snapdir-stores 1.6.0

#!/usr/bin/env bash
#
# snapdir-mock-store: a minimal third-party store used ONLY by the
# external-store shim tests in crates/snapdir-stores/tests/. It is NOT a
# shipped binary and is NOT the oracle — it exists to exercise the documented
# emit-command contract (get-manifest-command / get-fetch-files-command /
# get-push-command) that ExternalStore dispatches against.
#
# Contract per the documented store protocol: each interface subcommand prints
# a shell script on stdout; the caller eval's it. The script does the actual
# transfer. A `mock:///abs/dir` store maps to the local directory `/abs/dir`
# (absolute path embedded in the URL, like file://).
#
set -eEuo pipefail

# --- argument parsing: subcommand + --key value / --key=value -----------------
#
# bash-3.2 compatible (CI macos-latest ships bash 3.2, which has no associative
# arrays): instead of `declare -A opt`, recognized options are stored in plain
# `opt_<name>` scalar variables. Hyphens in option names map to underscores
# (e.g. --staging-dir -> opt_staging_dir) so they are valid identifiers.
command=""
opt_store=""
opt_id=""
opt_staging_dir=""
opt_cache_dir=""

# set_opt <name> <value>: assign opt_<name-with-underscores>=<value>.
set_opt() {
	local name="$1"
	local value="$2"
	name="${name//-/_}"
	eval "opt_${name}=\$value"
}

while [ $# -gt 0 ]; do
	case "$1" in
	get-manifest-command | get-fetch-files-command | get-push-command)
		command="$1"
		shift
		;;
	-v | --version | version)
		echo "snapdir-mock-store 0.0.0"
		exit 0
		;;
	--*=*)
		key="${1%%=*}"
		key="${key#--}"
		set_opt "$key" "${1#*=}"
		shift
		;;
	--*)
		key="${1#--}"
		shift
		set_opt "$key" "${1:-true}"
		shift || true
		;;
	*) shift ;;
	esac
done

store="${opt_store:-}"
id="${opt_id:-}"

# store_dir: mock:///abs/path -> /abs/path (absolute path embedded in the URL,
# like file://; keeps tests hermetic with no shared env between parallel cases).
store_dir="${store#mock://}"
store_dir="${store_dir%/}"

manifest_rel=".manifests/${id:0:3}/${id:3:3}/${id:6:3}/${id:9}"

object_rel() {
	local c="$1"
	echo ".objects/${c:0:3}/${c:3:3}/${c:6:3}/${c:9}"
}

case "$command" in
get-manifest-command)
	cat <<-EOF
		set -eEuo pipefail;
		if ! test -f "${store_dir}/${manifest_rel}"; then
		  echo "ID '${id}' not found on --store '${store}'." >&2;
		  exit 1;
		fi;
		cat "${store_dir}/${manifest_rel}";
	EOF
	;;

get-push-command)
	staging_dir="${opt_staging_dir:?Missing --staging-dir}"
	staging_dir="${staging_dir%/}"
	echo "set -eEuo pipefail;"
	if test -f "${store_dir}/${manifest_rel}"; then
		echo 'echo "Manifest already exists on store.";'
		exit 0
	fi
	# objects BEFORE manifest. The `|| [[ -n ... ]]` tolerates a manifest whose
	# final line lacks a trailing newline (snapdir-core's Display omits it).
	while IFS=' ' read -r ptype _perm checksum _size _path || [[ -n ${ptype:-} ]]; do
		[[ ${ptype:-} == "F" ]] || continue
		rel="$(object_rel "${checksum}")"
		echo "mkdir -p \"${store_dir}/$(dirname "${rel}")\";"
		echo "cp \"${staging_dir}/${rel}\" \"${store_dir}/${rel}\";"
	done <"${staging_dir}/${manifest_rel}"
	echo "mkdir -p \"${store_dir}/$(dirname "${manifest_rel}")\";"
	echo "cp \"${staging_dir}/${manifest_rel}\" \"${store_dir}/${manifest_rel}\";"
	;;

get-fetch-files-command)
	cache_dir="${opt_cache_dir:?Missing --cache-dir}"
	cache_dir="${cache_dir%/}"
	echo "set -eEuo pipefail;"
	# manifest arrives on stdin (tolerate a missing final newline)
	while IFS=' ' read -r ptype _perm checksum _size _path || [[ -n ${ptype:-} ]]; do
		[[ ${ptype:-} == "F" ]] || continue
		rel="$(object_rel "${checksum}")"
		echo "mkdir -p \"${cache_dir}/$(dirname "${rel}")\";"
		echo "if ! test -f \"${store_dir}/${rel}\"; then echo \"ERROR: missing object ${checksum}\" >&2; exit 1; fi;"
		echo "cp \"${store_dir}/${rel}\" \"${cache_dir}/${rel}\";"
	done
	;;

*)
	echo "Unknown command '${command}'" >&2
	exit 1
	;;
esac