#!/bin/sh

# Copyright (C) 2012  Codethink Limited
#
# 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; version 2 of the License.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# Remove all chunk artifacts in the cache except the newest. Morph does
# not currently clean its caches at any point, so this script is necessary
# to avoid running out of disk space.

set -e

usage() {
        echo "Usage: clean-artifact-cache [--all] [CHUNK_NAME]"
        echo
        echo "WARNING: this script removes all but the chunks with the latest"
        echo "mtimes. This is usually what you want, but you should try the"
        echo "script on a small chunk first and trigger a rebuild to make sure"
        echo "that you are not removing artifacts that you still want."
}

if [ -z $1 ]; then
        usage
        exit 0
fi

CHUNK=
case $1 in
        --all)
                CHUNK=*
                ;;
        -*)
                usage
                exit 0
                ;;
        *)
                CHUNK=$1
esac


clean_chunk() {
        ARTIFACT_COUNT=$(ls *.chunk.$1 | wc -l)

        if [ $ARTIFACT_COUNT -lt 2 ]; then
                return
        fi

        echo "$1: $(expr $ARTIFACT_COUNT - 1) stale artifact(s)"

        SKIPPED_LATEST=
        for f in $(ls -1t *.chunk.$1); do
                if [ -z "$SKIPPED_LATEST" ]; then
                        SKIPPED_LATEST=yes
                else
                        rm $(echo $f | cut -c -64).build-log
                        rm $(echo $f | cut -c -64).meta
                        rm $(echo $f | cut -c -64).chunk.$1
                fi
        done
}

test "x$MORPH" = "x" && MORPH=morph

CACHE_DIR=$($MORPH --dump-config | grep cachedir | awk '{print $3}')
ARTIFACT_CACHE="${CACHE_DIR}/artifacts"

cd $ARTIFACT_CACHE
SIZE_BEFORE=$(du -sh . | cut -f 1)

if [ "$CHUNK" = "*" ]; then
        echo "Removing ALL out-of-date chunk artifacts in $ARTIFACT_CACHE"

        for chunk in $(ls *.chunk.* | cut -d '.' -f 3-); do
                clean_chunk $chunk
        done
else
        echo "Removing out of date artifacts for chunk $CHUNK in" \
            "$ARTIFACT_CACHE"
        clean_chunk $CHUNK
fi

SIZE_AFTER=$(du -sh . | cut -f 1)

echo "Artifact cache size before: $SIZE_BEFORE   after: $SIZE_AFTER"