#!/usr/bin/env bash

set -u

# Test that src and dest trees are as identical as bup is capable of
# making them.  For now, use rsync -niaHAX ...

usage() {
cat <<EOF
Usage: compare-trees [-h] [-c] [-x] SOURCE DEST
OPTIONS:
  -h
    Display help
  -c
    Check file content (default)
  -x
    Don't check file content (rely on size/timestamps, etc.)
EOF
}

verify_content=" --checksum"

while getopts "hcx" OPTION
do
    case "$OPTION" in
        h) usage; exit 0;;
        c) verify_content=" --checksum";;
        x) verify_content="";;
        ?) usage 1>&2; exit 1;;
    esac
done

shift $(($OPTIND - 1)) || exit $?

if ! test $# -eq 2
then
    usage 1>&2
    exit 1
fi

src="$1"
dest="$2"

tmpfile="$(mktemp /tmp/bup-test-XXXXXXX)" || exit $?
trap "rm -rf '$tmpfile'" EXIT || exit $?

rsync_opts="-niaH$verify_content --delete"

rsync_version=$(rsync --version)
if [[ ! "$rsync_version" =~ "ACLs" ]] || [[ "$rsync_version" =~ "no ACLs" ]]; then
    echo "Not comparing ACLs (not supported by available rsync)" 1>&2
else
    case $OSTYPE in
        cygwin|darwin|netbsd)
            echo "Not comparing ACLs (not yet supported on $OSTYPE)" 1>&2
            ;;
        *)
            rsync_opts="$rsync_opts -A"
            ;;
    esac
fi

xattrs_available=''
if [[ ! "$rsync_version" =~ "xattrs" ]] || [[ "$rsync_version" =~ "no xattrs" ]]; then
    echo "Not comparing xattrs (not supported by available rsync)" 1>&2
else
    xattrs_available=yes
fi

# Even in dry-run mode, rsync may fail if -X is specified and the
# filesystems don't support xattrs.

if test "$xattrs_available"; then
    rsync $rsync_opts -X "$src" "$dest" > "$tmpfile"
    if test $? -ne 0; then
        # Try again without -X
        rsync $rsync_opts "$src" "$dest" > "$tmpfile" || exit $?
    fi
else
    rsync $rsync_opts "$src" "$dest" > "$tmpfile" || exit $?
fi

if test $(wc -l < "$tmpfile") != 0; then
    echo "Differences between $src and $dest" 1>&2
    cat "$tmpfile"
    exit 1
fi

exit 0