'use strict';

const db = require('../src/infra/db');
const sync = require('../src/sync/sync');
const audit = require('../src/audit/audit');
const dashboardSummary = require('../src/precompute/dashboard-summary');
const precompute = require('../src/precompute');
const precomputeService = require('../src/precompute/service');

async function main() {
  precompute.registerAll();
  const legacy = await db.query(
    `SELECT id, employee_id, exam_year, exam_month, submit_time, details, extras
       FROM online_exams
      WHERE COALESCE(JSON_UNQUOTE(JSON_EXTRACT(details, '$.isMissingExam')), 'false') = 'true'`,
  );
  const periods = new Set();

  await db.transaction(async (conn) => {
    for (const row of legacy) {
      const month = `${row.exam_year}-${String(row.exam_month).padStart(2, '0')}`;
      const details = typeof row.details === 'string' ? JSON.parse(row.details) : (row.details || {});
      const extras = typeof row.extras === 'string' ? JSON.parse(row.extras) : row.extras;
      const [existing] = await conn.execute(
        'SELECT id FROM missing_exams WHERE employee_id = ? AND missing_month = ? LIMIT 1',
        [row.employee_id, month],
      );
      if (existing.length === 0) {
        await conn.execute(
          `INSERT INTO missing_exams
             (employee_id, missing_month, reason, import_time, details, extras, version)
           VALUES (?, ?, ?, ?, ?, ?, 0)`,
          [
            row.employee_id,
            month,
            details.reason || '缺考',
            row.submit_time || new Date(),
            JSON.stringify({ ...details, legacyOnlineExamId: row.id }),
            extras == null ? null : JSON.stringify(extras),
          ],
        );
      }
      await conn.execute('DELETE FROM online_exams WHERE id = ?', [row.id]);
      periods.add(`${row.exam_year}-${row.exam_month}`);
    }
  });

  if (legacy.length > 0) {
    await sync.bumpVersions(['online_exams', 'missing_exams']);
    for (const period of periods) {
      const [year, month] = period.split('-').map(Number);
      await precomputeService.onUploadComplete('online_exams', year, month);
    }
    await dashboardSummary.recompute();
    await audit.log({
      clientType: 'system',
      action: 'migrate_missing_exams',
      module: 'missing_exams',
      payload: { migratedCount: legacy.length, periods: [...periods] },
    });
  }

  console.log(JSON.stringify({ migratedCount: legacy.length, periods: [...periods] }));
}

main()
  .catch((error) => {
    console.error(error);
    process.exitCode = 1;
  })
  .finally(() => db.close());