#! /bin/bash
###
### Build script for Debian packages
###
### (c) 2008 Mark Wooding
###

###----- Licensing notice ---------------------------------------------------
###
### This program is free software; you can redistribute it and/or modify
### it under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2 of the License, or
### (at your option) any later version.
###
### This program is distributed in the hope that it will be useful,
### but WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with this program; if not, write to the Free Software Foundation,
### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

###--------------------------------------------------------------------------
### Conventions for build systems.
###
### This script is designed to work with a variety of `make'-based build
### systems, but there are a number of conventions which must be followed if
### this is going to work properly.
###
###   * There must be a `configure.ac', `configure.in', or `.links' file, or
###	a `.git' directory in the project top-level, so that we can find it.
###
###   * The following `make' variables must be assigned in the top-level
###	Makefile, after `mdw-build' has constructed it.
###
###	distdir		The name of the top-level project directory in the
###			source distribution, and the base name for
###			distribution archives; should be of the form
###			`PROJECT-VERSION'.
###
###	The following `make' targets must be available in the top-level
###	Makefile.
###
###	dist		Write to $(distdir).tar.gz a source distribution of
###			the package.
###
###	distcheck	As for `dist', but also build and test the project.
###
###  * The source distribution constructed by `make dist' must contain a file
###	$(distdir)/RELEASE containing the release name.  This isn't currently
###	tested, but it might be later.

set -e

###--------------------------------------------------------------------------
### Parse options.

prog=${0##*/}

usage () {
  cat <<EOF
Usage: $prog [-vr] BUILDOPT

Build options:

  [no]checkout[=REV]
  [no]release
  [no]setup[=RUNE]
  [no]distcheck
  [no]debian
  [no]upload
  [no]clean
  [no]vpath
  [no]native
EOF
}

## Parse simple options.
verbose=no
while getopts "hvr" opt; do
  case "$opt" in
    h) usage; exit 0 ;;
    v) verbose=yes ;;
    *) exit 1 ;;
  esac
done
shift $((OPTIND - 1))

## Parse the build options.
checkout=yes
checkoutrev=HEAD
build=test
setup=yes
setupcmd=mdw-setup
distcheck=yes
debian=yes
upload=yes
clean=yes
vpath=yes
native=yes
for opt; do
  case "$opt" in
    checkout)	checkout=yes checkoutrev=HEAD ;;
    checkout=*) checkout=yes checkoutrev=${opt#*=} ;;
    release)	build=release ;;
    norelease)	build=test ;;
    setup)	setup=yes setupcmd=mdw-setup ;;
    setup=*)	setup=yes setupcmd=${opt#*=} ;;

    distcheck | debian | upload | clean | vpath | native)
      eval "$opt=yes"
      ;;
    nocheckout | nosetup | nodistcheck | nodebian | \
    noupload | noclean | novpath | nonative)
      eval "${opt#no}=no"
      ;;
    *)
      usage >&2
      exit 1
      ;;
  esac
done

## Parse DEB_BUILD_OPTIONS.
jobs=1
set -- $DEB_BUILD_OPTIONS
for opt; do
  case "$opt" in
    parallel=*) jobs=${opt#*=} ;;
  esac
done

makeopts=""
case $jobs in 1) ;; *) makeopts="$makeopts -j$jobs" ;; esac

###--------------------------------------------------------------------------
### Utility functions.

exec 3>&2 4>/dev/null 5>&2

notify () {
  colour=$1 message=$2
  echo $message >&4
  echo "$(tput bold; tput setaf $colour)$message$(tput sgr0; tput op)" >&5
}

fail () {
  notify 1 "!!! $*"
  exit 1
}

warn () {
  case $build in
    release) fail "$*" ;;
    *) notify 5 "??? $*" ;;
  esac
}

info () {
  notify 6 "--- $*"
}

assign () {
  info "$1 = $2"
  eval "$1=$2"
}

runx () {
  notify 2 "+++ $*"
  "$@" 2>&3 || fail "$1: exit $?"
}

run () { runx "$@" >&3; }

yesno () {
  echo -n "(test $*)" >&4
  if "$@" >&4 2>&4; then
    echo "(yes)" >&4
    echo yes
  else
    echo "(no)" >&4
    echo no
  fi
}

###--------------------------------------------------------------------------
### Do the building.

## Find the top-level package directory.
while [ ! -f configure.ac -a ! -f configure.in -a \
	! -f .links -a ! -d .git ]; do
  case "$(pwd)" in
    /)
      fail "couldn't find top-level directory"
      ;;
  esac
  cd ..
done
assign srcpath $(pwd)

## Build any necessary qualifiers.
qual= sep=.
case ${SBOX_SESSION_DIR+t},${DEB_BUILD_ARCH+t} in
  t,t) qual=$qual$sep$DEB_BUILD_ARCH; sep=- ;;
  t,*) fail "unknown build arch" ;;
esac

## Construct the output directory.
assign releasepath $srcpath/dist-$build$qual
chmod -R +w $releasepath 2>/dev/null || :
rm -rf $releasepath 2>/dev/null || :
mkdir $releasepath
case $verbose in
  no)
    exec 4>$releasepath/mdw-build.log 3>&4 ||
      fail "Failed to create log."
    ;;
esac

## Do we have a Git repository?
case "$checkout,$setup,$(yesno [ -d $srcpath/.git ])" in
  yes,no,*)
    fail "Inconsistent options: can't check out without setup."
    ;;
  yes,yes,no)
    info "No Git repository found."
    checkout=no gitver=none
    ;;
  yes,yes,yes)
    cd $srcpath
    [ "$(git ls-files -m)" = "" ] ||
      warn "working tree has uncommitted changes"
    ;;
esac

## Is there Debian build equipment?
case "$debian,$(yesno [ -d $srcpath/debian ])" in
  yes,no)
    info "No debian directory found."
    debian=no debver=none
    ;;
  no,*)
    debver=none
    ;;
  yes,yes)
    debver=$(dpkg-parsechangelog | sed -n 's/^Version: //p' | tr \~ -)
    debsrc=$(dpkg-parsechangelog | sed -n 's/^Source: //p')
    debname=$(git config user.name) debemail=$(git config user.email)
    ;;
esac

## Maybe check out a copy of the source.
case "$checkout" in
  yes)
    cd $releasepath
    run git clone -sn $srcpath/.git _source
    assign srcpath $releasepath/_source
    cd $srcpath
    run git checkout -b mdw-build $checkoutrev
    gitver=$(git describe --abbrev=4)
    ;;
esac

## Check the version number.
hack_dch_p=no
case "$gitver,$debver" in
  none,* | *,none)
    ;;
  *)
    if [ "$gitver" != "$debver" ]; then
      warn "Git version $gitver doesn't match Debian version $debver"
      hack_dch=yes
    fi
    ;;
esac

## Maybe refresh the build machinery.
case "$setup" in
  yes)
    run $setupcmd
    ;;
esac

## Initialize the build directory.
case "$vpath,$(yesno [ -e $srcpath/configure ])" in
  yes,yes)
    assign buildpath $releasepath/_build
    mkdir $buildpath
    cd $buildpath
    run $srcpath/configure
    ;;
  no,yes)
    info "VPATH build disabled"
    assign buildpath $srcpath
    distcheck=no
    cd $srcpath
    run ./configure
    ;;
  *,no)
    info "no configure script"
    assign buildpath $srcpath
    cd $srcpath
    ;;
esac

## Discover the release name.
cat >find-distdir.mk <<'EOF'
include Makefile
print-distdir:
	@echo >&3 $(distdir)
EOF
assign distdir \
	$({ make -f find-distdir.mk print-distdir >/dev/null 2>&1; } 3>&1)

## Get a tarball distribution.
case "$distcheck" in
  yes)
    run make $makeopts distcheck
    ;;
  no)
    run make $makeopts dist
    ;;
esac

cd $releasepath

case $native in
  yes)
    if ! tar tf $buildpath/$distdir.tar.gz 2>/dev/null | grep -q RELEASE
    then
      fail "missing RELEASE file in distribution"
    fi
    ;;
esac

run mv $buildpath/$distdir.tar.gz .
case $build in
  release)
    run gpg -u$(mdw-conf releasekey) -ab -o$distdir.tar.gz.gpg \
      $distdir.tar.gz
    ;;
esac

## Maybe build the Debian packages.
case "$debian" in
  yes)
    run tar xvfz $distdir.tar.gz
    cd $distdir
    case $hack_dch in
      yes)
	dver=$(echo $gitver | sed 's/-/+/; s/-/./g')
	now=$(date -R)
	cat - debian/changelog >debian/changelog.new <<EOF
$debsrc ($dver) experimental; urgency=low

  * Hacking in process, not intended for release.

 -- $debname <$debemail>  $now

EOF
	mv debian/changelog.new debian/changelog
	;;
    esac
    run dpkg-buildpackage -k$(mdw-conf releasekey)
    ;;
esac

## Maybe upload Debian packages.
cd $releasepath
case "$upload,$build" in
  yes,test)
    info "Test build: not uploading."
    ;;
  yes,release)
    run rsync $distdir.tar.gz $distdir.tar.gz.gpg \
      $(mdw-conf upload-target ftp.distorted.org.uk:~ftp/pub/mdw/)
    case "$debian" in
      yes)
	run dput -f $(mdw-conf dput-target distorted) *.changes
	;;
    esac
esac

## Tidy up.
case "$clean" in
  yes)
    rm -rf $releasepath/$distdir
    rm -rf $releasepath/_source
    rm -rf $releasepath/_build
    ;;
esac

## Done.
info "All OK."

###----- That's all, folks --------------------------------------------------