Remap occupied furniture IDs during Catalog Studio imports

src/lib/services/furniture-id-reservation.ts

@@ -0,0 +1,56 @@
+import { sql } from "drizzle-orm";
+import { db } from "@/lib/db";
+import { findFurniDataIdConflict } from "./furni-data";
+
+let reservation: Promise<void> = Promise.resolve();
+/** Reserve both SQL and client identifiers by inserting while holding the local queue.
+ * The primary key handles competing processes; only duplicate-key failures retry.
+ */
+export async function reserveFurnitureId(
+	preferred: number,
+	classname: string,
+	insert: (id: number) => Promise<void>,
+): Promise<number> {
+	let release!: () => void;
+	const previous = reservation;
+	reservation = new Promise<void>((resolve) => {
+		release = resolve;
+	});
+	await previous;
+	try {
+		let candidate = preferred;
+		for (let attempt = 0; attempt < 100; attempt++) {
+			if (
+				!Number.isSafeInteger(candidate) ||
+				candidate < 1 ||
+				candidate > 2147483647
+			)
+				throw new Error("No valid furniture ID is available");
+			const [owners] = (await db.execute(
+				sql`SELECT item_name FROM items_base WHERE id = ${candidate} OR sprite_id = ${candidate} LIMIT 1`,
+			)) as unknown as [Array<{ item_name: string }>, unknown];
+			const occupied =
+				owners.length > 0 ||
+				!!(await findFurniDataIdConflict(candidate, classname));
+			if (!occupied) {
+				try {
+					await insert(candidate);
+					return candidate;
+				} catch (error) {
+					const cause =
+						(error as { cause?: { code?: string; errno?: number } }).cause ??
+						(error as { code?: string; errno?: number });
+					if (cause.code !== "ER_DUP_ENTRY" && cause.errno !== 1062)
+						throw error;
+				}
+			}
+			const [rows] = (await db.execute(
+				sql`SELECT GREATEST(COALESCE(MAX(id), 0), COALESCE(MAX(sprite_id), 0)) AS maximum FROM items_base`,
+			)) as unknown as [Array<{ maximum: number | string }>, unknown];
+			candidate = Math.max(candidate + 1, Number(rows[0]?.maximum ?? 0) + 1);
+		}
+		throw new Error("Cannot reserve a free furniture ID; retry the import");
+	} finally {
+		release();
+	}
+}