AC_INIT([utun], [2.0.0], [https://github.com/anomalyco/utun3/issues])
AC_CONFIG_SRCDIR([src/utun.c])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([m4])

# Required programs
AC_PROG_CC
AC_PROG_CC_C99
AM_INIT_AUTOMAKE([foreign subdir-objects -Wall -Werror])

# Checks for programs
AC_PROG_INSTALL
AC_PROG_MAKE_SET

# Checks for libraries
AC_CHECK_LIB([crypto], [SHA256_Init], [], [AC_MSG_ERROR([OpenSSL crypto library required])])

# Checks for header files
AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netinet/in.h stdlib.h string.h sys/ioctl.h sys/socket.h unistd.h])

# Checks for typedefs, structures, and compiler characteristics
AC_TYPE_SIZE_T
AC_TYPE_SSIZE_T
AC_TYPE_UINT16_T
AC_TYPE_UINT32_T
AC_TYPE_UINT64_T
AC_TYPE_UINT8_T
AC_C_INLINE

# Checks for library functions
AC_FUNC_MALLOC
AC_CHECK_FUNCS([gettimeofday memset socket strchr strdup strerror strstr])

# Check for TUN/TAP support
AC_MSG_CHECKING([for TUN/TAP support])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <linux/if_tun.h>
]], [[
int fd = open("/dev/net/tun", O_RDWR);
]])], [
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_TUN_TAP], [1], [Define if TUN/TAP is available])
], [
  AC_MSG_RESULT([no])
])

# Output files
AC_CONFIG_FILES([
  Makefile
  src/Makefile
  tests/Makefile
  u_async/Makefile
])

AC_OUTPUT

# Summary
echo "
Configuration summary:
----------------------
  Prefix:       ${prefix}
  Compiler:     ${CC}
  CFLAGS:       ${CFLAGS}
  
  Features:
    TUN/TAP:    ${have_tun_tap}
"