refactor: extract numbering logic into numbering.service.ts

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

src/services/numbering.service.ts

@@ -0,0 +1,71 @@
+import prisma from '../config/database';
+
+/**
+ * Shared number generator for orders and projects.
+ * Format: YYtypeCode + 4-digit sequence (e.g., 26710003)
+ * Queries MAX from both orders and projects tables.
+ */
+export async function generateSharedNumber(): Promise<string> {
+  const settings = await prisma.company_settings.findFirst({ select: { order_type_code: true } });
+  const typeCode = settings?.order_type_code || '71';
+  const yy = String(new Date().getFullYear()).slice(-2);
+  const prefix = `${yy}${typeCode}`;
+  const prefixLen = prefix.length;
+  const likePattern = `${prefix}%`;
+
+  const result = await prisma.$queryRaw<[{ max_seq: bigint | null }]>`
+    SELECT COALESCE(MAX(seq), 0) as max_seq FROM (
+      SELECT CAST(SUBSTRING(order_number, ${prefixLen} + 1) AS UNSIGNED) AS seq
+      FROM orders WHERE order_number LIKE ${likePattern}
+      UNION ALL
+      SELECT CAST(SUBSTRING(project_number, ${prefixLen} + 1) AS UNSIGNED) AS seq
+      FROM projects WHERE project_number LIKE ${likePattern}
+    ) combined
+  `;
+  const nextNum = Number(result[0]?.max_seq ?? 0) + 1;
+  return `${prefix}${String(nextNum).padStart(4, '0')}`;
+}
+
+/**
+ * Next offer number. Queries MAX from quotations table.
+ * Format: YEAR/PREFIX/NNN (e.g., 2026/NA/008)
+ */
+export async function generateOfferNumber(): Promise<string> {
+  const settings = await prisma.company_settings.findFirst({ select: { quotation_prefix: true } });
+  const prefix = settings?.quotation_prefix || 'NA';
+  const year = new Date().getFullYear();
+  const likePattern = `${year}/${prefix}/%`;
+
+  const result = await prisma.$queryRaw<[{ max_num: bigint | null }]>`
+    SELECT COALESCE(MAX(CAST(SUBSTRING_INDEX(quotation_number, '/', -1) AS UNSIGNED)), 0) as max_num
+    FROM quotations
+    WHERE quotation_number LIKE ${likePattern}
+  `;
+  const nextNum = Number(result[0]?.max_num ?? 0) + 1;
+  return `${year}/${prefix}/${String(nextNum).padStart(3, '0')}`;
+}
+
+/**
+ * Next invoice number via atomic sequence table.
+ */
+export async function generateInvoiceNumber(year: number): Promise<number> {
+  return prisma.$transaction(async (tx) => {
+    const existing = await tx.number_sequences.findFirst({
+      where: { type: 'invoice', 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;
+    }
+
+    await tx.number_sequences.create({
+      data: { type: 'invoice', year, last_number: 1 },
+    });
+    return 1;
+  });
+}