// SPDX-License-Identifier: MIT
#ifndef J1939_H
#define J1939_H

#include <cstdint>

/** Extract an 18-bit PGN from a normalized 29-bit ID explicitly interpreted as J1939.
 * Priority and source address are excluded. PDU1 also excludes destination address.
 * Both data-page bits are retained; this does not validate the J1939 protocol.
 */
inline std::uint32_t ExtractJ1939Pgn(std::uint32_t canId) {
    const std::uint32_t pf = (canId >> 16U) & 0xFFU;
    const std::uint32_t pgn = (canId >> 8U) & 0x3FFFFU;
    return pf < 240U ? pgn & 0x3FF00U : pgn;
}

#endif /* J1939_H */