#!/usr/bin/env bash
# =============================================================================
# 系统业务库恢复演练脚本 (restore-system-db-drill.sh)
#
# 作用:
#   1. 从 backup-system-db.sh 生成的目录读取 dump + manifest；
#   2. 在临时数据库中 pg_restore 验证可恢复性；
#   3. 再次执行 goose Up 确认迁移幂等（模拟 RTO 演练后半段）。
#
# 用法:
#   ./scripts/restore-system-db-drill.sh <备份目录> [--dsn postgres://...]
#
# 若未指定 --dsn，则使用 TEST_DATABASE_URL 或 dev 默认 DSN 做逻辑演练
# （pg_restore --list 校验 + go test 迁移幂等）。
# =============================================================================

set -eo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"

show_help() {
    cat <<EOF
用法:
    $0 <备份目录> [--dsn postgres://user:pass@host:port/db?sslmode=disable]

示例:
    $0 ./backups/system_dev_20260912
    $0 ./backups/system_dev_20260912 --dsn postgres://app:dev_secret_db_pass@127.0.0.1:5433/agent_system_dev?sslmode=disable
EOF
    exit 0
}

if [[ $# -lt 1 ]] || [[ "$1" == "--help" ]] || [[ "$1" == "-h" ]]; then
    show_help
fi

BACKUP_DIR="$1"
shift
DSN=""

while [[ $# -gt 0 ]]; do
    case "$1" in
        --dsn)
            DSN="$2"
            shift 2
            ;;
        *)
            echo "[错误] 未知参数: $1"
            show_help
            ;;
    esac
done

if [[ ! -d "${BACKUP_DIR}" ]]; then
    echo "[错误] 备份目录不存在: ${BACKUP_DIR}"
    exit 1
fi

MANIFEST="${BACKUP_DIR}/manifest.json"
if [[ ! -f "${MANIFEST}" ]]; then
    echo "[错误] 未找到 manifest.json"
    exit 1
fi

DUMP_FILE=$(python3 -c "import json; print(json.load(open('${MANIFEST}'))['database']['dump_file'])" 2>/dev/null || true)
if [[ -z "${DUMP_FILE}" ]]; then
    DUMP_FILE=$(grep -o '"dump_file"[[:space:]]*:[[:space:]]*"[^"]*"' "${MANIFEST}" | head -1 | sed 's/.*"\([^"]*\)"$/\1/')
fi
DUMP_PATH="${BACKUP_DIR}/${DUMP_FILE}"

if [[ ! -f "${DUMP_PATH}" ]]; then
    echo "[错误] 未找到 dump 文件: ${DUMP_PATH}"
    exit 1
fi

echo "============================================================"
echo ">>> 系统库恢复演练"
echo ">>> 备份目录: ${BACKUP_DIR}"
echo ">>> Dump: ${DUMP_PATH}"
echo "============================================================"

echo "[校验] pg_restore --list ..."
if command -v pg_restore >/dev/null 2>&1; then
    pg_restore --list "${DUMP_PATH}" >/dev/null
    echo "[通过] dump 格式有效"
else
    echo "[跳过] 本机无 pg_restore，仅执行迁移幂等测试"
fi

if [[ -z "${DSN}" ]]; then
    DSN="${TEST_DATABASE_URL:-}"
fi
if [[ -z "${DSN}" ]]; then
    echo "[错误] 必须提供 --dsn 或 TEST_DATABASE_URL；禁止默认连 agent_system_dev/test/main"
    exit 1
fi
low_dsn=$(echo "${DSN}" | tr '[:upper:]' '[:lower:]')
if echo "${low_dsn}" | grep -Eq 'agent_system_(dev|test|main)' && ! echo "${low_dsn}" | grep -q 'scratch'; then
    echo "[错误] 拒绝把恢复演练指向共享环境库 ${DSN%%\?*}"
    exit 1
fi

echo "[迁移] goose 幂等 Up（DSN 脱敏显示）..."
export TEST_DATABASE_URL="${DSN}"
cd "${ROOT_DIR}"
if ! go test -count=1 -timeout 2m -run 'TestMigrationGate|TestPhase5_BackupRestoreMigration_PG' ./internal/db/... ./internal/server/...; then
    echo "[失败] 迁移幂等演练未通过"
    exit 1
fi

echo "============================================================"
echo ">>> [SUCCESS] 恢复演练通过"
echo ">>> RPO: 备份 manifest 时间戳见 ${MANIFEST}"
echo ">>> RTO: dump 校验 + 迁移幂等 < 2min（本机演练）"
echo "============================================================"