priv impl and scaffold for driver

CMakeLists.txt

@@ -1,5 +1,5 @@
 idf_component_register(
-    SRCS "bbnow_pub.cpp"
+    SRCS "bbnow_driver.cpp" "bbnow_priv.cpp" "bbnow_pub.cpp"
     INCLUDE_DIRS "include" "."
     # PRIV_REQUIRES 
 )

bbnow_driver.cpp

@@ -0,0 +1,20 @@
+#include "bbnow_driver.hpp"
+
+esp_err_t BBNowDriver::init()
+{
+    return ESP_OK;
+}
+
+esp_err_t BBNowDriver::deinit()
+{
+    return ESP_OK;
+}
+
+esp_err_t BBNowDriver::send(
+    const MacAddress& destination,
+    const uint8_t* data,
+    size_t size
+)
+{
+    return ESP_OK;
+}

bbnow_priv.cpp

@@ -0,0 +1,360 @@
+#include "bbnow_priv.hpp"
+
+#include <cassert>
+#include <esp_log.h>
+
+const static char TAG[] = "bbnow_priv";
+
+size_t BBNowPrivPacket::serialize_size() const {
+    switch (this->packet_type) {
+        case BBNowPrivPacketType::NONE:
+            return -1;
+
+        case BBNowPrivPacketType::ACK:
+            return BBNowPrivPacket::ACK_PACKET_SIZE;
+
+        case BBNowPrivPacketType::DISCOVERY_RESPONSE:
+            return BBNowPrivPacket::DISCOVERY_RESPONSE_PACKET_SIZE;
+
+        case BBNowPrivPacketType::EXPANDER_MESSAGE: {
+            const auto& data =
+                std::get<BBNowPrivExpanderMessageData>(
+                    this->packet_data
+                );
+
+            return sizeof(BBNowPrivPacketType) +
+                   sizeof(uint16_t) +
+                   data.data.size();
+        }
+
+        case BBNowPrivPacketType::INFO_QUERY:
+            return BBNowPrivPacket::INFO_QUERY_PACKET_SIZE;
+            
+        default:
+            return -1;
+    }
+
+    return -1;
+}
+
+std::vector<uint8_t> BBNowPrivPacket::serialize() const {
+    auto buf = std::vector<uint8_t>();
+
+    if (this->serialize_size() == static_cast<size_t>(-1)) {
+        return buf;
+    }
+
+    this->serialize_into(buf);
+    return buf;
+}
+
+size_t BBNowPrivPacket::serialize_into(
+    std::vector<uint8_t>& buf
+) const {
+    size_t initial_size = buf.size();
+    size_t size = this->serialize_size();
+
+    if (size == static_cast<size_t>(-1)) {
+        return 0;
+    }
+
+    buf.reserve(initial_size + size);
+
+    // Push packet type.
+    static_assert(
+        sizeof(BBNowPrivPacketType) == 2,
+        "expect packet type to be 2 bytes"
+    );
+
+    uint16_t packet_type =
+        static_cast<uint16_t>(this->packet_type);
+
+    buf.push_back((packet_type >> 8) & 0xFF);
+    buf.push_back((packet_type >> 0) & 0xFF);
+
+    // Push sequence number.
+    static_assert(
+        sizeof(this->sequence) == 2,
+        "expect sequence number to be 2 bytes"
+    );
+
+    buf.push_back((this->sequence >> 8) & 0xFF);
+    buf.push_back((this->sequence >> 0) & 0xFF);
+
+    switch (this->packet_type) {
+        case BBNowPrivPacketType::NONE:
+            break;
+
+        case BBNowPrivPacketType::ACK:
+            break;
+
+        case BBNowPrivPacketType::DISCOVERY_RESPONSE: {
+            const auto& data =
+                std::get<BBNowPrivDiscoveryResponseData>(
+                    this->packet_data
+                );
+
+            static_assert(
+                sizeof(data.expantion_type) == 2,
+                "expect expansion type to be 2 bytes"
+            );
+
+            uint16_t expantion_type =
+                static_cast<uint16_t>(data.expantion_type);
+
+            buf.push_back((expantion_type >> 8) & 0xFF);
+            buf.push_back((expantion_type >> 0) & 0xFF);
+
+            break;
+        }
+
+        case BBNowPrivPacketType::EXPANDER_MESSAGE: {
+            const auto& data =
+                std::get<BBNowPrivExpanderMessageData>(
+                    this->packet_data
+                );
+
+            buf.insert(
+                buf.end(),
+                data.data.begin(),
+                data.data.end()
+            );
+
+            break;
+        }
+
+        case BBNowPrivPacketType::INFO_QUERY: {
+            const auto& data =
+                std::get<BBNowPrivInfoQueryData>(
+                    this->packet_data
+                );
+
+            static_assert(
+                sizeof(data) == 1,
+                "expect info query type to be 1 byte"
+            );
+            buf.push_back(data.battery_percentage);
+
+            break;
+        }
+    }
+
+    assert(buf.size() - initial_size == size);
+    return size;
+}
+
+std::optional<BBNowPrivPacket>
+BBNowPrivPacket::deserialize(
+    std::span<const uint8_t> bytes
+) {
+    // Packet type + sequence number.
+    static_assert(
+        sizeof(BBNowPrivPacketType) + sizeof(uint16_t) == 4,
+        "expect packet type and sequence number to be 4 bytes"
+    );
+
+    if (bytes.size() < 4) {
+        ESP_LOGW(
+            TAG,
+            "packet not long enough for priv packet"
+        );
+        return std::nullopt;
+    }
+
+    // Read packet type.
+    uint16_t packet_type =
+        ((uint16_t)bytes[0] << 8) |
+        ((uint16_t)bytes[1] << 0);
+
+    BBNowPrivPacket packet;
+
+    packet.packet_type =
+        static_cast<BBNowPrivPacketType>(packet_type);
+
+    if (packet.packet_type == BBNowPrivPacketType::NONE) {
+        ESP_LOGW(
+            TAG,
+            "BBNowPrivPacketType was NONE! discarding"
+        );
+        return std::nullopt;
+    }
+
+    if (packet.packet_type > BBNowPrivPacketType::MAX) {
+        ESP_LOGW(
+            TAG,
+            "BBNowPrivPacketType not in range! discarding"
+        );
+        return std::nullopt;
+    }
+
+    // Read sequence number.
+    packet.sequence =
+        ((uint16_t)bytes[2] << 8) |
+        ((uint16_t)bytes[3] << 0);
+
+    switch (packet.packet_type) {
+        case BBNowPrivPacketType::ACK: {
+            if (bytes.size() < ACK_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "ACK packet not long enough"
+                );
+                return std::nullopt;
+            }
+
+            if (bytes.size() > ACK_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "ACK packet longer than expected, "
+                    "decoding anyway"
+                );
+            }
+
+            packet.packet_data = BBNowPrivAckData{};
+            break;
+        }
+
+        case BBNowPrivPacketType::DISCOVERY_RESPONSE: {
+            if (bytes.size() < DISCOVERY_RESPONSE_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "discovery response packet not long enough"
+                );
+                return std::nullopt;
+            }
+
+            if (bytes.size() > DISCOVERY_RESPONSE_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "discovery response packet longer than expected, "
+                    "decoding anyway"
+                );
+            }
+
+            uint16_t expantion_type =
+                ((uint16_t)bytes[4] << 8) |
+                ((uint16_t)bytes[5] << 0);
+
+            auto data = BBNowPrivDiscoveryResponseData{
+                .expantion_type =
+                    static_cast<BlkBoxExpantion>(expantion_type)
+            };
+
+            if (data.expantion_type > BlkBoxExpantion::MAX) {
+                ESP_LOGW(
+                    TAG,
+                    "BlkBoxExpantion not in range! discarding"
+                );
+                return std::nullopt;
+            }
+
+            packet.packet_data = std::move(data);
+            break;
+        }
+
+        case BBNowPrivPacketType::EXPANDER_MESSAGE: {
+            // Everything after the 4-byte header is the message.
+            auto data = BBNowPrivExpanderMessageData{
+                .data = std::vector<uint8_t>(
+                    bytes.begin() + 4,
+                    bytes.end()
+                )
+            };
+
+            packet.packet_data = std::move(data);
+            break;
+        }
+
+        case BBNowPrivPacketType::INFO_QUERY: {
+            constexpr size_t INFO_QUERY_PACKET_SIZE =
+                sizeof(BBNowPrivPacketType) +
+                sizeof(uint16_t) +
+                sizeof(BBNowPrivInfoQueryData);
+
+            if (bytes.size() < INFO_QUERY_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "info query packet not long enough"
+                );
+                return std::nullopt;
+            }
+
+            if (bytes.size() > INFO_QUERY_PACKET_SIZE) {
+                ESP_LOGW(
+                    TAG,
+                    "info query packet longer than expected, "
+                    "decoding anyway"
+                );
+            }
+
+            BBNowPrivInfoQueryData data{
+                .battery_percentage = bytes[4]
+            };
+
+            packet.packet_data = data;
+            break;
+        }
+
+        case BBNowPrivPacketType::NONE:
+            return std::nullopt;
+    }
+
+    return packet;
+}
+
+BBNowPrivPacket BBNowPrivPacket::new_ack(
+    uint16_t sequence
+) {
+    BBNowPrivPacket packet;
+
+    packet.packet_type = BBNowPrivPacketType::ACK;
+    packet.sequence = sequence;
+    packet.packet_data = BBNowPrivAckData{};
+
+    return packet;
+}
+
+BBNowPrivPacket BBNowPrivPacket::new_discovery_response(
+    uint16_t sequence,
+    BBNowPrivDiscoveryResponseData data
+) {
+    BBNowPrivPacket packet;
+
+    packet.packet_type =
+        BBNowPrivPacketType::DISCOVERY_RESPONSE;
+
+    packet.sequence = sequence;
+    packet.packet_data = std::move(data);
+
+    return packet;
+}
+
+BBNowPrivPacket BBNowPrivPacket::new_expander_message(
+    uint16_t sequence,
+    BBNowPrivExpanderMessageData data
+) {
+    BBNowPrivPacket packet;
+
+    packet.packet_type =
+        BBNowPrivPacketType::EXPANDER_MESSAGE;
+
+    packet.sequence = sequence;
+    packet.packet_data = std::move(data);
+
+    return packet;
+}
+
+BBNowPrivPacket BBNowPrivPacket::new_info_query(
+    uint16_t sequence,
+    BBNowPrivInfoQueryData data
+) {
+    BBNowPrivPacket packet;
+
+    packet.packet_type =
+        BBNowPrivPacketType::INFO_QUERY;
+
+    packet.sequence = sequence;
+    packet.packet_data = std::move(data);
+
+    return packet;
+}

include/bb_expantions.hpp

@@ -5,6 +5,8 @@
 
 #include <stdint.h>
 
+#define EXPANDER_DEVICE_NAME_MAX_LEN 32
+
 /// The expantion device ids in the BLK_BOX ecosystem.
 enum class BlkBoxExpantion: uint16_t {
     NONE = 0,

include/bbnow_driver.hpp

@@ -0,0 +1,74 @@
+/// Generic code for driving a BBNOW interface.
+
+#ifndef _BBNOW_DRIVER_HPP
+#define _BBNOW_DRIVER_HPP
+
+#include <array>
+#include <cstdint>
+#include <span>
+#include <string>
+#include <vector>
+
+#include "esp_err.h"
+
+#include "bb_expantions.hpp"
+#include "bbnow_pub.hpp"
+#include "bbnow_priv.hpp"
+
+class BBNowDriver {
+public:
+    using MacAddress = std::array<uint8_t, 6>;
+
+    struct PairedExpander {
+        MacAddress mac;
+        std::string name;
+        BlkBoxExpantion type;
+    };
+
+    static constexpr uint8_t DEFAULT_CHANNEL = 6;
+
+    static esp_err_t init();
+    static esp_err_t deinit();
+
+    static esp_err_t send_pub(const BBNowPubPacket& packet);
+    static bool has_pub();
+    static bool recv_pub(BBNowPubPacket& packet);
+
+    static esp_err_t send_priv(
+        const MacAddress& destination,
+        const BBNowPrivPacket& packet
+    );
+    static bool has_priv();
+    static bool recv_priv(
+        MacAddress& source,
+        BBNowPrivPacket& packet
+    );
+
+    /// Broadcast a discovery packet.
+    static size_t send_discovery(
+        BlkBoxExpantion type
+    );
+
+    static esp_err_t pair_expander(
+        BlkBoxExpantion type,
+        const MacAddress& mac
+    );
+
+    static esp_err_t unpair_expander(
+        const MacAddress& mac
+    );
+
+    static std::span<const PairedExpander> get_paired_expanders();
+
+private:
+    static constexpr MacAddress BROADCAST_MAC = {
+        0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff
+    };
+
+    static bool initialized_;
+
+    static std::vector<PairedExpander> paired_expanders;
+};
+
+#endif /* _BBNOW_DRIVER_HPP */

include/bbnow_priv.hpp

@@ -4,9 +4,49 @@
 #define _BBNOW_PRIV_H
 
 #include <stdint.h>
+#include <vector>
+#include <optional>
+#include <span>
+#include <variant>
 
-#define EXPANDER_DEVICE_NAME_MAX_LEN 32
+#include "bb_expantions.hpp"
 
+///////////////////////////////////////
+// ACK                              //
+/////////////////////////////////////
+/// The data associated with the `ACK` type.
+struct BBNowPrivAckData {
+};
+
+///////////////////////////////////////
+// DISCOVERY RESPONSE               //
+/////////////////////////////////////
+/// The data associated with the `DISCOVERY_RESPONSE` type.
+struct BBNowPrivDiscoveryResponseData {
+    BlkBoxExpantion expantion_type{};
+};
+
+///////////////////////////////////////
+// EXPANDER MESSAGE                 //
+/////////////////////////////////////
+/// The data associated with the `EXPANDER_MESSAGE` type.
+struct BBNowPrivExpanderMessageData {
+    // TODO: this should get flattened into a concrete type, an enum over the expander types.
+    std::vector<uint8_t> data;
+};
+
+///////////////////////////////////////
+// INFO QUERY                       //
+/////////////////////////////////////
+/// The data associated with the `INFO_QUERY` type.
+struct BBNowPrivInfoQueryData {
+    uint8_t battery_percentage;
+    // TODO: add other status fields that may be useful to query.
+};
+
+///////////////////////////////////////
+// PRIV PACKET                      //
+/////////////////////////////////////
 /// The packet type for `BBNowPrivPacket`s.
 enum class BBNowPrivPacketType: uint16_t {
     NONE = 0,
@@ -14,7 +54,93 @@ enum class BBNowPrivPacketType: uint16_t {
     // TODO: we will need to add more here for handshaking in the future.
     DISCOVERY_RESPONSE = 2,
     EXPANDER_MESSAGE = 3,
-    MAX = 3,
+    INFO_QUERY = 4,
+    MAX = 4,
+};
+
+/// The data field for the packet.
+using BBNowPrivPacketData = std::variant<
+    std::monostate,
+    BBNowPrivAckData,
+    BBNowPrivDiscoveryResponseData,
+    BBNowPrivExpanderMessageData,
+    BBNowPrivInfoQueryData
+>;
+
+struct BBNowPrivPacket {
+    /// ACK packet size.
+    const static size_t ACK_PACKET_SIZE = 4;
+    static_assert(
+        ACK_PACKET_SIZE == sizeof(BBNowPrivPacketType) + sizeof(uint16_t),
+        "ACK packet size should match it's data size"
+    );
+
+    /// Discovery response packet size.
+    const static size_t DISCOVERY_RESPONSE_PACKET_SIZE = 6;
+    static_assert(
+        DISCOVERY_RESPONSE_PACKET_SIZE == sizeof(BBNowPrivPacketType) +
+        sizeof(uint16_t) +
+        sizeof(BBNowPrivDiscoveryResponseData),
+        "Discovery response packet size should match it's data size"
+    );
+
+    /// Info query packet size.
+    const static size_t INFO_QUERY_PACKET_SIZE = 5;
+    static_assert(
+        INFO_QUERY_PACKET_SIZE ==
+            sizeof(BBNowPrivPacketType) +
+            sizeof(uint16_t) +
+            sizeof(BBNowPrivInfoQueryData),
+        "Info query packet size should match its data size"
+    );
+
+    /// The type of packet this is.
+    BBNowPrivPacketType packet_type{};
+
+    /// Sequence number associated with this packet.
+    uint16_t sequence{};
+
+    /// The data held by the packet.
+    BBNowPrivPacketData packet_data{};
+
+    /// The size of the serialized packet (in bytes).
+    size_t serialize_size() const;
+
+    /// Serializes the packet to a vector.
+    std::vector<uint8_t> serialize() const;
+
+    /// Serializes the packet into the given vector.
+    ///
+    /// Returns the number of bytes written into the buffer.
+    size_t serialize_into(std::vector<uint8_t>& buf) const;
+
+    /// Deserializes a packet from the given bytes.
+    static std::optional<BBNowPrivPacket>
+    deserialize(std::span<const uint8_t> bytes);
+
+    /// Constructs an empty packet.
+    BBNowPrivPacket() = default;
+
+    /// Constructs a new `ACK` packet.
+    static BBNowPrivPacket new_ack(uint16_t sequence);
+
+    /// Constructs a new `DISCOVERY_RESPONSE` packet.
+    static BBNowPrivPacket new_discovery_response(
+        uint16_t sequence,
+        BBNowPrivDiscoveryResponseData data
+    );
+
+    /// Constructs a new `EXPANDER_MESSAGE` packet.
+    static BBNowPrivPacket new_expander_message(
+        uint16_t sequence,
+        BBNowPrivExpanderMessageData data
+    );
+
+    /// Constructs a new `INFO_QUERY` packet.
+    static BBNowPrivPacket new_info_query(
+        uint16_t sequence, 
+        BBNowPrivInfoQueryData data
+    );
 };
 
 #endif /* _BBNOW_PRIV_H */

include/bbnow_pub.hpp

@@ -7,6 +7,7 @@
 #include <vector>
 #include <optional>
 #include <span>
+#include <variant>
 
 #include "bb_expantions.hpp"
 
@@ -30,10 +31,11 @@ enum class BBNowPubPacketType: uint16_t {
     MAX = 1,
 };
 
-/// The data field for the packet
+/// The data field for the packet.
-union BlkBoxNowPubPacketData {
+using BlkBoxNowPubPacketData = std::variant<
-    BlkBoxNowPubDiscoveryData discovery;
+    std::monostate,
-};
+    BlkBoxNowPubDiscoveryData
+>;
 
 struct BBNowPubPacket {
     // "bbnp" in ascii