#!/bin/sh
# find rpm provides and requires for Haskell GHC libraries

[ $# -ne 2 ] && echo "Usage: `basename $0` [--provides|--requires] %{buildroot}%{ghclibdir}" && exit 1

set +x

MODE=$1
PKGBASEDIR=$2
PKGCONFDIR=$PKGBASEDIR/package.conf.d
GHC_VER=$(basename $PKGBASEDIR | sed -e s/ghc-//)

# for a ghc build use the new ghc-pkg
INPLACE_GHCPKG=$PKGBASEDIR/../../bin/ghc-pkg-$GHC_VER

if [ -x "$INPLACE_GHCPKG" ]; then
    case $GHC_VER in
        7.8.*)
            GHC_PKG="$PKGBASEDIR/bin/ghc-pkg --global-package-db=$PKGCONFDIR"
            ;;
        7.6.*)
            GHC_PKG="$PKGBASEDIR/ghc-pkg --global-package-db=$PKGCONFDIR"
            ;;
        *)
            GHC_PKG="$PKGBASEDIR/ghc-pkg --global-conf=$PKGCONFDIR"
            ;;
    esac
else
    GHC_PKG="/usr/bin/ghc-pkg-${GHC_VER}"
fi

case $MODE in
    --provides) FIELD=id ;;
    --requires) FIELD=depends ;;
    *) echo "`basename $0`: Need --provides or --requires" ; exit 1
esac

files=$(cat)

for i in $files; do
    META=""
    SELF=""
    case $i in
        */libHSrts.*) ;;
        */libHS*.so)
            META=ghc
	    PKGVER=$(echo $i | sed -e "s%$PKGBASEDIR/\([^/]\+\)/libHS.*%\1%")
            ;;
        */package.conf.d/*.conf)
            META=ghc-devel
	    PKGVER=$(echo $i | sed -e "s%$PKGCONFDIR/\(.\+\).conf%\1%")
	    if [ -f $PKGBASEDIR/$PKGVER/libHS$PKGVER-ghc${GHC_VER}.so ]; then
		SELF=ghc
	    fi
            ;;
    esac
    if [ "$META" -a -d "$PKGCONFDIR" ]; then
	HASHS=$(${GHC_PKG} -f $PKGCONFDIR field $PKGVER $FIELD | sed -e "s/^$FIELD: \+//")
	for i in $HASHS; do
	    case $i in
		*-*) echo "$META($i)" ;;
		*) ;;
	    esac
	done
	if [ "$MODE" = "--requires" -a "$SELF" ]; then
	    HASHS=$(${GHC_PKG} -f $PKGCONFDIR field $PKGVER id | sed -e "s/^id: \+//")
	    for i in $HASHS; do
		echo "$SELF($i)"
	    done
	fi
    elif [ "$MODE" = "--requires" ]; then
	if file $i | grep -q 'executable, .* dynamically linked'; then
	    BIN_DEPS=$(objdump -p $i | grep NEEDED | grep libHS | grep -v libHSrts | sed -e "s%^ *NEEDED *libHS\(.*\)-ghc${GHC_VER}.so%\1%")
	    if [ -d "$PKGCONFDIR" ]; then
		PACKAGE_CONF_OPT="--package-conf=$PKGCONFDIR"
	    fi
	    for p in ${BIN_DEPS}; do
		HASH=$(${GHC_PKG} --global $PACKAGE_CONF_OPT field $p id | sed -e "s/^id: \+//" | uniq)
		echo "ghc($HASH)"
	    done
	fi
    fi
done