// Copyright (c) 2014-2016 The Bitcoin Core developers
// Copyright (c) 2017-2025 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#pragma once

#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif

#include <compat/byteswap.h>

#include <bit>
#include <cstdint>

#if defined(HAVE_ENDIAN_H)
#include <endian.h>
#elif defined(HAVE_SYS_ENDIAN_H)
#include <sys/endian.h>
#endif

#ifndef HAVE_CONFIG_H
// While not technically a supported configuration, defaulting to defining these
// DECLs when we were compiled without autotools makes it easier for other build
// systems to build things like libbitcoinconsensus for strange targets.
#ifdef htobe16
#define HAVE_DECL_HTOBE16 1
#endif
#ifdef htole16
#define HAVE_DECL_HTOLE16 1
#endif
#ifdef be16toh
#define HAVE_DECL_BE16TOH 1
#endif
#ifdef le16toh
#define HAVE_DECL_LE16TOH 1
#endif

#ifdef htobe32
#define HAVE_DECL_HTOBE32 1
#endif
#ifdef htole32
#define HAVE_DECL_HTOLE32 1
#endif
#ifdef be32toh
#define HAVE_DECL_BE32TOH 1
#endif
#ifdef le32toh
#define HAVE_DECL_LE32TOH 1
#endif

#ifdef htobe64
#define HAVE_DECL_HTOBE64 1
#endif
#ifdef htole64
#define HAVE_DECL_HTOLE64 1
#endif
#ifdef be64toh
#define HAVE_DECL_BE64TOH 1
#endif
#ifdef le64toh
#define HAVE_DECL_LE64TOH 1
#endif

#endif // HAVE_CONFIG_H

#if defined(WORDS_BIGENDIAN)
static_assert(std::endian::native == std::endian::big, "Check that build system and compiler agree on endianness");

#if HAVE_DECL_HTOBE16 == 0
inline uint16_t htobe16(uint16_t host_16bits) {
    return host_16bits;
}
#endif // HAVE_DECL_HTOBE16

#if HAVE_DECL_HTOLE16 == 0
inline uint16_t htole16(uint16_t host_16bits) {
    return bswap_16(host_16bits);
}
#endif // HAVE_DECL_HTOLE16

#if HAVE_DECL_BE16TOH == 0
inline uint16_t be16toh(uint16_t big_endian_16bits) {
    return big_endian_16bits;
}
#endif // HAVE_DECL_BE16TOH

#if HAVE_DECL_LE16TOH == 0
inline uint16_t le16toh(uint16_t little_endian_16bits) {
    return bswap_16(little_endian_16bits);
}
#endif // HAVE_DECL_LE16TOH

#if HAVE_DECL_HTOBE32 == 0
inline uint32_t htobe32(uint32_t host_32bits) {
    return host_32bits;
}
#endif // HAVE_DECL_HTOBE32

#if HAVE_DECL_HTOLE32 == 0
inline uint32_t htole32(uint32_t host_32bits) {
    return bswap_32(host_32bits);
}
#endif // HAVE_DECL_HTOLE32

#if HAVE_DECL_BE32TOH == 0
inline uint32_t be32toh(uint32_t big_endian_32bits) {
    return big_endian_32bits;
}
#endif // HAVE_DECL_BE32TOH

#if HAVE_DECL_LE32TOH == 0
inline uint32_t le32toh(uint32_t little_endian_32bits) {
    return bswap_32(little_endian_32bits);
}
#endif // HAVE_DECL_LE32TOH

#if HAVE_DECL_HTOBE64 == 0
inline uint64_t htobe64(uint64_t host_64bits) {
    return host_64bits;
}
#endif // HAVE_DECL_HTOBE64

#if HAVE_DECL_HTOLE64 == 0
inline uint64_t htole64(uint64_t host_64bits) {
    return bswap_64(host_64bits);
}
#endif // HAVE_DECL_HTOLE64

#if HAVE_DECL_BE64TOH == 0
inline uint64_t be64toh(uint64_t big_endian_64bits) {
    return big_endian_64bits;
}
#endif // HAVE_DECL_BE64TOH

#if HAVE_DECL_LE64TOH == 0
inline uint64_t le64toh(uint64_t little_endian_64bits) {
    return bswap_64(little_endian_64bits);
}
#endif // HAVE_DECL_LE64TOH

#else // WORDS_BIGENDIAN
static_assert(std::endian::native == std::endian::little, "Check that build system and compiler agree on endianness");

#if HAVE_DECL_HTOBE16 == 0
inline uint16_t htobe16(uint16_t host_16bits) {
    return bswap_16(host_16bits);
}
#endif // HAVE_DECL_HTOBE16

#if HAVE_DECL_HTOLE16 == 0
inline uint16_t htole16(uint16_t host_16bits) {
    return host_16bits;
}
#endif // HAVE_DECL_HTOLE16

#if HAVE_DECL_BE16TOH == 0
inline uint16_t be16toh(uint16_t big_endian_16bits) {
    return bswap_16(big_endian_16bits);
}
#endif // HAVE_DECL_BE16TOH

#if HAVE_DECL_LE16TOH == 0
inline uint16_t le16toh(uint16_t little_endian_16bits) {
    return little_endian_16bits;
}
#endif // HAVE_DECL_LE16TOH

#if HAVE_DECL_HTOBE32 == 0
inline uint32_t htobe32(uint32_t host_32bits) {
    return bswap_32(host_32bits);
}
#endif // HAVE_DECL_HTOBE32

#if HAVE_DECL_HTOLE32 == 0
inline uint32_t htole32(uint32_t host_32bits) {
    return host_32bits;
}
#endif // HAVE_DECL_HTOLE32

#if HAVE_DECL_BE32TOH == 0
inline uint32_t be32toh(uint32_t big_endian_32bits) {
    return bswap_32(big_endian_32bits);
}
#endif // HAVE_DECL_BE32TOH

#if HAVE_DECL_LE32TOH == 0
inline uint32_t le32toh(uint32_t little_endian_32bits) {
    return little_endian_32bits;
}
#endif // HAVE_DECL_LE32TOH

#if HAVE_DECL_HTOBE64 == 0
inline uint64_t htobe64(uint64_t host_64bits) {
    return bswap_64(host_64bits);
}
#endif // HAVE_DECL_HTOBE64

#if HAVE_DECL_HTOLE64 == 0
inline uint64_t htole64(uint64_t host_64bits) {
    return host_64bits;
}
#endif // HAVE_DECL_HTOLE64

#if HAVE_DECL_BE64TOH == 0
inline uint64_t be64toh(uint64_t big_endian_64bits) {
    return bswap_64(big_endian_64bits);
}
#endif // HAVE_DECL_BE64TOH

#if HAVE_DECL_LE64TOH == 0
inline uint64_t le64toh(uint64_t little_endian_64bits) {
    return little_endian_64bits;
}
#endif // HAVE_DECL_LE64TOH

#endif // WORDS_BIGENDIAN
