/**
 * One-time backfill: copies IV_Class_ID (classId) from CW MSSQL ProductCatalog
 * to the API PostgreSQL CatalogItem table.
 *
 * Run with: bun backfill-classid.ts
 */

import { PrismaMssql } from "@prisma/adapter-mssql";
import { PrismaClient as CwPrismaClient } from "./generated/prisma/client";
import pg from "/root/projects/optima/node_modules/.bun/pg@8.20.0+52bd52a0bccfa6a2/node_modules/pg/lib/index.js";

// In dalpuri's .env, DATABASE_URL is the CW MSSQL connection string.
const CW_DATABASE_URL = process.env.DATABASE_URL!;

// The API PostgreSQL URL — hardcoded to avoid env var ambiguity
const API_DATABASE_URL = "postgresql://optima:123web123@localhost:5432/optima";

const cwPrisma = new CwPrismaClient({ adapter: new PrismaMssql(CW_DATABASE_URL) });
const pgPool = new pg.Pool({ connectionString: API_DATABASE_URL });

async function main() {
  console.log("[backfill-classid] Fetching ProductCatalog classId from CW MSSQL...");
  const cwItems = await cwPrisma.productCatalog.findMany({
    select: { catalogRecId: true, classId: true },
  });
  console.log(`[backfill-classid] Fetched ${cwItems.length} CW catalog items`);

  let updated = 0;
  let skipped = 0;
  let failed = 0;

  // Batch updates in groups of 500
  const BATCH_SIZE = 500;
  for (let i = 0; i < cwItems.length; i += BATCH_SIZE) {
    const batch = cwItems.slice(i, i + BATCH_SIZE);
    await Promise.all(
      batch.map(async (item) => {
        try {
          const result = await pgPool.query(
            'UPDATE "CatalogItem" SET "classId" = $1 WHERE "id" = $2',
            [item.classId, item.catalogRecId]
          );
          if (result.rowCount && result.rowCount > 0) {
            updated++;
          } else {
            skipped++;
          }
        } catch (err) {
          failed++;
          console.error(`[backfill-classid] Failed for id=${item.catalogRecId}:`, err);
        }
      })
    );
    console.log(`[backfill-classid] Progress: ${Math.min(i + BATCH_SIZE, cwItems.length)} / ${cwItems.length}`);
  }

  console.log(`[backfill-classid] Done. Updated: ${updated}, Skipped (not in API DB): ${skipped}, Failed: ${failed}`);

  // Verify
  const verifyRes = await pgPool.query<{nonNull: string, total: string}>(
    'SELECT COUNT(*) FILTER (WHERE "classId" IS NOT NULL) as "nonNull", COUNT(*) as total FROM "CatalogItem"'
  );
  const { nonNull, total } = verifyRes.rows[0];
  console.log(`[backfill-classid] Verification: ${nonNull} / ${total} catalog items now have classId`);

  // Breakdown
  const breakdownRes = await pgPool.query<{classId: string | null, count: string}>(
    'SELECT "classId", COUNT(*) as count FROM "CatalogItem" GROUP BY "classId" ORDER BY "classId"'
  );
  for (const row of breakdownRes.rows) {
    const label = row.classId === 'S' ? 'Service/Labor' : row.classId === 'I' ? 'Inventory' : row.classId === 'N' ? 'Non-inventory' : 'null';
    console.log(`  classId=${row.classId ?? 'null'} (${label}): ${row.count}`);
  }
}

main()
  .catch((err) => {
    console.error("[backfill-classid] Fatal error:", err);
    process.exit(1);
  })
  .finally(async () => {
    await Promise.all([cwPrisma.$disconnect(), pgPool.end()]);
  });