#!/usr/bin/env bash
# ShopDB restore.
#
# The DANGEROUS half of the pair, so it is deliberately guarded. A restore is
# only safe onto code whose schema is at least the set's - otherwise restored
# rows reference columns the live schema has not applied yet and every query on
# those tables 500s. This script refuses an incompatible restore rather than
# leaving the site half-broken.
#
# Usage (from the backup container):
#   docker compose -f docker-compose.yml -f docker-compose.backup.yml \
#     run --rm --entrypoint /opt/backup/restore.sh backup <snapshot-set-name>
#
# It does NOT roll back code - that is git's job (git checkout <tag> && build).
# Restore code FIRST, bring the schema up (flask db upgrade + plugin
# upgrade-all), THEN run this to load the data.
#
# ASCII only, no emojis - matches the repo style gate.
set -euo pipefail

BACKUPS_ROOT="${SHOPDB_BACKUPS_ROOT:-/backups}"
SETNAME="${1:-}"

log() { echo "[restore] $*"; }
die() { echo "[restore] ERROR: $*" >&2; exit 1; }

[ -n "${SETNAME}" ] || die "usage: restore.sh <snapshot-set-name>"

SETDIR="${BACKUPS_ROOT}/${SETNAME}"
DBDUMP="${SETDIR}/db.sql.gz"

# Prefer the local fast path; fall back to pulling the set out of restic.
if [ ! -f "${DBDUMP}" ]; then
	log "local dump not found; restoring set from restic"
	command -v restic >/dev/null 2>&1 || die "restic not available and no local dump"
	restic restore latest --target / --include "${SETDIR}" \
		|| die "restic restore of ${SETNAME} failed"
fi
[ -f "${DBDUMP}" ] || die "no db.sql.gz for set ${SETNAME}"

# Compatibility gate: the running schema must cover the set's stamped heads.
log "checking schema compatibility"
CURRENT_HEADS="$(python3 /opt/backup/manifest.py \
	--out /tmp/current-manifest.json \
	--migrations /app/migrations --plugins /app/plugins \
	>/dev/null 2>&1 && python3 -c \
	'import json;print(",".join(sorted(json.load(open("/tmp/current-manifest.json"))["schemarev"]["core"])))')"
SET_HEADS="$(python3 -c \
	'import json,sys;print(",".join(sorted(json.load(open(sys.argv[1]))["schemarev"]["core"])))' \
	"${SETDIR}/manifest.json" 2>/dev/null || echo "")"

if [ -z "${SET_HEADS}" ]; then
	die "set ${SETNAME} has no readable manifest - refusing an unverified restore"
fi
if [ "${CURRENT_HEADS}" != "${SET_HEADS}" ]; then
	log "current heads : ${CURRENT_HEADS}"
	log "set heads     : ${SET_HEADS}"
	die "schema mismatch - bring code to the set's revision, run 'flask db upgrade' and 'flask plugin upgrade-all', then retry"
fi

# Files first, then DB, so the two land together.
if command -v restic >/dev/null 2>&1 && [ -n "${RESTIC_REPOSITORY:-}" ]; then
	log "restoring instance files from restic"
	restic restore latest --target / --include /app/instance \
		|| die "restic restore of instance files failed"
fi

log "loading database dump"
gunzip -c "${DBDUMP}" | mysql \
	--host="${MYSQL_HOST}" \
	--user="${MYSQL_USER}" \
	--password="${MYSQL_PASSWORD}" \
	|| die "database load failed"

rm -f "${BACKUPS_ROOT}/.restore-requested" 2>/dev/null || true
log "restore of ${SETNAME} complete"