Add AuditLog table and Prisma audit extension

src/lib/db.ts

@@ -2,18 +2,172 @@ import pg from 'pg';
 import { PrismaPg } from '@prisma/adapter-pg';
 import { PrismaClient } from '$lib/generated/prisma/client';
 import { env } from '$env/dynamic/private';
+import { getAuditContext } from '$lib/server/audit-context';
+import { describeAction, entityIdFor, sanitizeAuditValue, shouldAudit } from '$lib/server/audit';
 
 let _prisma: PrismaClient | undefined;
+let _base: PrismaClient | undefined;
+let _pool: pg.Pool | undefined;
+
+function getBase(): { base: PrismaClient; pool: pg.Pool } {
+	if (!_base || !_pool) {
+		_pool = new pg.Pool({ connectionString: env.DATABASE_URL });
+		const adapter = new PrismaPg(_pool);
+		_base = new PrismaClient({ adapter });
+	}
+	return { base: _base, pool: _pool };
+}
+
+const roleNameCache = new Map<number, string>();
+
+async function resolveRoleName(base: PrismaClient, roleId: number | null): Promise<string | null> {
+	if (roleId === null) return null;
+	const cached = roleNameCache.get(roleId);
+	if (cached) return cached;
+	try {
+		const role = await base.userRole.findUnique({
+			where: { id: roleId },
+			select: { name: true }
+		});
+		if (role?.name) {
+			roleNameCache.set(roleId, role.name);
+			return role.name;
+		}
+	} catch (e) {
+		console.error('Failed to resolve role name for audit log:', e);
+	}
+	return null;
+}
+
+type Delegate = {
+	findFirst?: (args: unknown) => Promise<unknown>;
+	findMany?: (args: unknown) => Promise<unknown>;
+};
+
+function delegateFor(base: PrismaClient, model: string): Delegate | undefined {
+	const key = model.charAt(0).toLowerCase() + model.slice(1);
+	return (base as unknown as Record<string, unknown>)[key] as Delegate | undefined;
+}
+
+async function readBefore(
+	base: PrismaClient,
+	model: string,
+	operation: string,
+	args: unknown
+): Promise<unknown> {
+	if (operation.startsWith('create')) return null;
+	const delegate = delegateFor(base, model);
+	if (!delegate) return null;
+	const where = (args as { where?: unknown } | null)?.where;
+	try {
+		if (operation === 'updateMany' || operation === 'deleteMany') {
+			return delegate.findMany ? await delegate.findMany({ where, take: 50 }) : null;
+		}
+		return delegate.findFirst ? await delegate.findFirst({ where }) : null;
+	} catch {
+		return null;
+	}
+}
+
+async function writeAuditRow(
+	pool: pg.Pool,
+	base: PrismaClient,
+	entry: {
+		userId: string | null;
+		email: string | null;
+		roleId: number | null;
+		page: string;
+		action: string;
+		entity: string;
+		entityId: string | null;
+		before: unknown;
+		after: unknown;
+		ip: string | null;
+	}
+): Promise<void> {
+	const roleName = await resolveRoleName(base, entry.roleId);
+	await pool.query(
+		`INSERT INTO "AuditLog"
+		 ("id", "createdAt", "userId", "email", "roleId", "roleName", "page", "action", "entity", "entityId", "before", "after", "ip")
+		 VALUES ($1, now(), $2, $3, $4, $5, $6, $7, $8, $9, $10::jsonb, $11::jsonb, $12)`,
+		[
+			crypto.randomUUID(),
+			entry.userId,
+			entry.email,
+			entry.roleId,
+			roleName,
+			entry.page,
+			entry.action,
+			entry.entity,
+			entry.entityId,
+			entry.before === null ? null : JSON.stringify(entry.before),
+			entry.after === null ? null : JSON.stringify(entry.after),
+			entry.ip
+		]
+	);
+}
 
 function getPrisma(): PrismaClient {
-	if (!_prisma) {
-		const pool = new pg.Pool({
-			connectionString: env.DATABASE_URL
-		});
+	if (_prisma) return _prisma;
 
-		const adapter = new PrismaPg(pool);
-		_prisma = new PrismaClient({ adapter });
-	}
+	const { base, pool } = getBase();
+
+	const extended = base.$extends({
+		query: {
+			$allModels: {
+				async $allOperations({ model, operation, args, query }) {
+					if (!shouldAudit(model, operation)) {
+						return query(args);
+					}
+
+					const before = await readBefore(base, model, operation, args);
+					const result = await query(args);
+
+					try {
+						const ctx = getAuditContext();
+						const res = result as { id?: unknown; email?: string; roleId?: number | null } | null;
+
+						let userId = ctx?.userId ?? null;
+						let email = ctx?.email ?? null;
+						let roleId = ctx?.roleId ?? null;
+
+						// Self-signup: attribute the new user to itself since no session exists yet.
+						if (!userId && model === 'User' && operation === 'create' && res) {
+							userId = (res.id as string | undefined) ?? null;
+							email = res.email ?? null;
+							roleId = res.roleId ?? null;
+						}
+
+						const after =
+							operation === 'updateMany' || operation === 'deleteMany'
+								? { count: (result as { count?: number } | null)?.count ?? null }
+								: operation.startsWith('delete')
+									? null
+									: result;
+
+						await writeAuditRow(pool, base, {
+							userId,
+							email,
+							roleId,
+							page: ctx?.page ?? '/system',
+							action: describeAction(operation),
+							entity: model,
+							entityId: entityIdFor(args, result, before),
+							before: sanitizeAuditValue(before),
+							after: sanitizeAuditValue(after),
+							ip: ctx?.ip ?? null
+						});
+					} catch (e) {
+						console.error('Failed to write audit log:', e);
+					}
+
+					return result;
+				}
+			}
+		}
+	});
+
+	_prisma = extended as unknown as PrismaClient;
 	return _prisma;
 }