#!/bin/sh

c_exports="program version target cflags"

make_exports="program version target \
              prefix libdir includedir mandir \
              cflags ldflags ldadd libdepends \
              sources objs deps mans headers extra_dist subdirs \
              abi_major abi_minor abi_version \
              cc cpp ld ln ar install diff"

required_headers=
optional_headers=

pre_configure_hook() {
    return
}

post_configure_hook() {
    return
}

export_to_make() {
  for id in $*
  do

    # Prepend $DESTDIR to installation directories
    case "$id" in
        prefix|libdir|includedir|mandir)  
        eval "$id=\"\\\$\\\$DESTDIR\$$id\""
    esac

    uc_id=`echo $id | $tr '[:lower:]' '[:upper:]'`;
    eval "echo \"$uc_id=\"\$$id\"\" >> config.mk"
  done
}

export_to_c() {
  for id in $*
  do
    uc_id=`echo $id | $tr '[:lower:]' '[:upper:]'`;
    eval "echo \"#define $uc_id \\\"\$$id\\\"\" >> config.h"
  done
}

finalize() {
  uc_id=`echo \"$1\" | $tr '[:lower:]' '[:upper:]'`;
  eval "if [ \"\$$1\" = \"\" ] ; then $1=\"$2\" ; fi"
}

process_argv() {
    for arg in $*
    do
        id=`echo "$arg" | sed 's/=.*//; s/^--//;'`
        val=`echo "$arg" | sed 's/^.*=//'`
        if [ "$val" = "" ] ; then val=1 ; fi
        eval "$id=\"$val\"" 
    done
}

process_env() {
    test -n "$CC" && cc="$CC"
    test -n "$CPP" && cpp="$CPP"
    test -n "$CPPFLAGS" && cppflags="$CPPFLAGS"
    test -n "$CFLAGS" && cflags="$CFLAGS"
    test -n "$LD" && ld="$LD"
    test -n "$LN" && ld="$LN"
    test -n "$LDFLAGS" && ldflags="$LDFLAGS"
    test -n "$AR" && ar="$AR"
}
 
check_header() {	 
   sym=`echo "have_$1" | sed 's,[./],_,g'`	 
   uc_sym=`echo "$sym" | $tr '[:lower:]' '[:upper:]'`;
   path=$1

   printf "checking for $path.. "
   if [ -f "/usr/include/$path" ] ; then
     echo "yes"
     echo "#define $uc_sym 1" >> config.h
     eval "$sym=yes"
     return 0
   else  
     echo "no"
     echo "#undef $uc_sym" >> config.h
     eval "$sym=no"
     return 1
   fi
}

check_headers() {	 
   for header in $*
   do
       check_header "$header"
   done
}

check_symbol() {
    header=$1
    symbol=$2

    uc_symbol=`echo "HAVE_$symbol" | $tr '[:lower:]' '[:upper:]' | sed 's,[./],_,g'`
    lc_symbol=`echo "have_$symbol" | $tr '[:upper:]' '[:lower:]' | sed 's,[./],_,g'`

    if [ -f "$header" ] ; then
        path="$header"
    elif [ -f "/usr/include/$header" ] ; then
        path="/usr/include/$header"
    else
        echo "*** ERROR: Cannot find <$header>"
        exit 1
    fi
     
    printf "checking $header for $symbol.. "    
    if [ "`grep $symbol $path`" != "" ] ; then
     eval "$lc_symbol=yes"
     echo "#define $uc_symbol 1" >> config.h
     echo "yes"
     return 0
    else
     eval "$lc_symbol=no"
     echo "no"
     echo "#undef $uc_symbol" >> config.h
     return 1
    fi
}

check_install() {
    printf "checking for a BSD-compatible install.. "
    if [ "`uname -s`" = "SunOS" ] ; then
        default_install=/usr/ucb/install
    else
        default_install=/usr/bin/install
    fi
    finalize install "$default_install"
    echo "$install"
}

check_target() {
    printf "checking operating system type.. "
    default_target=`uname -s | $tr '[:upper:]' '[:lower:]'`
    if [ "$default_target" = "sunos" ] ; then
       default_target="solaris"
    fi
    finalize target "$default_target"
    echo "$target"
}

check_compiler() {
    printf "checking for a C compiler.. "
    if [ "`uname -s`" = "SunOS" ] ; then
       default_cc="/usr/sfw/bin/gcc"
    else
       default_cc="/usr/bin/cc"
    fi
    finalize cc "$default_cc"
    echo "$cc"
}

check_linker() {
    printf "checking for a suitable linker.. "

    # Workaround for "hidden symbol <foo> is referenced by DSO" linker error
    # seen when compiling libdispatch.
    # Appears to be a problem with GCC 4.0 and binutils
    #
    default_ld="$cc"
    ldflags="-shared -o $program.so.$abi_major.$abi_minor $ldflags"

    # FIXME: port to solaris
    if [ "$target" = "linux" ] ; then
    ldflags="$ldflags -Wl,-export-dynamic -Wl,-soname,$program.so.$abi_major"
    fi 

    if [ "$target" = "solaris" ] ; then
    ldflags="$ldflags"
    fi

    finalize ld "$default_ld"
    echo "$ld"
}

check_archiver() {
    printf "checking for a suitable archiver.. "
    if [ "`uname -s`" = "SunOS" ] ; then
       default_ar="/usr/sfw/bin/gar"
    else
       default_ar="/usr/bin/ar"
    fi
    finalize ar "$default_ar"
    echo "$ar"
}

err() {
    echo "*** ERROR *** $*"
    rm -f config.mk $program.pc config.h
    exit 1
}

check_diff() {
    # TODO: Support non-GNU diff syntax
    # TODO: Search for the command
    printf "checking for a suitable diff(1) command.. "
    finalize diff "diff -ruN -dEbwBp -x .svn -x .o -x config.h -x config.mk"
    echo "found"
}

subst_vars() {
  outfile=$1

  if [ ! -f "${outfile}.in" ] ; then
      return
  fi

  echo "Creating $outfile"
  rm -f $outfile
  sed -e "
       s,@@PROGRAM@@,$program,g;
       s,@@VERSION@@,$version,g;
       s,@@PREFIX@@,$prefix,g;
       s,@@LIBDIR@@,$libdir,g;
       s,@@INCLUDEDIR@@,$includedir,g;
       s,@@MANDIR@@,$mandir,g;
       s,@@LIBDEPENDS@@,$libdepends,g;
       s,@@PKG_SUMMARY@@,$pkg_summary,g;
       s,@@PKG_DESCRIPTION@@,$pkg_description,g;
       s,@@LICENSE@@,$license,g;
       s,@@AUTHOR@@,$author,g;
       " < ${outfile}.in > $outfile
  chmod 400 $outfile
}

#######################################################################
#
#                           MAIN()
#
#######################################################################

# Workaround for Solaris "Bad string" issue when LOCALE is undefined
tr="/usr/bin/tr"
test -f /usr/xpg4/bin/tr && tr="/usr/xpg4/bin/tr"

. ./config.inc

# Initialize the output files
#
for output_file in config.mk $program.pc
do
   rm -f $output_file
   echo "# AUTOMATICALLY GENERATED -- DO NOT EDIT" > $output_file
done
rm -f config.h
echo "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */" > config.h

process_argv "$*"
process_env

check_target
check_compiler
check_linker
check_archiver
check_install
check_diff

finalize program    "$program"
finalize version    "$version"
finalize abi_major  "$abi_major"
finalize abi_minor  "$abi_minor"
finalize abi_version "$abi_major.$abi_minor"
finalize prefix     "/usr/local"
finalize libdir     "${prefix}/lib"
finalize includedir "${prefix}/include"
finalize mandir     "${prefix}/share/man"
finalize cflags     "$cflags"
finalize libdepends "$libdepends"
finalize ldadd      ""
finalize ldflags    ""
finalize deps       ""
finalize ln         "`which ln`"

pre_configure_hook

for header in $required_headers
do
  check_header "$header" || err "$header is required, but cannot be found."
done
check_headers $optional_headers

post_configure_hook

objs="`echo \"$sources\" | sed 's/\.c/\.o/g'`"

subst_vars "$program.pc"
subst_vars "$program.la"
subst_vars "rpm.spec"

echo "Creating config.h"
export_to_c $c_exports

echo "Creating config.mk"
export_to_make "$make_exports"