* Refactor: new AdvertDataHelpers.h

src/helpers/AdvertDataHelpers.h

@@ -0,0 +1,101 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define ADV_TYPE_NONE         0   // unknown
+#define ADV_TYPE_CHAT         1
+#define ADV_TYPE_REPEATER     2
+#define ADV_TYPE_ROOM         3   // New kid on the block!
+//FUTURE: 4..15
+
+#define ADV_LATLON_MASK       0x10
+#define ADV_BATTERY_MASK      0x20
+#define ADV_TEMPERATURE_MASK  0x40
+#define ADV_NAME_MASK         0x80
+
+class AdvertDataBuilder {
+  uint8_t _type;
+  const char* _name;
+  int32_t _lat, _lon;
+public:
+  AdvertDataBuilder(uint8_t adv_type) : _type(adv_type), _name(NULL), _lat(0), _lon(0) { }
+  AdvertDataBuilder(uint8_t adv_type, const char* name) : _type(adv_type), _name(name), _lat(0), _lon(0)  { }
+  AdvertDataBuilder(uint8_t adv_type, const char* name, double lat, double lon) : 
+      _type(adv_type), _name(name), _lat(lat * 1E6), _lon(lon * 1E6)  { }
+
+  /**
+   * \brief  encode the given advertisement data.
+   * \param app_data  dest array, must be MAX_ADVERT_DATA_SIZE
+   * \returns  the encoded length in bytes
+   */
+  uint8_t encodeTo(uint8_t app_data[]) {
+    app_data[0] = _type;
+    int i = 1;
+    if (!(_lat == 0 && _lon == 0)) {
+      app_data[0] |= ADV_LATLON_MASK;
+      memcpy(&app_data[i], &_lat, 4); i += 4;
+      memcpy(&app_data[i], &_lon, 4); i += 4;
+    }
+    // TODO:  BATTERY encoding
+    // TODO:  TEMPERATURE encoding
+    if (_name && *_name != 0) { 
+      app_data[0] |= ADV_NAME_MASK;
+      const char* sp = _name;
+      while (*sp && i < MAX_ADVERT_DATA_SIZE) {
+        app_data[i++] = *sp++;
+      }
+    }
+    return i;
+  }
+};
+
+class AdvertDataParser {
+  uint8_t _flags;
+  bool _valid;
+  char _name[MAX_ADVERT_DATA_SIZE];
+  int32_t _lat, _lon;
+public:
+  AdvertDataParser(const uint8_t app_data[], uint8_t app_data_len) {
+    _name[0] = 0;
+    _lat = _lon = 0;
+    _flags = app_data[0];
+    _valid = false;
+
+    int i = 1;
+    if (_flags & ADV_LATLON_MASK) {
+      memcpy(&_lat, &app_data[i], 4); i += 4;
+      memcpy(&_lon, &app_data[i], 4); i += 4;
+    }
+    if (_flags & ADV_BATTERY_MASK) {
+      /* TODO: somewhere to store battery volts? */ i += 2;
+    }
+    if (_flags & ADV_TEMPERATURE_MASK) {
+      /* TODO: somewhere to store temperature? */ i += 2;
+    }
+
+    if (app_data_len >= i) {
+      int nlen = 0;
+      if (_flags & ADV_NAME_MASK) {
+        nlen = app_data_len - i;  // remainder of app_data
+      }
+      if (nlen > 0) {
+        memcpy(_name, &app_data[i], nlen);
+        _name[nlen] = 0;  // set null terminator
+      }
+      _valid = true;
+    }
+  }
+
+  bool isValid() const { return _valid; }
+  uint8_t getType() const { return _flags & 0x0F; }
+
+  bool hasName() const { _name[0] != 0; }
+  const char* getName() const { return _name; }
+
+  bool hasLatLon() const { return !(_lat == 0 && _lon == 0); }
+  int32_t getIntLat() const { return _lat; }
+  int32_t getIntLon() const { return _lon; }
+  double getLat() const { return ((double)_lat) / 1000000.0; }
+  double getLon() const { return ((double)_lon) / 1000000.0; }
+};