refactor: extract numbering logic into numbering.service.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/utils/sequence.ts

@@ -1,46 +0,0 @@
-import prisma from '../config/database';
-
-/**
- * Atomically get and increment the next sequence number for a document type and year.
- * Uses the `number_sequences` table with upsert to avoid race conditions.
- */
-export async function nextSequenceNumber(type: string, year: number): Promise<number> {
-  // Use a transaction with a raw query to atomically increment
-  const result = await prisma.$queryRaw<Array<{ last_number: number }>>`
-    INSERT INTO number_sequences (type, year, last_number)
-    VALUES (${type}, ${year}, 1)
-    ON DUPLICATE KEY UPDATE last_number = last_number + 1;
-    SELECT last_number FROM number_sequences WHERE type = ${type} AND year = ${year};
-  `;
-
-  // $queryRaw with multiple statements may not work on all drivers, use a transaction fallback
-  return result[0]?.last_number ?? 1;
-}
-
-/**
- * Atomically get and increment the next sequence number using Prisma transaction.
- * Compatible with all Prisma drivers.
- */
-export async function getNextNumber(type: string, year: number): Promise<number> {
-  return prisma.$transaction(async (tx) => {
-    // Try to find existing sequence
-    const existing = await tx.number_sequences.findFirst({
-      where: { type, year },
-    });
-
-    if (existing) {
-      const nextNum = (existing.last_number ?? 0) + 1;
-      await tx.number_sequences.update({
-        where: { id: existing.id },
-        data: { last_number: nextNum },
-      });
-      return nextNum;
-    }
-
-    // Create new sequence
-    await tx.number_sequences.create({
-      data: { type, year, last_number: 1 },
-    });
-    return 1;
-  });
-}