#!/usr/bin/env bash
# Archive old build images on the fileserver before publishing new ones.
#
# Usage: tools/archive-images.sh <ssh-target> <images-dir> <archive-dir> <pattern>...
#
# Zero matching files is fine (nothing to archive yet); a missing directory
# or a failed move aborts non-zero so CI stops before publishing.
# The remote half is piped to `bash -s` over stdin so there is no nested
# shell quoting to get wrong.

set -euo pipefail

die() { echo "error: $*" >&2; exit 1; }

(( $# >= 4 )) || die "usage: $0 <ssh-target> <images-dir> <archive-dir> <pattern>..."

target=$1 images_dir=$2 archive_dir=$3
shift 3
patterns=("$@")

for v in "$images_dir" "$archive_dir" "${patterns[@]}"; do
	case $v in
		*[[:space:]\'\"]*) die "unsafe argument (whitespace/quotes): $v" ;;
	esac
done

echo "Archiving previous images on $target:"
printf '  pattern: %s\n' "${patterns[@]}"

# Assignments prefixed to `bash -s` are parsed by the remote shell as
# environment variables for the script below; the quoted heredoc marker
# keeps every byte of the payload literal until bash executes it.
ssh "$target" "IMAGES_DIR=$images_dir ARCHIVE_DIR=$archive_dir bash -s" <<'REMOTE'
set -euo pipefail
shopt -s nullglob

if [ ! -d "$IMAGES_DIR" ]; then
	echo "error: images dir not found: $IMAGES_DIR" >&2
	exit 1
fi
if [ ! -d "$ARCHIVE_DIR" ]; then
	echo "error: archive dir not found: $ARCHIVE_DIR" >&2
	exit 1
fi

moved=0
for pat in "${PATTERNS[@]}"; do
	for f in "$IMAGES_DIR"/$pat; do
		echo "  archiving $(basename "$f")"
		mv "$f" "$ARCHIVE_DIR/"
		moved=$((moved + 1))
	done
done

echo "Archived $moved file(s)."
REMOTE