wifi_scan_result.h

/*
 Copyright (C) AC SOFTWARE SP. Z O.O.
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/
 
#ifndef SRC_SUPLA_NETWORK_WIFI_SCAN_RESULT_H_
#define SRC_SUPLA_NETWORK_WIFI_SCAN_RESULT_H_
 
#include <stdint.h>
 
namespace Supla {
 
constexpr uint8_t WifiScanMaxResults = 16;
constexpr uint8_t WifiScanSsidMaxSize = 33;
constexpr uint32_t WifiScanDefaultMaxAgeMs = 5 * 60 * 1000;
 
struct WifiScanResult {
  char ssid[WifiScanSsidMaxSize] = {};
  int32_t rssi = 0;
  int32_t channel = 0;
};
 
enum class WifiScanLookupStatus : uint8_t {
  NotAvailable,
  Found,
  NotFound,
  Stale,
};
 
class WifiScanResultCache {
 public:
  static WifiScanResultCache *Instance();
 
  void clear();
  void beginUpdate();
  void addOrUpdate(const char *ssid, int32_t rssi, int32_t channel);
  void finishUpdate(uint32_t timestampMs);
 
  WifiScanLookupStatus lookup(const char *ssid,
                              WifiScanResult *result,
                              uint32_t nowMs,
                              uint32_t maxAgeMs =
                                  WifiScanDefaultMaxAgeMs) const;
 
  uint8_t getCount() const;
  uint32_t getTimestampMs() const;
  bool hasScan() const;
  bool getResult(uint8_t index, WifiScanResult *result) const;
 
 private:
  void sortByRssi();
  int find(const char *ssid) const;
  int findWeakest() const;
 
  WifiScanResult entries[WifiScanMaxResults] = {};
  uint8_t count = 0;
  uint32_t timestampMs = 0;
  bool scanAvailable = false;
};
 
}  // namespace Supla
 
#endif  // SRC_SUPLA_NETWORK_WIFI_SCAN_RESULT_H_