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

# Ensure that we do not inherit these from env
DEBUG=

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;;
	--prefix) prefix=$var;;
	--sysconfdir) SYSCONFDIR=$var;;
	--bindir|--sbindir) SBINDIR=$var;;
	--libexecdir) LIBEXECDIR=$var;;
	--statedir|--localstatedir) STATEDIR=$var;;
	--rundir) RUNDIR=$var;;
	--mandir) MANDIR=$var;;
	--with-ccopts|CFLAGS) CFLAGS=$var;;
	CPPFLAGS) CPPFLAGS=$var;;
	--build) BUILD=$var;;
	--host) HOST=$var;;
	--target) TARGET=$var;;
	--includedir) eval INCLUDEDIR="$INCLUDEDIR${INCLUDEDIR:+ }$var";;
	--libdir) LIBDIR=$var;;
	--datadir|--infodir) ;; # ignore autotools
	--disable-maintainer-mode|--disable-dependency-tracking) ;;
	--help) echo "See the README file for available options"; exit 0;;
	*) echo "$0: WARNING: unknown option $opt" >&2;;
	esac
done

: ${SED:=sed}

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

eval SYSCONFDIR="$SYSCONFDIR"
eval LIBDIR="$LIBDIR"
eval LIBEXECDIR="$LIBEXECDIR"
eval STATEDIR="$STATEDIR"
eval DBDIR="$DBDIR"
eval RUNDIR="$RUNDIR"
eval MANDIR="$MANDIR"

_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 "$BUILD" ]; then
	# autoconf target triplet: cpu-vendor-os
	BUILD=$(uname -m)-unknown-$(uname -s | tr '[:upper:]' '[:lower:]')
fi
: ${HOST:=$BUILD}

if [ -z "$OS" ]; then
	echo "Deriving operating system from ... $HOST"
	# Derive OS from cpu-vendor-[kernel-]os
	CPU=${HOST%%-*}
	REST=${HOST#*-}
	if [ "$CPU" != "$REST" ]; then
		VENDOR=${REST%%-*}
		REST=${REST#*-}
		if [ "$VENDOR" != "$REST" ]; then
			# Use kernel if given, otherwise os
			OS=${REST%%-*}
		else
			# 2 tupple
			OS=$VENDOR
			VENDOR=
		fi
	fi

        # Work with cpu-kernel-os, ie Debian
	case "$VENDOR" in
	linux*|kfreebsd*) OS=$VENDOR; VENDOR= ;;
	esac
	# Special case
	case "$OS" in
	gnu*) OS=hurd;; # No HURD support as yet
	esac
fi

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

# Always obey CC.
# However, if CC is not specified and we are given GNU style
# --host or --build targets the expectation is we try and match that
# to a compiler.
if [ -n "$CC" ]; then
	HOSTCC=
else
	CC=cc
	_COMPILERS="cc clang gcc pcc icc"
fi
if [ -n "$HOSTCC" ]; then
	for _CC in $_COMPILERS; do
		_CC=$(_which "$HOSTCC$_CC")
		if [ -x "$_CC" ]; then
			CC=$_CC
			break
		fi
	done
fi
if ! type "$CC" >/dev/null 2>&1; then
	for _CC in $_COMPILERS; do
		_CC=$(_which "$_CC")
		if [ -x "$_CC" ]; then
			CC=$_CC
			break
		fi
	done
fi

echo "Using compiler .. $CC"
if ! type "$CC" >/dev/null 2>&1; then
	echo "$CC is not an executable"
	exit 1
fi
[ "$CC" != cc ] && echo "CC=	$CC" >>$CONFIG_MK
$CC --version | $SED -e '1!d'

for x in PREFIX SYSCONFDIR LIBEXECDIR 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

if [ -n "$CFLAGS" ]; then
	echo "CFLAGS=		$CFLAGS" >>$CONFIG_MK
fi
if [ -n "$CPPLAGS" ]; then
	echo "CPPLAGS=		$CPPLAGS" >>$CONFIG_MK
fi
for x in $INCLUDEDIR; do
	echo "CPPFLAGS+=	-I$x" >>$CONFIG_MK
done

if [ -z "$DEBUG" -a -f .fslckout ]; then
	printf "Found fossil checkout ... "
	DEBUG=yes
else
	DEBUG=no
fi
if [ "$DEBUG" != no -a "$DEBUG" != false ]; then
	echo "Adding debugging CFLAGS"
	cat <<EOF >>$CONFIG_MK
CFLAGS+=	-g -Wall -Wextra -Wshadow -Wformat=2
CFLAGS+=	-Wmissing-prototypes -Wmissing-declarations
CFLAGS+=	-Wmissing-noreturn -Wmissing-format-attribute
CFLAGS+=	-Wnested-externs
CFLAGS+=	-Winline -Wwrite-strings -Wcast-align -Wcast-qual
CFLAGS+=	-Wpointer-arith -Wstrict-overflow
CFLAGS+=	-Wdeclaration-after-statement
CFLAGS+=	-Wconversion
EOF
	case "$OS" in
	mirbsd*|openbsd*);; # OpenBSD has many redundant decs in system headers
	*)		echo "CFLAGS+=	-Wredundant-decls" >>$CONFIG_MK;;
	esac
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
printf "Testing for clock_gettime ... "
cat <<EOF >_clock_gettime.c
#include <time.h>
int main(void) {
	struct timespec ts;
	return clock_gettime(CLOCK_MONOTONIC, &ts);
}
EOF
if $XCC _clock_gettime.c -o _clock_gettime 2>/dev/null; then
	echo "yes"
elif $XCC _clock_gettime.c -lrt -o _clock_gettime 2>/dev/null; then
	echo "yes (-lrt)"
	echo "LDADD+=		-lrt" >>$CONFIG_MK
else
	echo "no"
	echo "libc support for clock_getttime is required - aborting" >&2
	abort=true
fi
rm -f _clock_gettime.c _clock_gettime
$abort && exit 1

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 [ "$STRLCPY" = no ]; then
	echo "#define strlcpy(dst, src, n) snprintf(dst, n, \"%s\", src)" \
	>>$CONFIG_H
fi

# Get DBus CFLAGS
DBUS_CFLAGS=$(pkg-config --cflags dbus-1) || exit 1
DBUS_LIBS=$(pkg-config --libs dbus-1) || exit 1
echo "DBus CFLAGS=$DBUS_CFLAGS"
echo "DBus LIBS=$DBUS_LIBS"
echo "CPPFLAGS+=	$DBUS_CFLAGS" >>config.mk
echo "LDADD+=		$DBUS_LIBS" >>config.mk

echo
echo "   SYSCONFDIR =		$SYSCONFDIR"
echo "   LIBEXECDIR =		$LIBEXECDIR"
echo "   DBDIR =		$DBDIR"
echo "   RUNDIR =		$RUNDIR"
echo