Refactor bridge implementations to inherit from BridgeBase

src/helpers/bridges/BridgeBase.h

@@ -0,0 +1,84 @@
+#pragma once
+
+#include "helpers/AbstractBridge.h"
+#include "helpers/SimpleMeshTables.h"
+
+#include <RTClib.h>
+
+/**
+ * @brief Base class implementing common bridge functionality
+ *
+ * This class provides common functionality used by different bridge implementations
+ * like packet tracking, checksum calculation, timestamping, and duplicate detection.
+ *
+ * Features:
+ * - Fletcher-16 checksum calculation for data integrity
+ * - Packet duplicate detection using SimpleMeshTables
+ * - Common timestamp formatting for debug logging
+ * - Shared packet management and queuing logic
+ */
+class BridgeBase : public AbstractBridge {
+public:
+  virtual ~BridgeBase() = default;
+
+protected:
+  /** Packet manager for allocating and queuing mesh packets */
+  mesh::PacketManager *_mgr;
+
+  /** RTC clock for timestamping debug messages */
+  mesh::RTCClock *_rtc;
+
+  /** Tracks seen packets to prevent loops in broadcast communications */
+  SimpleMeshTables _seen_packets;
+
+  /**
+   * @brief Constructs a BridgeBase instance
+   *
+   * @param mgr PacketManager for allocating and queuing packets
+   * @param rtc RTCClock for timestamping debug messages
+   */
+  BridgeBase(mesh::PacketManager *mgr, mesh::RTCClock *rtc) : _mgr(mgr), _rtc(rtc) {}
+
+  /**
+   * @brief Gets formatted date/time string for logging
+   *
+   * Format: "HH:MM:SS - DD/MM/YYYY U"
+   *
+   * @return Formatted date/time string
+   */
+  const char *getLogDateTime();
+
+  /**
+   * @brief Calculate Fletcher-16 checksum
+   *
+   * Based on: https://en.wikipedia.org/wiki/Fletcher%27s_checksum
+   * Used to verify data integrity of received packets
+   *
+   * @param data Pointer to data to calculate checksum for
+   * @param len Length of data in bytes
+   * @return Calculated Fletcher-16 checksum
+   */
+  static uint16_t fletcher16(const uint8_t *data, size_t len);
+
+  /**
+   * @brief Validate received checksum against calculated checksum
+   *
+   * @param data Pointer to data to validate
+   * @param len Length of data in bytes
+   * @param received_checksum Checksum received with data
+   * @return true if checksum is valid, false otherwise
+   */
+  bool validateChecksum(const uint8_t *data, size_t len, uint16_t received_checksum);
+
+  /**
+   * @brief Common packet handling for received packets
+   *
+   * Implements the standard pattern used by all bridges:
+   * - Check if packet was seen before using _seen_packets.hasSeen()
+   * - Queue packet for mesh processing if not seen before
+   * - Free packet if already seen to prevent duplicates
+   *
+   * @param packet The received mesh packet
+   */
+  void handleReceivedPacket(mesh::Packet *packet);
+};