import { prisma } from '../prisma.js';

/**
 * Record an audit log entry. Non-blocking: catches and swallows errors
 * to avoid slowing down the operation being audited.
 */
export function logAction(
	userId: string | null,
	action: string,
	entityType: string,
	entityId: string,
	details?: Record<string, unknown>
): void {
	prisma.auditLog
		.create({
			data: {
				userId,
				action,
				entityType,
				entityId,
				details: details ? JSON.stringify(details) : '{}'
			}
		})
		.catch((err) => {
			// Non-blocking but observable: log to stderr so a failing audit trail
			// (e.g. DB full, locked) is visible in container logs.
			 
			console.warn(
				`[audit] failed to record ${action} ${entityType}:${entityId}:`,
				err
			);
		});
}

/**
 * Query audit logs with filters and pagination.
 */
export async function getAuditLogs(options?: {
	action?: string;
	entityType?: string;
	userId?: string;
	startDate?: string;
	endDate?: string;
	limit?: number;
	offset?: number;
}) {
	const where: Record<string, unknown> = {};

	if (options?.action) {
		where.action = options.action;
	}
	if (options?.entityType) {
		where.entityType = options.entityType;
	}
	if (options?.userId) {
		where.userId = options.userId;
	}

	const dateFilter: Record<string, Date> = {};
	if (options?.startDate) {
		dateFilter.gte = new Date(options.startDate);
	}
	if (options?.endDate) {
		dateFilter.lte = new Date(options.endDate);
	}
	if (Object.keys(dateFilter).length > 0) {
		where.createdAt = dateFilter;
	}

	const limit = options?.limit ?? 50;
	const offset = options?.offset ?? 0;

	const [logs, total] = await Promise.all([
		prisma.auditLog.findMany({
			where,
			orderBy: { createdAt: 'desc' },
			take: limit,
			skip: offset,
			include: {
				user: {
					select: { id: true, displayName: true, email: true }
				}
			}
		}),
		prisma.auditLog.count({ where })
	]);

	return { logs, total };
}

/**
 * Delete audit logs older than the given retention period.
 */
export async function pruneOldLogs(retentionDays: number = 90) {
	const cutoff = new Date(Date.now() - retentionDays * 24 * 60 * 60 * 1000);

	const result = await prisma.auditLog.deleteMany({
		where: {
			createdAt: { lt: cutoff }
		}
	});

	return result.count;
}