#!/bin/sh
# Try and be like autotools configure, but without autotools

ARC4RANDOM=
CLOSEFROM=
GETLINE=
STRLCPY=

for x; do
	opt=${x%%=*}
	var=${x#*=}
	case "$opt" in
	--os|OS) OS=$var;;
	--with-cc|CC) CC=$var;;
	--debug) DEBUG=$var;;
	--disable-debug) DEBUG=no;;
	--enable-debug) DEBUG=yes;;
	--fork) FORK=$var;;
	--disable-fork) FORK=no;;
	--enable-fork) FORK=yes;;
	--prefix) PREFIX=$var;;
	--sysconfdir) SYSCONFDIR=$var;;
	--bindir|--sbindir) SBINDIR=$var;;
	--libexecdir) LIBEXECDIR=$var;;
	--statedir|--localstatedir) STATEDIR=$var;;
	--dbdir) DBDIR=$var;;
	--rundir) RUNDIR=$var;;
	--mandir) MANDIR=$var;;
	--with-ccopts|CFLAGS) CFLAGS=$var;;
	CPPFLAGS) CPPFLAGS=$var;;
	--build) BUILD=$var;;
	--host) HOST=$var;;
	--target) TARGET=$var;;
	--libdir) LIBDIR=$var;;
	--without-arc4random) ARC4RANDOM=no;;
	--without-closefrom) CLOSEFROM=no;;
	--without-getline) GETLINE=no;;
	--without-strlcpy) STRLCPY=no;;
	--datadir|--infodir) ;; # ignore autotools
	--help) echo "See the README file for available options"; exit 0;;
	*) echo "$0: WARNING: unknown option $opt" >&2;;
	esac
done

: ${SED:=sed}

: ${FORK:=yes}
: ${PREFIX:=}
: ${SYSCONFDIR:=$PREFIX/etc}
: ${SBINDIR:=$PREFIX/sbin}
: ${LIBDIR:=$PREFIX/lib}
: ${LIBEXECDIR:=$PREFIX/libexec}
: ${STATEDIR:=/var}
: ${DBDIR:=$STATEDIR/db}
: ${RUNDIR:=$STATEDIR/run}
: ${MANDIR:=${PREFIX:-/usr}/share/man}

_which()
{
	x="$(which "$1" 2>/dev/null)"
	if [ -n "$x" ]; then
		echo "$x"
		return 0
	fi
	for x in /sbin/"$1" /usr/sbin/"$1" \
		/usr/pkg/sbin/"$1" /usr/local/sbin/"$1"
	do
		if [ -e "$x" ]; then
			echo "$x"
			return 0
		fi
	done
	return 1
}

CONFIG_H=config.h
CONFIG_MK=config.mk

if [ -z "$BUILD" ]; then
	BUILD=`uname -m`-unknown-`uname -s | tr '[:upper:]' '[:lower:]'`
fi
if [ -z "$HOST" ]; then
	[ -z "$TARGET" ] && TARGET=$BUILD
	HOST=$TARGET
fi
if [ -z "$TARGET" ]; then
	[ -z "$HOST" ] && HOST=$BUILD
	TARGET=$HOST
fi

if [ -z "$OS" ]; then
	# Derive OS from cpu-manufacturer-os-kernel
	CPU=${TARGET%%-*}
	REST=${TARGET#*-}
	MANU=${REST%%-*}
	REST=${REST#*-}
	OS=${REST%%-*}
	REST=${REST#*-}
	KERNEL=${REST%%-*}
fi

echo "Configuring dhcpcd for ... $OS"
rm -f $CONFIG_H $CONFIG_MK
echo "# $OS" >$CONFIG_MK
echo "/* $OS */" >$CONFIG_H

for x in SYSCONFDIR SBINDIR LIBEXECDIR DBDIR RUNDIR; do
	eval v=\$$x
	# Make files look nice for import
	l=$((10 - ${#x}))
	unset t
	[ $l -gt 3 ] && t="	"
	echo "$x=$t	$v" >>$CONFIG_MK
	unset t
	[ $l -gt 2 ] && t="	"
	echo "#define $x$t	\"$v\"" >>$CONFIG_H
done
echo "LIBDIR=		$LIBDIR" >>$CONFIG_MK
echo "MANDIR=		$MANDIR" >>$CONFIG_MK

if [ -z "$CC" ]; then
	printf "Looking for compiler ... "
	for b in $TARGET- ""; do
		for cc in gcc pcc icc cc; do
			if type $b$cc >/dev/null 2>&1; then
				CC=$b$cc
				echo "$CC"
				break
			fi
		done
		[ -n "$CC" ] && break
	done
	if [ -z "$CC" ]; then
		echo
		echo "no suitable compiler found - aborting" >&2
		exit 1
	fi
else
	echo "Using compiler $CC"
fi
echo "CC=		$CC" >>$CONFIG_MK

if [ -n "$CFLAGS" ]; then
	echo "CFLAGS=		$CFLAGS" >>$CONFIG_MK
fi
if [ -n "$CPPLAGS" ]; then
	echo "CPPLAGS=		$CPPLAGS" >>$CONFIG_MK
fi

if [ -n "$DEBUG" -a "$DEBUG" != no -a "$DEBUG" != false ]; then
	echo "Enabling memory debugging"
	echo "CPPFLAGS+=	-DDEBUG_MEMORY" >>$CONFIG_MK
elif [ -z "$DEBUG" -a -d .git ]; then
	printf "Found git ... "
	DEBUG=yes
else
	DEBUG=no
fi
if [ "$DEBUG" != no -a "$DEBUG" != false ]; then
	echo "Adding debugging CFLAGS"
	cat <<EOF >>$CONFIG_MK
CFLAGS+=	-Wall -Wextra -Wimplicit -Wshadow -Wformat=2
CFLAGS+=	-Wmissing-prototypes -Wmissing-declarations
CFLAGS+=	-Wmissing-noreturn -Wmissing-format-attribute
CFLAGS+=	-Wredundant-decls  -Wnested-externs
CFLAGS+=	-Winline -Wwrite-strings -Wcast-align -Wcast-qual
CFLAGS+=	-Wpointer-arith
CFLAGS+=	-Wdeclaration-after-statement -Wsequence-point
CFLAGS+=	-fno-common
EOF
fi

if [ -n "$FORK" -a "$FORK" != yes -a "$FORK" != true ]; then
	echo "There is no fork"
	echo "CPPFLAGS+=	-DTHERE_IS_NO_FORK" >>$CONFIG_MK
fi

case "$OS" in
linux)
	echo "CPPFLAGS+=	-D_BSD_SOURCE -D_XOPEN_SOURCE=600" >>$CONFIG_MK
	echo "SRCS+=		if-linux.c if-linux-wireless.c lpf.c" >>$CONFIG_MK
	echo "LDADD+=		-lrt" >>$CONFIG_MK
	;;
*)
	echo "SRCS+=		bpf.c if-bsd.c" >>$CONFIG_MK
	;;
esac

# Even if we build for $PREFIX, the clueless user might move us to /
LDELF=/libexec/ld.elf_so
if [ -e "$LDELF" ]; then
	echo "Linking against $LDELF"
	echo "LDFLAGS+=	-Wl,-dynamic-linker=$LDELF" >>$CONFIG_MK
fi

# Add CPPFLAGS and CFLAGS to CC for testing features
XCC="$CC `$SED -n -e 's/CPPLAGS+=*\(.*\)/\1/p' $CONFIG_MK`"
XCC="$XCC `$SED -n -e 's/CFLAGS+=*\(.*\)/\1/p' $CONFIG_MK`"

abort=false
# We require the libc to support non standard functions, like getifaddrs
printf "Testing for getifaddrs ... "
cat <<EOF >_getifaddrs.c
#include <sys/types.h>
#include <ifaddrs.h>
int main(void) {
	struct ifaddrs *ifap;
	return getifaddrs(&ifap);
}
EOF
if $XCC _getifaddrs.c -o _getifaddrs 2>/dev/null; then
	echo "yes"
else
	echo "no"
	echo "libc support for getifaddrs is required - aborting" >&2
	abort=true
fi
rm -f _getifaddrs.c _getifaddrs
$abort && exit 1

if [ -z "$ARC4RANDOM" ]; then
	printf "Testing for arc4random ... "
	cat <<EOF >_arc4random.c
#include <stdlib.h>
int main(void) {
	uint32_t r = arc4random();
	return 0;
}
EOF
	if $XCC _arc4random.c -o _arc4random 2>/dev/null; then
		ARC4RANDOM=yes
	else
		ARC4RANDOM=no
	fi
	echo "$ARC4RANDOM"
	rm -f _arc4random.c _arc4random
fi
if [ "$ARC4RANDOM" = no ]; then
	echo "COMPAT_SRCS+=	compat/arc4random.c" >>$CONFIG_MK
	echo "#include \"compat/arc4random.h\"" >>$CONFIG_H
fi

if [ -z "$CLOSEFROM" ]; then
	printf "Testing for closefrom ... "
	cat <<EOF >_closefrom.c
#include <unistd.h>
int main(void) {
	int r = closefrom(3);
	return 0;
}
EOF
	if $XCC _closefrom.c -o _closefrom 2>/dev/null; then
		CLOSEFROM=yes
	else
		CLOSEFROM=no
	fi
	echo "$CLOSEFROM"
	rm -f _closefrom.c _closefrom
fi
if [ "$CLOSEFROM" = no ]; then
	echo "COMPAT_SRCS+=	compat/closefrom.c" >>$CONFIG_MK
	echo "#include \"compat/closefrom.h\"" >>$CONFIG_H
fi

if [ -z "$GETLINE" ]; then
	printf "Testing for getline ... "
	cat <<EOF >_getline.c
#define _GNU_SOURCE
#include <stdio.h>
int main(void) {
	char *buf = NULL;
	size_t n = 0;
	getline(&buf, &n, stdin);
	return 0;
}
EOF
	if $XCC _getline.c -o _getline 2>/dev/null; then
		GETLINE=yes
	else
		GETLINE=no
	fi
	echo "$GETLINE"
	rm -f _getline.c _getline
fi
if [ "$GETLINE" = no ]; then
	echo "COMPAT_SRCS+=	compat/getline.c" >>$CONFIG_MK
	echo "#include \"compat/getline.h\"" >>$CONFIG_H
fi

if [ -z "$STRLCPY" ]; then
	printf "Testing for strlcpy ... "
	cat <<EOF >_strlcpy.c
#include <string.h>
int main(void) {
	const char s1[] = "foo";
	char s2[10];
	strlcpy(s2, s1, sizeof(s2));
	return 0;
}
EOF
	if $XCC _strlcpy.c -o _strlcpy 2>/dev/null; then
		STRLCPY=yes
	else
		STRLCPY=no
	fi
	echo "$STRLCPY"
	rm -f _strlcpy.c _strlcpy
fi
if [ "$STRLCPY" = no ]; then
	echo "COMPAT_SRCS+=	compat/strlcpy.c" >>$CONFIG_MK
	echo "#include \"compat/strlcpy.h\"" >>$CONFIG_H
fi

echo
echo "   SYSCONFDIR =		$SYSCONFDIR"
echo "   SBINDIR =		$SBINDIR"
echo "   LIBDIR =		$LIBDIR"
echo "   LIBEXECDIR =		$LIBEXECDIR"
echo "   DBDIR =		$DBDIR"
echo "   RUNDIR =		$RUNDIR"
echo "   MANDIR =		$MANDIR"
echo