#!/bin/sh
#
#  - automate builds with sbuild and dinstall the result
#
# Copyright (c) 2008–2010 martin f. krafft <madduck@debian.org>
# Released under the terms of the Artistic Licence 2.0.
#
set -eu

ME="${0##*/}"

BUILDDIR="$(mktemp -dt $ME.XXXXXXXX)"
cleanup() {
  cd /tmp && rm -r "$BUILDDIR"
  trap - 1 2 3 4 5 6 7 8 10 11 12 13 14 15
}
trap cleanup 1 2 3 4 5 6 7 8 10 11 12 13 14 15

BUNDLE_DIR="${TMPDIR:-/tmp}"
TARGET_DIR="$PWD"
copy_back_files() {
  echo "Copying files destined for $1 back to $TARGET_DIR..."
  dcmd cp -v "$2" "$TARGET_DIR"
}
dinstall() {
  copy_back_files "$@"
}
print_bundle_location() {
  echo "Bundle available at $@ ."
}
postbuild() {
  :
}

KEYID=

MBUILDRCS="/etc/mbuild/rc $HOME/.mbuildrc $HOME/.mbuild/rc"
for rc in $MBUILDRCS; do
  [ -r "$rc" ] && . "$rc"
done

if [ -z "$KEYID" ]; then
  echo "E: \$KEYID is not defined in rc file." >&2
  exit 1
fi

DEB_BUILD_ARCH="$(dpkg-architecture -qDEB_BUILD_ARCH)"

about()
{
  echo "$ME -- wrapper for sbuild"
  echo "Copyright © martin f. krafft <madduck@debian.org>"
  echo "Released under the terms of the Artistic Licence 2.0"
}

usage()
{
  about
  echo
  echo "Usage: $ME [options] [sbuild_options] file_source.changes"
  echo
  echo "Valid options are:"
  cat <<-_eof | column -s\& -t
	--dist & specify the target distribution (default: from changes file)
	--arch & specify the target architecture (default: $DEB_BUILD_ARCH)
	-sa & pass --force-orig-source to sbuild
	-B & do a binary-only build
	-h|--help & show this output.
	-V|--version & show version information.
	_eof
}

binonly=0
sbuild_args=
sbuild_args_sourceful=
schangesfile=
arch=
for opt in "$@"; do
  case "$opt" in
    -h|--help) usage; exit 0;;
    -V|--version) about; exit 0;;
    --arch=*) arch="${opt#--arch=}";;
    -D) sbuild_args="${sbuild_args:+$sbuild_args }$opt";;
    -sa) sbuild_args="${sbuild_args:+$sbuild_args }--force-orig-source";;
    -B) binonly=1;;
    --*) sbuild_args="${sbuild_args:+$sbuild_args }$opt";;
    *_source.changes)
      if [ -z "$schangesfile" ]; then
        if [ -f "$opt" ] && [ -r "$opt" ]; then
          schangesfile="$opt"
        else
          echo "E: file does not exist: $opt" >&2
          exit 1
        fi
      else
        echo "E: cannot pass more than one source changes file: $opt" >&2
        exit 1
      fi
      ;;
    *)
      echo "E: unknown option: $opt" >&2
      exit 1
      ;;
  esac
done

if [ -z "$schangesfile" ]; then
  usage
  exit 1
fi

dist="$(sed -ne 's,Distribution: ,,p' "$schangesfile")"

schangesfile_basename="${schangesfile##*/}"
packagename="${schangesfile_basename%%_*}"
packagenameversion="${schangesfile_basename%_*}"
debversion="${packagenameversion#*_}"
upstream_version="${debversion%-*}"
dscfile_basename="$packagenameversion".dsc

case "$schangesfile" in
  */*) cd "${schangesfile%/*}";;
  *) :;;
esac
dcmd cp "${schangesfile##*/}" "$BUILDDIR"
schangesfile="$schangesfile_basename"

OLDPWD="$PWD"
cd "$BUILDDIR"

dcmd "$dscfile_basename" | while read f; do
  test -f "$f" && continue

  case "$f" in
    *.tar.gz|*.tar.bz2|*.tar.lzma|*.tar.xz)
      if [ -f "$OLDPWD/$f" ]; then
        echo "I: using existing tarball for $upstream_version…" >&2
        cp $OLDPWD/$f $f
      else
        last_version="$(apt-cache madison $packagename | sed -rne "s,.+(\<${upstream_version}[^[:space:]]+).*,\1,p")"
        echo "I: fetching missing tarball for $upstream_version (from $last_version)…" >&2
        if ! apt-get --tar-only --only-source source "${packagename}=${last_version}"; then
          echo "E: I do not know how to obtain the file: $f" >&2
          exit 1
        fi
      fi
      ;;
    *)
      echo "E: I do not know how to obtain the file: $f" >&2
      exit 1
      ;;
  esac
done

rm $schangesfile
unset schangesfile

[ -z "$arch" ] && arch="$DEB_BUILD_ARCH"

target_arch="$(sed -ne 's,^Architecture: ,,p' $dscfile_basename)"
case "$binonly/$target_arch" in
  1/all)
    echo "E: cannot build arch:all packages with -B." >&2
    exit 1
    ;;
  0/all) arch=all;;
  */any)
    arch="$(schroot -l | sed -rne 's,^sid-([^-]+).*,\1,p' | uniq | tr '\n' ' ')"
    if [ "$binonly" = 0 ]; then
      sbuild_args_sourceful="--source --arch-all"
    fi
    ;;
esac

for a in $arch; do
  echo "I: building $packagenameversion for $a/$dist…" >&2

  case "$a" in
    all)
      arch_arg=--arch-all
      a="$DEB_BUILD_ARCH"
      ;;
    *) --arch=$a;;
  esac

  sbuild $sbuild_args $sbuild_args_sourceful $arch_arg \
    --dist="$dist" --keyid=$KEYID \
    "$dscfile_basename" || ret=$?

  changesfile="${packagenameversion}_${a}.changes"

  if [ -n "$sbuild_args_sourceful" ]; then
    schangesfile="${packagenameversion}_source+${changesfile#${packagenameversion}_}"
    mv "$changesfile" "$schangesfile"
    changesfile="$schangesfile"
  fi

  # subsequent iterations should be binonly
  sbuild_args_sourceful=

  echo "I: running post-build hook ($packagenameversion/$a/$dist)…" >&2
  postbuild "$dist" "$a" "$changesfile"
  echo "I: running dinstall ($packagenameversion/$a/$dist)…" >&2
  dinstall "$dist" "$changesfile"

  echo "I: done building $packagenameversion for $a/$dist" >&2
done

if [ -n "${schangesfile:-}" ]; then
  sarch="${schangesfile##*_}"; sarch=${sarch%.changes}
  combined_arch="$(echo -n "${sarch}+";
                   for i in *.changes; do
                     [ "$i" = "$schangesfile" ] && continue
                     t="${i##*_}"; echo "${t%.changes}"
                   done)"

  if [ -n "$combined_arch" ]; then
    mergechanges *.changes > ${packagenameversion}_${combined_arch}.changes
    arch="$combined_arch"
  fi
fi

bundle="${BUNDLE_DIR}/${packagenameversion}_${arch}_bundle.tar.gz"
tar -chzf "$bundle" *
chmod 644 "$bundle"
print_bundle_location "$bundle"

cleanup

exit 0