#pragma once

#include <cstddef>
#include <cstdint>
#include <string>

namespace roro::meshtastic {

constexpr uint32_t kBroadcast = 0xFFFFFFFF;

// The 16 bytes every Meshtastic packet starts with, sent in clear (little-endian). The payload
// after it is encrypted with the Channel's key.
struct PacketHeader {
    uint32_t to = 0, from = 0, id = 0;
    uint8_t flags = 0;
    uint8_t channelHash = 0;  // the Channel's name and key folded into a byte (see channelHash())
    uint8_t nextHop = 0;      // last byte of the Node meant to relay it next; 0 when flooding
    uint8_t relayNode = 0;    // last byte of the Node that relayed it to us

    uint8_t hopLimit() const { return flags & 0x07; }
    bool wantAck() const { return flags & 0x08; }
    bool viaMqtt() const { return flags & 0x10; }
    uint8_t hopStart() const { return flags >> 5; }
    bool broadcast() const { return to == kBroadcast; }
    // How many times it was relayed before we heard it; -1 when the sender didn't say (hop start 0).
    int hopsAway() const { return hopStart() == 0 ? -1 : hopStart() - hopLimit(); }
};

constexpr size_t kHeaderSize = 16;

bool parseHeader(const uint8_t* data, size_t len, PacketHeader& out);

// "!12345678", as Meshtastic writes node numbers; "all" for broadcast.
std::string nodeId(uint32_t node);

}  // namespace roro::meshtastic