#!/usr/bin/env node
import { sequelize } from '../utils/sequelize.js';

const run = async () => {
  try {
    await sequelize.authenticate();
    console.log('✅ DB connection OK');

    const queries = {
      totalDue: `SELECT count(*)::int AS total_due FROM community.vocab_srs_item WHERE next_due_at <= now()`,
      byStage: `SELECT stage, count(*)::int AS cnt FROM community.vocab_srs_item WHERE next_due_at <= now() GROUP BY stage ORDER BY stage`,
      perDay30: `SELECT date(next_due_at) AS day, count(*)::int AS cnt FROM community.vocab_srs_item WHERE next_due_at <= now() GROUP BY day ORDER BY day DESC LIMIT 30`,
      createdToday: `SELECT count(*)::int AS created_today FROM community.vocab_srs_item WHERE date(created_at) = current_date`,
      recentNextDue: `SELECT item_key, course_id, stage, next_due_at, created_at FROM community.vocab_srs_item WHERE next_due_at > now() - interval '1 day' ORDER BY next_due_at ASC LIMIT 200`
    };

    const [totalRes] = await sequelize.query(queries.totalDue, { type: sequelize.QueryTypes.SELECT });
    console.log('\nTotal due items: ', totalRes?.total_due ?? 'N/A');

    const byStage = await sequelize.query(queries.byStage, { type: sequelize.QueryTypes.SELECT });
    console.log('\nDue by stage:');
    console.table(byStage);

    const perDay = await sequelize.query(queries.perDay30, { type: sequelize.QueryTypes.SELECT });
    console.log('\nDue per day (last 30):');
    console.table(perDay);

    const [createdRes] = await sequelize.query(queries.createdToday, { type: sequelize.QueryTypes.SELECT });
    console.log('\nCreated today: ', createdRes?.created_today ?? 'N/A');

    const recent = await sequelize.query(queries.recentNextDue, { type: sequelize.QueryTypes.SELECT });
    console.log('\nExamples of items with next_due_at in the last 24h:');
    console.table(recent.slice(0, 50));

    // Summary recommendation
    console.log('\nNotes:');
    console.log('- If many items are in stage 0/1 and created_today > 0, check code paths that call _ensureSrsItems.');
    console.log('- If many next_due_at are very recent, items may be created with next_due_at = now() causing large due counts.');
  } catch (err) {
    console.error('Error running diagnostics:', err);
    process.exitCode = 2;
  } finally {
    try { await sequelize.close(); } catch (_) {}
  }
};

run();