;
    mac[5] = (r2 >> 16) & 0xFF;
}

static void advertiseProfile(int idx) {
    const DeviceProfile& p = PROFILES[idx];

    pAdvertising->stop();

    // Set new random MAC
    uint8_t mac[6];
    generateRandomMAC(mac);
    ble_hs_id_set_rnd(mac);

    // Build advertisement data
    NimBLEAdvertisementData advData;
    advData.setFlags(BLE_HS_ADV_F_DISC_GEN | BLE_HS_ADV_F_BREDR_UNSUP);
    advData.setName(p.name);
    advData.setAppearance(p.appearance);

    // Manufacturer-specific data
    std::string mfg;
    mfg += (char)p.mfgId[0];
    mfg += (char)p.mfgId[1];
    for (int i = 0; i < p.mfgDataLen; i++) {
        mfg += (char)p.mfgData[i];
    }
    advData.setManufacturerData(mfg);

    pAdvertising->setAdvertisementData(advData);
    pAdvertising->setAdvertisementType(BLE_GAP_CONN_MODE_NON);
    pAdvertising->start();

    Serial.printf("[%4lus] %-20s  MAC %02X:%02X:%02X:%02X:%02X:%02X\n",
                  millis() / 1000, p.name,
                  mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}

void setup() {
    Serial.begin(115200);
    delay(500);

    Serial.println();
    Serial.println("=============================");
    Serial.println("  LOKI — BLE Countermeasure");
    Serial.println("  Phase 1: Identity Cycling");
    Serial.printf("  Profiles: %d devices\n", NUM_PROFILES);
    Serial.println("=============================");
    Serial.println();

    // Blue LED — Loki is active (active LOW on C3 Super Mini)
    pinMode(LED_PIN, OUTPUT);
    digitalWrite(LED_PIN, LOW);

    NimBLEDevice::init("");
    NimBLEDevice::setOwnAddrType(BLE_OWN_ADDR_RANDOM);

    pAdvertising = NimBLEDevice::getAdvertising();

    Serial.println("Broadcasting...\n");
}

void loop() {
    advertiseProfile(currentProfile);
    delay(ADV_DURATION_MS);
    pAdvertising->stop();
    delay(ADV_GAP_MS);
    currentProfile = (currentProfile + 1) % NUM_PROFILES;
}