include(CheckIncludeFile)
include(CheckIncludeFiles)
include(CheckSymbolExists)
include(CheckFunctionExists)
include(CheckLibraryExists)
include(CheckTypeSize)
include(CheckStructHasMember)
include(TestBigEndian)

set(PACKAGE ${PROJECT_NAME})
set(VERSION ${PROJECT_VERSION})
set(SYSCONFDIR ${CMAKE_INSTALL_SYSCONFDIR})

set(BINARYDIR ${CMAKE_BINARY_DIR})
set(SOURCEDIR ${CMAKE_SOURCE_DIR})

function(COMPILER_DUMPVERSION _OUTPUT_VERSION)
    # Remove whitespaces from the argument.
    # This is needed for CC="ccache gcc" cmake ..
    string(REPLACE " " "" _C_COMPILER_ARG "${CMAKE_C_COMPILER_ARG1}")

    execute_process(
        COMMAND
            ${CMAKE_C_COMPILER} ${_C_COMPILER_ARG} -dumpversion
        OUTPUT_VARIABLE _COMPILER_VERSION
    )

    string(REGEX REPLACE "([0-9])\\.([0-9])(\\.[0-9])?" "\\1\\2"
           _COMPILER_VERSION "${_COMPILER_VERSION}")

    set(${_OUTPUT_VERSION} ${_COMPILER_VERSION} PARENT_SCOPE)
endfunction()

if(CMAKE_COMPILER_IS_GNUCC AND NOT MINGW AND NOT OS2)
    compiler_dumpversion(GNUCC_VERSION)
    if (NOT GNUCC_VERSION EQUAL 34)
        set(CMAKE_REQUIRED_FLAGS "-fvisibility=hidden")
        check_c_source_compiles(
"void __attribute__((visibility(\"default\"))) test() {}
int main(void){ return 0; }
" WITH_VISIBILITY_HIDDEN)
        unset(CMAKE_REQUIRED_FLAGS)
    endif (NOT GNUCC_VERSION EQUAL 34)
endif(CMAKE_COMPILER_IS_GNUCC AND NOT MINGW AND NOT OS2)

# HEADER FILES
check_function_exists(argp_parse HAVE_ARGP_PARSE)

set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${ARGP_INCLUDE_DIR})
check_include_file(argp.h HAVE_ARGP_H)
unset(CMAKE_REQUIRED_INCLUDES)

check_include_file(pty.h HAVE_PTY_H)
check_include_file(utmp.h HAVE_UTMP_H)
check_include_file(termios.h HAVE_TERMIOS_H)
check_include_file(unistd.h HAVE_UNISTD_H)
check_include_file(stdint.h HAVE_STDINT_H)
check_include_file(util.h HAVE_UTIL_H)
check_include_file(libutil.h HAVE_LIBUTIL_H)
check_include_file(sys/time.h HAVE_SYS_TIME_H)
check_include_file(sys/utime.h HAVE_SYS_UTIME_H)
check_include_file(sys/param.h HAVE_SYS_PARAM_H)
check_include_file(arpa/inet.h HAVE_ARPA_INET_H)
check_include_file(byteswap.h HAVE_BYTESWAP_H)
check_include_file(glob.h HAVE_GLOB_H)
check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
check_include_file(ifaddrs.h HAVE_IFADDRS_H)

if (WIN32)
  check_include_file(io.h HAVE_IO_H)

  check_include_files("winsock2.h;ws2tcpip.h;wspiapi.h" HAVE_WSPIAPI_H)
  if (NOT HAVE_WSPIAPI_H)
    message(STATUS "WARNING: Without wspiapi.h, this build will only work on Windows XP and newer versions")
  endif (NOT HAVE_WSPIAPI_H)
  check_include_files("winsock2.h;ws2tcpip.h" HAVE_WS2TCPIP_H)
endif (WIN32)

if (OPENSSL_FOUND)
    set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
    set(CMAKE_REQUIRED_LIBRARIES OpenSSL::Crypto)

    check_include_file(openssl/des.h HAVE_OPENSSL_DES_H)
    if (NOT HAVE_OPENSSL_DES_H)
        message(FATAL_ERROR "Could not detect openssl/des.h")
    endif()

    check_include_file(openssl/aes.h HAVE_OPENSSL_AES_H)
    if (NOT HAVE_OPENSSL_AES_H)
        message(FATAL_ERROR "Could not detect openssl/aes.h")
    endif()

    if (WITH_BLOWFISH_CIPHER)
        check_include_file(openssl/blowfish.h HAVE_BLOWFISH)
    endif()

    check_include_file(openssl/ecdh.h HAVE_OPENSSL_ECDH_H)
    check_include_file(openssl/ec.h HAVE_OPENSSL_EC_H)
    check_include_file(openssl/ecdsa.h HAVE_OPENSSL_ECDSA_H)

    check_function_exists(EVP_KDF_CTX_new_id HAVE_OPENSSL_EVP_KDF_CTX_NEW_ID)
    check_function_exists(EVP_KDF_CTX_new HAVE_OPENSSL_EVP_KDF_CTX_NEW)
    check_function_exists(FIPS_mode HAVE_OPENSSL_FIPS_MODE)
    check_function_exists(RAND_priv_bytes HAVE_OPENSSL_RAND_PRIV_BYTES)
    check_function_exists(EVP_chacha20 HAVE_OPENSSL_EVP_CHACHA20)

    unset(CMAKE_REQUIRED_INCLUDES)
    unset(CMAKE_REQUIRED_LIBRARIES)
endif()

if (CMAKE_HAVE_PTHREAD_H)
  set(HAVE_PTHREAD_H 1)
endif (CMAKE_HAVE_PTHREAD_H)

if (NOT WITH_GCRYPT AND NOT WITH_MBEDTLS)
    if (HAVE_OPENSSL_EC_H AND HAVE_OPENSSL_ECDSA_H)
        set(HAVE_OPENSSL_ECC 1)
    endif (HAVE_OPENSSL_EC_H AND HAVE_OPENSSL_ECDSA_H)

    if (HAVE_OPENSSL_ECC)
        set(HAVE_ECC 1)
    endif (HAVE_OPENSSL_ECC)

    if (HAVE_OPENSSL_EVP_KDF_CTX_NEW_ID OR HAVE_OPENSSL_EVP_KDF_CTX_NEW)
        set(HAVE_OPENSSL_EVP_KDF_CTX 1)
    endif (HAVE_OPENSSL_EVP_KDF_CTX_NEW_ID OR HAVE_OPENSSL_EVP_KDF_CTX_NEW)

endif ()

# FUNCTIONS

check_function_exists(isblank HAVE_ISBLANK)
check_function_exists(strncpy HAVE_STRNCPY)
check_function_exists(strndup HAVE_STRNDUP)
check_function_exists(strtoull HAVE_STRTOULL)
check_function_exists(explicit_bzero HAVE_EXPLICIT_BZERO)
check_function_exists(memset_s HAVE_MEMSET_S)

if (HAVE_GLOB_H)
    check_struct_has_member(glob_t gl_flags glob.h HAVE_GLOB_GL_FLAGS_MEMBER)
    check_function_exists(glob HAVE_GLOB)
endif (HAVE_GLOB_H)

if (NOT WIN32)
  check_function_exists(vsnprintf HAVE_VSNPRINTF)
  check_function_exists(snprintf HAVE_SNPRINTF)
endif (NOT WIN32)

if (WIN32)
    check_symbol_exists(vsnprintf "stdio.h" HAVE_VSNPRINTF)
    check_symbol_exists(snprintf "stdio.h" HAVE_SNPRINTF)

    check_symbol_exists(_vsnprintf_s "stdio.h" HAVE__VSNPRINTF_S)
    check_symbol_exists(_vsnprintf "stdio.h" HAVE__VSNPRINTF)
    check_symbol_exists(_snprintf "stdio.h" HAVE__SNPRINTF)
    check_symbol_exists(_snprintf_s "stdio.h" HAVE__SNPRINTF_S)

    if (HAVE_WSPIAPI_H OR HAVE_WS2TCPIP_H)
        check_symbol_exists(ntohll winsock2.h HAVE_NTOHLL)
        check_symbol_exists(htonll winsock2.h HAVE_HTONLL)

        set(CMAKE_REQUIRED_LIBRARIES ws2_32)
        check_symbol_exists(select "winsock2.h;ws2tcpip.h" HAVE_SELECT)
        check_symbol_exists(poll "winsock2.h;ws2tcpip.h" HAVE_SELECT)
        # The getaddrinfo function is defined to the WspiapiGetAddrInfo inline function
        check_symbol_exists(getaddrinfo "winsock2.h;ws2tcpip.h" HAVE_GETADDRINFO)
        unset(CMAKE_REQUIRED_LIBRARIES)
    endif (HAVE_WSPIAPI_H OR HAVE_WS2TCPIP_H)

    check_function_exists(_strtoui64 HAVE__STRTOUI64)

    set(HAVE_SELECT TRUE)

    check_symbol_exists(SecureZeroMemory "windows.h" HAVE_SECURE_ZERO_MEMORY)
else (WIN32)
    check_function_exists(poll HAVE_POLL)
    check_function_exists(select HAVE_SELECT)
    check_function_exists(getaddrinfo HAVE_GETADDRINFO)

    check_symbol_exists(ntohll arpa/inet.h HAVE_NTOHLL)
    check_symbol_exists(htonll arpa/inet.h HAVE_HTONLL)
endif (WIN32)


if (UNIX)
    if (NOT LINUX)
        # libsocket (Solaris)
        check_library_exists(socket getaddrinfo "" HAVE_LIBSOCKET)
        if (HAVE_LIBSOCKET)
            set(HAVE_GETADDRINFO TRUE)
            set(_REQUIRED_LIBRARIES ${_REQUIRED_LIBRARIES} socket)
        endif (HAVE_LIBSOCKET)

        # libnsl/inet_pton (Solaris)
        check_library_exists(nsl inet_pton "" HAVE_LIBNSL)
        if (HAVE_LIBNSL)
            set(_REQUIRED_LIBRARIES ${_REQUIRED_LIBRARIES} nsl)
        endif (HAVE_LIBNSL)

        # librt
        check_library_exists(rt nanosleep "" HAVE_LIBRT)
    endif (NOT LINUX)

    check_library_exists(rt clock_gettime "" HAVE_CLOCK_GETTIME)
    if (HAVE_LIBRT OR HAVE_CLOCK_GETTIME)
        set(_REQUIRED_LIBRARIES ${_REQUIRED_LIBRARIES} rt)
    endif (HAVE_LIBRT OR HAVE_CLOCK_GETTIME)

    check_library_exists(util forkpty "" HAVE_LIBUTIL)
    check_function_exists(cfmakeraw HAVE_CFMAKERAW)
    check_function_exists(__strtoull HAVE___STRTOULL)
endif (UNIX)

set(LIBSSH_REQUIRED_LIBRARIES ${_REQUIRED_LIBRARIES} CACHE INTERNAL "libssh required system libraries")

# LIBRARIES
if (OPENSSL_FOUND)
  set(HAVE_LIBCRYPTO 1)
endif (OPENSSL_FOUND)

if (GCRYPT_FOUND)
    set(HAVE_LIBGCRYPT 1)
    if (GCRYPT_VERSION VERSION_GREATER "1.4.6")
        set(HAVE_GCRYPT_ECC 1)
        set(HAVE_ECC 1)
    endif (GCRYPT_VERSION VERSION_GREATER "1.4.6")
    if (NOT GCRYPT_VERSION VERSION_LESS "1.7.0")
        set(HAVE_GCRYPT_CHACHA_POLY 1)
    endif (NOT GCRYPT_VERSION VERSION_LESS "1.7.0")
endif (GCRYPT_FOUND)

if (MBEDTLS_FOUND)
    set(HAVE_LIBMBEDCRYPTO 1)
    set(HAVE_ECC 1)

    set(CMAKE_REQUIRED_INCLUDES "${MBEDTLS_INCLUDE_DIR}/mbedtls")
    check_include_file(chacha20.h HAVE_MBEDTLS_CHACHA20_H)
    check_include_file(poly1305.h HAVE_MBEDTLS_POLY1305_H)
    if (WITH_BLOWFISH_CIPHER)
        check_include_file(blowfish.h HAVE_BLOWFISH)
    endif()

    unset(CMAKE_REQUIRED_INCLUDES)

endif (MBEDTLS_FOUND)

if (CMAKE_USE_PTHREADS_INIT)
    set(HAVE_PTHREAD 1)
endif (CMAKE_USE_PTHREADS_INIT)

if (UNIT_TESTING)
    if (CMOCKA_FOUND)
        set(CMAKE_REQUIRED_LIBRARIES ${CMOCKA_LIBRARIES})
        check_function_exists(cmocka_set_test_filter HAVE_CMOCKA_SET_TEST_FILTER)
        unset(CMAKE_REQUIRED_LIBRARIES)
    endif ()
endif ()

# OPTIONS
check_c_source_compiles("
__thread int tls;

int main(void) {
    return 0;
}" HAVE_GCC_THREAD_LOCAL_STORAGE)

check_c_source_compiles("
__declspec(thread) int tls;

int main(void) {
    return 0;
}" HAVE_MSC_THREAD_LOCAL_STORAGE)

###########################################################
# For detecting attributes we need to treat warnings as
# errors
if (UNIX OR MINGW)
    # Get warnings for attributes
    check_c_compiler_flag("-Wattributes" REQUIRED_FLAGS_WERROR)
    if (REQUIRED_FLAGS_WERROR)
        string(APPEND CMAKE_REQUIRED_FLAGS "-Wattributes ")
    endif()

    # Turn warnings into errors
    check_c_compiler_flag("-Werror" REQUIRED_FLAGS_WERROR)
    if (REQUIRED_FLAGS_WERROR)
        string(APPEND CMAKE_REQUIRED_FLAGS "-Werror ")
    endif()
endif ()

check_c_source_compiles("
void test_constructor_attribute(void) __attribute__ ((constructor));

void test_constructor_attribute(void)
{
    return;
}

int main(void) {
    return 0;
}" HAVE_CONSTRUCTOR_ATTRIBUTE)

check_c_source_compiles("
void test_destructor_attribute(void) __attribute__ ((destructor));

void test_destructor_attribute(void)
{
    return;
}

int main(void) {
    return 0;
}" HAVE_DESTRUCTOR_ATTRIBUTE)

check_c_source_compiles("
#define FALL_THROUGH __attribute__((fallthrough))

int main(void) {
    int i = 2;

    switch (i) {
    case 0:
        FALL_THROUGH;
    case 1:
        break;
    default:
        break;
    }

    return 0;
}" HAVE_FALLTHROUGH_ATTRIBUTE)

check_c_source_compiles("
#define WEAK __attribute__((weak))

WEAK int sum(int a, int b)
{
    return a + b;
}

int main(void)
{
    int i = sum(2, 2);

    (void)i;

    return 0;
}" HAVE_WEAK_ATTRIBUTE)

if (NOT WIN32)
    check_c_source_compiles("
    #define __unused __attribute__((unused))

    static int do_nothing(int i __unused)
    {
        return 0;
    }

    int main(void)
    {
        int i;

        i = do_nothing(5);
        if (i > 5) {
            return 1;
        }

        return 0;
    }" HAVE_UNUSED_ATTRIBUTE)
endif()

check_c_source_compiles("
#include <string.h>

int main(void)
{
    char buf[] = \"This is some content\";

    memset(buf, '\\\\0', sizeof(buf)); __asm__ volatile(\"\" : : \"g\"(&buf) : \"memory\");

    return 0;
}" HAVE_GCC_VOLATILE_MEMORY_PROTECTION)

check_c_source_compiles("
#include <stdio.h>
int main(void) {
    printf(\"%s\", __func__);
    return 0;
}" HAVE_COMPILER__FUNC__)

check_c_source_compiles("
#include <stdio.h>
int main(void) {
    printf(\"%s\", __FUNCTION__);
    return 0;
}" HAVE_COMPILER__FUNCTION__)

# This is only available with OpenBSD's gcc implementation */
if (OPENBSD)
check_c_source_compiles("
#define ARRAY_LEN 16
void test_attr(const unsigned char *k)
    __attribute__((__bounded__(__minbytes__, 2, 16)));

int main(void) {
    return 0;
}" HAVE_GCC_BOUNDED_ATTRIBUTE)
endif(OPENBSD)

# Stop treating warnings as errors
unset(CMAKE_REQUIRED_FLAGS)

# Check for version script support
file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "VERS_1 {
        global: sym;
};
VERS_2 {
        global: sym;
} VERS_1;
")

set(CMAKE_REQUIRED_FLAGS "-Wl,--version-script=\"${CMAKE_CURRENT_BINARY_DIR}/conftest.map\"")
check_c_source_compiles("int main(void) { return 0; }" HAVE_LD_VERSION_SCRIPT)
unset(CMAKE_REQUIRED_FLAGS)
file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")

if (WITH_DEBUG_CRYPTO)
  set(DEBUG_CRYPTO 1)
endif (WITH_DEBUG_CRYPTO)

if (WITH_DEBUG_PACKET)
  set(DEBUG_PACKET 1)
endif (WITH_DEBUG_PACKET)

if (WITH_DEBUG_CALLTRACE)
  set(DEBUG_CALLTRACE 1)
endif (WITH_DEBUG_CALLTRACE)

if (WITH_GSSAPI AND NOT GSSAPI_FOUND)
    set(WITH_GSSAPI 0)
endif (WITH_GSSAPI AND NOT GSSAPI_FOUND)

if (WITH_PKCS11_URI)
    if (WITH_GCRYPT)
        message(FATAL_ERROR "PKCS #11 is not supported for gcrypt.")
        set(WITH_PKCS11_URI 0)
    elseif (WITH_MBEDTLS)
        message(FATAL_ERROR "PKCS #11 is not supported for mbedcrypto")
        set(WITH_PKCS11_URI 0)
    elseif (OPENSSL_FOUND AND OPENSSL_VERSION VERSION_GREATER_EQUAL "3.0.0")
        find_library(PKCS11_PROVIDER
            NAMES
                pkcs11.so
            PATH_SUFFIXES
                ossl-modules
        )
        if (NOT PKCS11_PROVIDER)
            set(WITH_PKCS11_PROVIDER 0)
            message(WARNING "Could not find pkcs11 provider! Falling back to engines")
            message(WARNING "The support for engines is deprecated in OpenSSL and will be removed from libssh in the future releases.")
        endif (NOT PKCS11_PROVIDER)
    endif ()
endif()

# ENDIAN
if (NOT WIN32)
    test_big_endian(WORDS_BIGENDIAN)
endif (NOT WIN32)