#!/usr/bin/env bash
# ShopDB backup one-shot.
#
# Produces one recoverable set per run and stores it two ways: a plain
# db.sql.gz + manifest.json on the local /backups volume for a fast, repo-free
# restore, and a restic snapshot (db dump + instance tree + manifest) at
# RESTIC_REPOSITORY for a deduped, encrypted, offsite copy.
#
# Sequence:
#   1. mysqldump --single-transaction (InnoDB-consistent, non-blocking)
#   2. manifest.py stamps core+plugin Alembic revisions + image tag
#   3. restic backup the dump + /app/instance + manifest as ONE snapshot
#   4. restic forget --keep-daily 5 --keep-weekly 4 --keep-monthly 6 --prune
#   5. restic check - fail loudly if the repo is unhealthy, so a bad repo is
#      caught on backup night, not restore night.
#
# ASCII only, no emojis - matches the repo style gate.
set -euo pipefail

BACKUPS_ROOT="${SHOPDB_BACKUPS_ROOT:-/backups}"
SITE="${SHOPDB_SITE:-shopdb}"
STAMP="$(date -u +%Y-%m-%dT%H%M%SZ)"
SETNAME="${SITE}-${STAMP}"
SETDIR="${BACKUPS_ROOT}/${SETNAME}"

log() { echo "[backup] $*"; }

mkdir -p "${SETDIR}"

# 1. Database: whole-DB logical dump, consistent and non-blocking on InnoDB.
log "dumping database ${MYSQL_DATABASE} from ${MYSQL_HOST}"
mysqldump \
	--host="${MYSQL_HOST}" \
	--user="${MYSQL_USER}" \
	--password="${MYSQL_PASSWORD}" \
	--single-transaction \
	--routines \
	--triggers \
	--databases "${MYSQL_DATABASE}" \
	| gzip -c > "${SETDIR}/db.sql.gz"
log "database dump written ($(du -h "${SETDIR}/db.sql.gz" | cut -f1))"

# 2. Manifest: the schema stamp that makes a restore a checked operation.
log "writing manifest"
python3 /opt/backup/manifest.py \
	--out "${SETDIR}/manifest.json" \
	--takenat "${STAMP}" \
	--site "${SITE}" \
	--imagetag "${SHOPDB_IMAGE_TAG:-source}" \
	--migrations /app/migrations \
	--plugins /app/plugins

# 3. restic snapshot: db dump + instance tree + manifest, one point in time.
#    Skips gracefully when restic/repo are not configured (local-only sites).
IS_CHECK_PASSED=false
if command -v restic >/dev/null 2>&1 && [ -n "${RESTIC_REPOSITORY:-}" ]; then
	if ! restic snapshots >/dev/null 2>&1; then
		log "initializing restic repository at ${RESTIC_REPOSITORY}"
		restic init
	fi
	log "restic backup (db dump + instance tree + manifest)"
	restic backup \
		--tag "${SITE}" \
		--tag "${SETNAME}" \
		"${SETDIR}/db.sql.gz" \
		"${SETDIR}/manifest.json" \
		/app/instance

	# 4. Retention: any day in the last 5, plus weekly/monthly tail.
	log "pruning per retention policy"
	restic forget \
		--tag "${SITE}" \
		--keep-daily 5 \
		--keep-weekly 4 \
		--keep-monthly 6 \
		--prune

	# 5. Integrity: learn about corruption now, not at restore time.
	log "verifying repository integrity"
	if restic check; then
		IS_CHECK_PASSED=true
		log "restic check passed"
	else
		log "restic check FAILED - repository may be corrupt"
	fi
else
	log "restic not configured - local db.sql.gz + manifest only"
fi

# Record the verification result into the manifest so the UI can badge the set.
python3 /opt/backup/manifest.py \
	--amend "${SETDIR}/manifest.json" \
	--ischeckpassed "${IS_CHECK_PASSED}"

# Clear the request sentinel the UI drops when an operator clicks "Back up now".
rm -f "${BACKUPS_ROOT}/.backup-requested" 2>/dev/null || true

log "backup set ${SETNAME} complete"