#!/bin/sh
#
# build a PostgreSQL module based on PGXS for give list of supported major
# versions
#
# Author: Dimitri Fontaine <dfontaine@hi-media.com>

set -e

action="$1"
srcdir="$2"
target="$3"
opt="$4"

die() {
    echo "`basename $0`: error: $*" >&2
    exit 1
}

prepare_env() {
    version=$1
    vtarget=`echo $target | sed -e "s:%v:$version:g"`
    pgc="/usr/lib/postgresql/$version/bin/pg_config"
    [ -e "$pgc" ] || die "$pgc does not exit"
}

configure() {
    prepare_env $1
    confopts=`echo $opt | sed -e "s:%v:$version:g"`

    mkdir -p $vtarget
    ( echo "calling configure in $vtarget" &&
      cd $vtarget && $srcdir/configure $confopts PG_CONFIG="$pgc" )
}

build() {
    prepare_env $1
    cflags="`$pgc --cflags` `echo $opt | sed -e "s:%v:$version:g"`"

    mkdir -p $vtarget
    # if a Makefile was created by configure, use it, else the top level Makefile
    [ -f $vtarget/Makefile ] || makefile="-f $srcdir/Makefile"
    make -C $vtarget $makefile CFLAGS="$cflags" PG_CONFIG="$pgc" VPATH="$srcdir"
}

install() {
    prepare_env $1
    package=`echo $opt | sed -e "s:%v:$version:g"`

    mkdir -p $vtarget
    # if a Makefile was created by configure, use it, else the top level Makefile
    [ -f $vtarget/Makefile ] || makefile="-f $srcdir/Makefile"
    make -C $vtarget $makefile install DESTDIR="$srcdir/debian/$package" PG_CONFIG="$pgc" VPATH="$srcdir"
}

clean() {
    prepare_env $1

    # if a Makefile was created by configure, use it, else the top level Makefile
    [ -f $vtarget/Makefile ] || makefile="-f $srcdir/Makefile"
    [ -d $vtarget ] && make -C $vtarget clean $makefile PG_CONFIG="$pgc" VPATH="$srcdir"
    rm -rf $vtarget
}

versions() {
    [ -e /usr/share/postgresql-common/supported-versions ] ||
	die "/usr/share/postgresql-common/supported-versions not found"
    [ -e $srcdir/debian/pgversions ] || die "$srcdir/debian/pgversions not found"
    for v in `/usr/share/postgresql-common/supported-versions`
    do
	grep -q "^$v" $srcdir/debian/pgversions && echo $v
    done
}

[ "$srcdir" ] || die "syntax: pg_buildext <action> <srcdir> ..."
[ -d $srcdir ] || die "no such directory '$srcdir'"

for v in `versions`
do
    case "$action" in
	"supported-versions")
	    echo $v
	    ;;

	configure|build|install|clean)
	    [ "$target" ] || die "syntax: pg_buildext $action <srcdir> <target> ..."
	    # be verbose?
	    $action $v
	    ;;

	*)
	    die "unsupported $action."
	    ;;
    esac
done

exit 0

# POD follows here

=head1 NAME

pg_buildext - Build and install a PostgreSQL extension

=head1 SYNOPSIS

B<pg_buildext> I<action> I<srcdir> I<target> I<opts>

=head1 DESCRIPTION

B<pg_buildext> is a script that will build a PostgreSQL extension in a C<VPATH>
way. It supports the B<configure>, B<build>, B<install>, and B<clean> actions,
and will choose to build for the intersection of versions known in
C<debian/pgversions> (versions supported by the package) and in
C</usr/share/postgresql-common/supported-versions> (versions supported in this
release).

=head1 OPTIONS

=over 4

=item B<action>

One of B<configure>, B<build>, B<install>, or B<clean>.

=item B<srcdir>

Where to find the extension sources, including the C<debian> subdirectory.
(Usually C<$(CURDIR)>.)

=item B<target>

The target directory where to build the sources, it will get created for you
if it does not exist. If the B<target> contains a C<%v> sign, it will get
replaced by the specific version of PostgreSQL being built against.
(Usually C<build-%v>.)

=item B<opts>

C<%v> signs in B<opts> will get replaced as in B<target>.

=over 4

=item B<configure>

Options to pass to the I<configure> script. (Most PostgreSQL extensions do not
have a configure script.)

=item B<build>

Custom C<CFLAGS> options to use for the build.

=item B<install>

Package name to install for. Make will be called with DESTDIR="I<srcdir>/debian/I<package>".

=item B<clean>

B<clean> does not take extra options.

=back

=back

=head1 USAGE

As B<pg_buildext> invokes B<make> for the B<build>, B<install>, and B<clean>
actions, invocations from C<debian/rules> (which is a makefile) should be prefixed
with B<+> so the sub-makes can talk with the make jobserver.

=head1 EXAMPLE

  build-stamp:
	  +pg_buildext configure $(CURDIR) build-%v "--libdir=/usr/lib/postgresql/%v/lib --datadir=/usr/share/postgresql-%v-plsh"
	  +pg_buildext build $(CURDIR) build-%v

  install: build
	  +pg_buildext install $(CURDIR) build-%v postgresql-%v-plsh

  clean:
	  +pg_buildext clean $(CURDIR) build-%v


=head1 AUTHOR

Dimitri Fontaine L<E<lt>dim@tapoueh.orgE<gt>>, with extensions by
Christoph Berg L<E<lt>myon@debian.orgE<gt>>.