# ShopDB backup/restore status + history helper.
#
# WHY this exists: the restore and backup runs happen in the watcher container,
# but the operator watches the UI, which only talks to the api. This helper is
# the bridge: it writes two kinds of state onto the shared /backups volume that
# the api can read.
#
#   1. A LIVE status file (.restore-status.json / .backup-status.json) rewritten
#      at each phase so the UI can show an indeterminate spinner with a phase
#      label (queued, restoring files, loading database, done, failed).
#   2. An append-only HISTORY file (history/restores.json / history/backups.json)
#      that keeps the record of past runs so the UI can list them in a card.
#
# Both writes are atomic (write temp, rename) so the api never reads a half
# written file. History is bounded to the most recent HISTORY_MAX entries.
#
# This file is SOURCED, not executed. It exposes:
#   status_write   <kind> <phase> <setname> [message]
#   history_append <kind> <outcome> <setname> [message]
#
# kind is "restore" or "backup". ASCII only, no emojis - matches the style gate.

STATUS_BACKUPS_ROOT="${SHOPDB_BACKUPS_ROOT:-/backups}"
HISTORY_MAX="${BACKUP_HISTORY_MAX:-50}"

_status_now() { date -u +%Y-%m-%dT%H%M%SZ; }

_status_json_escape() {
	# Escape backslashes and double quotes for embedding in a JSON string.
	printf '%s' "${1:-}" | sed 's/\\/\\\\/g; s/"/\\"/g'
}

# status_write <kind> <phase> <setname> [message]
# Rewrites the live status file for this run kind.
status_write() {
	kind="$1"
	phase="$2"
	setname="${3:-}"
	message="${4:-}"
	statusfile="${STATUS_BACKUPS_ROOT}/.${kind}-status.json"
	tmpfile="${statusfile}.tmp.$$"
	{
		printf '{'
		printf '"kind":"%s",' "$(_status_json_escape "${kind}")"
		printf '"phase":"%s",' "$(_status_json_escape "${phase}")"
		printf '"setname":"%s",' "$(_status_json_escape "${setname}")"
		printf '"message":"%s",' "$(_status_json_escape "${message}")"
		printf '"updatedat":"%s"' "$(_status_now)"
		printf '}\n'
	} > "${tmpfile}" 2>/dev/null || return 0
	mv -f "${tmpfile}" "${statusfile}" 2>/dev/null || rm -f "${tmpfile}" 2>/dev/null
	return 0
}

# history_append <kind> <outcome> <setname> [message]
# Appends a completed run record and trims to HISTORY_MAX newest entries.
history_append() {
	kind="$1"
	outcome="$2"
	setname="${3:-}"
	message="${4:-}"
	historydir="${STATUS_BACKUPS_ROOT}/history"
	historyfile="${historydir}/${kind}s.json"
	tmpfile="${historyfile}.tmp.$$"
	mkdir -p "${historydir}" 2>/dev/null || return 0

	record="$(printf '{"setname":"%s","outcome":"%s","message":"%s","finishedat":"%s"}' \
		"$(_status_json_escape "${setname}")" \
		"$(_status_json_escape "${outcome}")" \
		"$(_status_json_escape "${message}")" \
		"$(_status_now)")"

	if command -v python3 >/dev/null 2>&1; then
		HISTORY_FILE="${historyfile}" HISTORY_RECORD="${record}" \
			HISTORY_MAX="${HISTORY_MAX}" python3 - "${tmpfile}" <<'PY' 2>/dev/null || return 0
import json, os, sys

path = os.environ["HISTORY_FILE"]
record = json.loads(os.environ["HISTORY_RECORD"])
limit = int(os.environ.get("HISTORY_MAX", "50"))
tmp = sys.argv[1]

try:
	with open(path, "r", encoding="utf-8") as handle:
		entries = json.load(handle)
	if not isinstance(entries, list):
		entries = []
except (OSError, ValueError):
	entries = []

entries.append(record)
entries = entries[-limit:]

with open(tmp, "w", encoding="utf-8") as handle:
	json.dump(entries, handle)
os.replace(tmp, path)
PY
	fi
	return 0
}