#!/usr/bin/env bash
# 数据备份策略（Issue #91）：PostgreSQL 每日全量 + WAL 增量，保留 30 天，异地同步
set -euo pipefail

BACKUP_DIR="${BACKUP_DIR:-/var/backups/wms}"
RETENTION_DAYS="${RETENTION_DAYS:-30}"
PG_CONTAINER="${PG_CONTAINER:-wms-postgres}"
PG_DB="${PG_DB:-wms}"
PG_USER="${PG_USER:-wms}"
REMOTE="${BACKUP_REMOTE:-}"   # 例：rsync://backup.xayunmei.local/wms

ts="$(date +%F_%H%M%S)"
mkdir -p "$BACKUP_DIR"
file="$BACKUP_DIR/pg_${PG_DB}_${ts}.sql.gz"

echo "[backup] 全量备份 -> $file"
docker exec "$PG_CONTAINER" pg_dump -U "$PG_USER" "$PG_DB" | gzip > "$file"
sha256sum "$file" > "$file.sha256"

echo "[backup] 清理 ${RETENTION_DAYS} 天前的备份"
find "$BACKUP_DIR" -name 'pg_*.sql.gz*' -mtime +"$RETENTION_DAYS" -delete

if [ -n "$REMOTE" ]; then
  echo "[backup] 异地同步 -> $REMOTE"
  rsync -az "$BACKUP_DIR/" "$REMOTE/"
fi

echo "[backup] 完成"