#!/bin/bash
#
# OAR
#
# build a debian source package from the git repository
#
#

set -e

QUIET=no
TARGET_DIRECTORY=../build-area
REMOTE=no
FORCE=no
GIT_URI=git://scm.gforge.inria.fr/oar/oar.git
GIT_TREEISH=debian/2.5
GIT_UPSTREAM_TREEISH=debian-upstream/2.5
UPSTREAM_TARBALL=


usage() {
    N=$(basename $0)
    cat <<EOF
  $N [-h]
  $N [-q] [-d <directory>] [-m <upstream_tarball>] [-b <git_treeish>] [-t <git_upstream_treeish>] -r [-u <git_uri>]
  $N [-q] [-d <directory>] [-m <upstream_tarball>] [-b <git_treeish>] [-t <git_upstream_treeish>] [-f]

Options:
  -d   target directory (by default '$TARGET_DIRECTORY')
  -h   print this message and exit
  -q   quiet (only write relevant information for automation to stdout)
  -u   specify the git uri to use (by default '$GIT_URI')
  -b   specify the git treeish of the debian branch (by default '$GIT_TREEISH')
  -t   specify the git treeish of the debian upstream branch (by default '$GIT_UPSTREAM_TREEISH')
  -r   use a remote repository
  -f   make the tarball even if there are uncommited changes (only for local repository)
  -m   merge the given upstream tarball into to debian package (this can fail, if quilt fails)

EOF
exit 1
}

log_info() {
    if [ "$QUIET" != "yes" ]; then
        echo -e "$*" >&2
    fi
}

log_exit() {
    ret=$1
    shift
    log_info $*
    [ -d "$TMPDIR" ] && rm -rf "$TMPDIR"
    exit $ret
}

check_if_uncommited_changes() {
    if [ "$FORCE" != "yes" ] && [ -d ".git" ] && [ "$(git status |grep 'working directory clean')" = "" ]; then
        echo "You have uncommited local changes. check with 'git status'."
        echo "(or force the generation with '-f')"
        exit 1
    fi

}

while getopts "hqrfu:b:t:m:d:" options; do
  case $options in
    q) QUIET=yes ;;
    r) REMOTE=yes ;;
    f) FORCE=yes ;; 
    u) GIT_URI="$OPTARG";;
    b) GIT_TREEISH="$OPTARG" ;;
    t) GIT_UPSTREAM_TREEISH="$OPTARG";;
    m) UPSTREAM_TARBALL="$OPTARG" ;;
    d) TARGET_DIRECTORY="$OPTARG";;
    *) usage ;;
  esac
done


shift $(($OPTIND - 1))

[ -z "$TARGET_DIRECTORY" ] && log_exit 1 "you must provide an existing target directory"
target_directory=$(readlink -e "$TARGET_DIRECTORY")

if [ -n "$UPSTREAM_TARBALL" ]; then
    UPSTREAM_TARBALL=$(readlink -e "$UPSTREAM_TARBALL")

    [ ! -f "$UPSTREAM_TARBALL" ] && log_exit 1 "The file $UPSTREAM_TARBALL doesn't exist"
fi


cur_dir=$(pwd)

if [ "$REMOTE" != "yes" ]; then
    git_dir=$(pwd)

    if [ ! -d "$git_dir/.git" ]; then
        echo "$git_dir is not a working git directory. Fail."
        exit 1;
    fi

    check_if_uncommited_changes
    log_info "Using the Git repository '$(pwd)'"

fi

TMPDIR=$(mktemp -d)

if [ "$REMOTE" = "yes" ]; then
    git_dir="$TMPDIR/git"
    mkdir -p "$git_dir"
    log_info "Using the Git repository '$GIT_URI'"
    git clone -q  $GIT_URI "$git_dir"
fi



cd "$git_dir"

log_info "Using the Git tree-ish   '$GIT_TREEISH'"


last_tag=$(git describe $GIT_TREEISH --match "debian/*" --abbrev=0)
last_tag_hash=$(git log --oneline -n 1 "$last_tag" | cut -d' ' -f 1)
git_treeish_hash=$(git log --oneline -n 1 "$GIT_TREEISH" | cut -d' ' -f 1)

is_snapshot=
if [ "$last_tag_hash" = "$git_treeish_hash" ] && [ -n "$(git tag -l $GIT_TREEISH)" ]; then
    is_snapshot=no
    log_info "Generating a released package"
else
    is_snapshot=yes
    log_info "Generating a snapshot package"
fi

upstream_version_tag=$(git describe $GIT_TREEISH --abbrev=0 --match="$GIT_UPSTREAM_TREEISH*")
upstream_version=$(echo "$upstream_version_tag" | sed -e "s%.*/%%")

if [ "$is_snapshot" = "yes" ]; then

    debian_revision_tag=$(git describe $GIT_TREEISH --abbrev=0 --match="debian/$upstream_version*" 2>/dev/null || true)
    if [ -n "$debian_revision_tag" ]; then
        debian_revision=$(echo "$debian_revision_tag" | sed -e "s%.*/.*-%%")
    else
        debian_revision="0"
    fi
     

    debian_revision_number=$(git log --oneline --ancestry-path --no-merges $upstream_version_tag..$GIT_TREEISH | wc -l)
    debian_revision_hash=$(git log --oneline -n 1 $GIT_TREEISH | cut -d' ' -f 1)
    debian_revision="$debian_revision+$debian_revision_number.g$debian_revision_hash"
else
    debian_revision=$(echo "$GIT_TREEISH" | sed -e "s/.*-//")
fi


version="$upstream_version-$debian_revision"

deb_dir="$TMPDIR/deb"
deb_prefix=oar-$version
deb_srcdir="$deb_dir/$deb_prefix"

pristine_prefix=oar_$upstream_version
upstream_tarball=$deb_dir/$pristine_prefix.orig.tar.gz

mkdir "$deb_dir"

git archive --format tar --prefix "$deb_prefix/" "$GIT_TREEISH" | tar xf - -C "$deb_dir"
pristine-tar checkout $upstream_tarball

cd "$deb_srcdir"

log_info "Generating the source package"

if [ "$is_snapshot" = "yes" ]; then
    dch -v "$version" "" -b >/dev/null 2>/dev/null
    dch -r "" >/dev/null 2>/dev/null
fi

dpkg-buildpackage -S -us -uc > /dev/null


log_info "Generating the snapshot package with the merged upstream"
if [ -n "$UPSTREAM_TARBALL" ]; then
    upstream_tarball=$UPSTREAM_TARBALL
    upstream_version=$(echo "$upstream_tarball" | sed -e "s#.*/oar[_-]\(.*\)\(\.orig\)\?\.tar\.gz#\1#")
    version="$upstream_version-$debian_revision"
    uupdate $upstream_tarball -u -v $upstream_version > /dev/null

    cd $deb_dir/oar-$upstream_version
    dch -v "$version" "" >/dev/null 2>/dev/null
    dch -r "" >/dev/null 2>/dev/null
    if ! dpkg-buildpackage -S -us -uc >/dev/null; then
        log_exit 1 "Unable to generate the new source. Fail"
    fi
    
fi

deb_dscfile="$deb_dir/oar_$version.dsc"
deb_changefile="$deb_dir/oar_${version}_source.changes"
deb_tarball="$deb_dir/oar_${version}.debian.tar.gz"

mkdir -p $target_directory/oar_$version

cp  $upstream_tarball \
    $deb_dscfile \
    $deb_changefile \
    $deb_tarball \
    $target_directory/oar_$version

cd $cur_dir

echo "$target_directory/oar_$version"
log_exit 0 "\n### SUCCESS\n\nThe debian source package are in '$TARGET_DIRECTORY/oar_$version'"