# -*-shell-script-*-
#
# (c) Sean Seefried 2005
#
# A library of useful functions for configure scripts
#


#--------------------------------------------------------------------
# Function "findprogram": find a program in the path
#--------------------------------------------------------------------
findprogram () {
  if test -f $1; then return 0; fi
  saveIFS="$IFS"
  IFS=':'
  for dir in $PATH; do
    if test -z "$dir"; then dir=.; fi
    if test -f $dir/$1; then 
      IFS="$saveIFS"
      return 0
    fi
  done
  IFS="$saveIFS"
  return 1
}


#--------------------------------------------------------------------
# Parse command-line arguments
#--------------------------------------------------------------------
process_args () 
{
  arg=""
  while : ; do
    # put optional argument in the $arg variable
    case "$1" in
     -*=*) arg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` 
	   arg=`eval echo $arg`;;  # expand ~
     *)    arg="";;
    esac

    # match on the arguments
    case "$1" in
      "") break;;
      -?|--help)
	  echo "usage:"
	  echo " ./configure [options]"
	  echo ""
	  echo "options: [defaults in brackets]"
	  echo " --help                      show this information"
	  echo " --with-hc=<program>         the haskell compiler [$hc]"
	  echo " --with-hc-pkg=<program>     package compiler [$hcpkg]"

	  echo "install options:"
	  echo " --prefix=<dir>              install directory [$prefix]"
	  exit 1;;

      -with-hc=*|--with-hc=*)
	  hc="$arg";;
      -with-hc-pkg=*|--with-hc-pkg=*)
	  hc_pkg="$arg";;
    esac

    # process next argument
    shift
  done
  return 0;
}

echoc()
{
 echo configure: "$@"
}

#----------------------------------------------------------------------
# Get the version of the haskell compiler
#----------------------------------------------------------------------

get_version()
{
  echo "`$hc --version | sed -e 's|[^0-9.]*\([0-9.][0-9.]*\)|\1|'`"
}

#
# Converts a version number of form MAJ.MIN.PATCHLEVEL to an integer
#


#----------------------------------------------------------------------
# Get the version of the haskell compiler as an integer
#----------------------------------------------------------------------

get_version_int()
{
  version=`get_version`
  MAJ="`echo $version | sed 's|\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.*\([0-9][0-9]*\)*|\1|'`"
  MIN="`echo $version | sed 's|\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.*\([0-9][0-9]*\)*|\2|'`"
  PATCH="`echo $version | sed 's|\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.*\([0-9][0-9]*\)*|\3|'`"
  if test "$PATCH" = "" ; then
    PATCH=0
  fi
  echo `expr $MAJ \* 10000 + $MIN \* 100 + $PATCH`
}

#----------------------------------------------------------------------
# Get the OS type
#----------------------------------------------------------------------

get_OS()
{
  uname -s
}


#----------------------------------------------------------------------
# Substitute a value in a file (a la AC_SUBST)
#
# The first (n-1) arguments given to this command are variables to be
# substituted. The last argument is the file in which to
# substitute. Call this FILE. The command will look for a file called FILE.in
# and produce a substituted file called FILE.
# ----------------------------------------------------------------------
subst()
{
  local SED_CMD
  local n

  n=$(($#-1))
  FILE=${!#}
  while test $n -gt 0; do
    echoc Substituting @$1@ in $FILE
    SED_CMD="$SED_CMD -e 's|@$1@|${!1}|g'"
    shift
    n=$((n-1))
  done
  if test -f $FILE.in ; then
    SED_CMD="$SED_CMD $FILE.in"
    echo "$SED_CMD" | xargs sed > $FILE
  fi

}

#----------------------------------------------------------------------
# Gets a value from .setup-config file
#
# $1 is the name of the field the value is attached to e.g. buildDir
# $2 is the .setup-config file
#----------------------------------------------------------------------
get_config_value()
{
FIELD=$1
SETUP_CONFIG=$2
cat $SETUP_CONFIG | sed "s|.*$FIELD = \"\([^\"]*\)\".*|\1|"
}

#----------------------------------------------------------------------
# Gets a value from a Cabal file
#
# $1 is the name of the field the value is attached to e.g. name,
# version, executable
#
# $2 is the .cabal file
#----------------------------------------------------------------------
get_cabal_value()
{
  FIELD=$1
  CABAL=$2
  cat $CABAL | grep -i "$1:" | sed 's|.*:[[:space:]]*\([^[:space:]]*\)|\1|'
}

#----------------------------------------------------------------------
# Gets the installation directory from  a Cabal .setup-config file and
# a Cabal .cabal file
# $1 is the path to .setup-config and $2 is the path to the .cabal file
#----------------------------------------------------------------------
get_install_dir()
{
SETUP_CONFIG=$1
CABAL=$2
prefix="`cat $SETUP_CONFIG | sed 's|.*prefix = \"\([^\"]*\)\".*|\1|'`"
name=`get_cabal_value name $CABAL`
ver=`get_cabal_value version $CABAL`
echo $prefix/lib/$name-$ver
}

#
# Defaults
#

prefix=/usr/local
hc="ghc"
hcpkg="ghc-pkg"