/**
 * Migrate received invoice files from DB BLOB to NAS storage.
 *
 * Usage: NAS_FINANCIALS_PATH=/mnt/nas/financials npx tsx scripts/migrate-received-invoices-to-nas.ts
 */

import "../src/config/env";
import fs from "fs";
import { PrismaClient } from "@prisma/client";
import { nasFinancialsManager } from "../src/services/nas-financials-manager";

const prisma = new PrismaClient();

async function main() {
  if (!nasFinancialsManager.isConfigured()) {
    console.error(
      "NAS_FINANCIALS_PATH is not configured or path does not exist.",
    );
    process.exit(1);
  }

  const records = await prisma.received_invoices.findMany({
    where: { file_data: { not: null }, file_path: null },
    select: {
      id: true,
      file_data: true,
      file_name: true,
      month: true,
      year: true,
    },
  });

  console.log(`Found ${records.length} invoices to migrate.`);

  let migrated = 0;
  let failed = 0;

  for (const rec of records) {
    if (!rec.file_data) continue;

    const fileName = rec.file_name || `invoice-${rec.id}.pdf`;
    const result = nasFinancialsManager.saveReceivedInvoice(
      fileName,
      rec.year,
      rec.month,
      Buffer.from(rec.file_data),
    );

    if ("error" in result) {
      console.error(`  FAIL id=${rec.id}: ${result.error}`);
      failed++;
      continue;
    }

    // Read-back verification before we null out the ONLY DB copy of the bytes.
    // The manager uses writeFileSync (synchronous) and returns a relative path;
    // resolve it back to disk and confirm the file exists and its size matches
    // the source buffer. A 0-byte/truncated/corrupt write would otherwise lose
    // the invoice permanently once file_data is set to null. If verification
    // fails we KEEP file_data and report the row as failed.
    const expectedSize = rec.file_data.length;
    const readBack = nasFinancialsManager.readReceivedInvoice(result.filePath);
    let writtenSize = -1;
    if (readBack) {
      writtenSize = readBack.data.length;
    } else {
      // Fall back to a direct stat in case readReceivedInvoice's path guard
      // rejects an otherwise-valid path; either way we need a confirmed size.
      try {
        writtenSize = fs.statSync(
          (nasFinancialsManager as unknown as { basePath: string }).basePath +
            "/" +
            result.filePath,
        ).size;
      } catch {
        writtenSize = -1;
      }
    }

    if (writtenSize !== expectedSize) {
      console.error(
        `  FAIL id=${rec.id}: read-back mismatch (expected ${expectedSize} bytes, got ${writtenSize}); keeping DB copy`,
      );
      failed++;
      continue;
    }

    await prisma.received_invoices.update({
      where: { id: rec.id },
      data: { file_path: result.filePath, file_data: null },
    });

    migrated++;
    if (migrated % 50 === 0) {
      console.log(`  Progress: ${migrated}/${records.length}...`);
    }
  }

  console.log(
    `Done. Migrated: ${migrated}, Failed: ${failed}, Total: ${records.length}`,
  );
}

main()
  .catch((e) => {
    console.error(e);
    process.exit(1);
  })
  .finally(() => prisma.$disconnect());