const express = require('express');
const router = express.Router();
const { query } = require('../config/db');

// GET /api/stats — публичная статистика блога
router.get('/', async (_, res) => {
  try {
    const { rows: countRow } = await query(
      `SELECT
         COUNT(*)::int as articles_count,
         COALESCE(SUM(LENGTH(content) - LENGTH(REPLACE(content, ' ', '')) + 1), 0)::int as total_words,
         COALESCE(SUM(reading_time), 0)::int as total_reading_min,
         COALESCE(SUM(views), 0)::int as total_views
       FROM articles WHERE status='published'`
    );

    const { rows: jobsRow } = await query(
      `SELECT
         COALESCE(SUM(tokens_in), 0)::int as tokens_in,
         COALESCE(SUM(tokens_out), 0)::int as tokens_out,
         COUNT(*)::int as jobs_done
       FROM generation_jobs WHERE status='done' AND type='article'`
    );

    const { rows: latestRow } = await query(
      `SELECT MAX(published_at) as latest FROM articles WHERE status='published'`
    );

    res.json({
      ...countRow[0],
      ...jobsRow[0],
      latest_published: latestRow[0]?.latest || null,
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// GET /api/stats/live — «прямо сейчас»: текущая активность и активность за 7 дней
router.get('/live', async (_, res) => {
  try {
    // Последняя опубликованная статья
    const { rows: latestRow } = await query(
      `SELECT a.id, a.slug, a.title, a.published_at, j.tokens_in, j.tokens_out
       FROM articles a
       LEFT JOIN generation_jobs j ON j.id=a.job_id
       WHERE a.status='published'
       ORDER BY a.published_at DESC LIMIT 1`
    );

    // Сейчас обрабатывается?
    const { rows: processing } = await query(
      `SELECT id, type, topic, created_at FROM generation_jobs
       WHERE status IN ('pending','processing')
       ORDER BY created_at DESC LIMIT 1`
    );

    // Активность по дням за 7 дней
    const { rows: byDay } = await query(
      `SELECT
         DATE_TRUNC('day', published_at) as day,
         COUNT(*)::int as cnt
       FROM articles
       WHERE status='published' AND published_at > NOW() - INTERVAL '7 days'
       GROUP BY day ORDER BY day ASC`
    );

    // Запоняем пропущенные дни нулями
    const week = [];
    for (let i = 6; i >= 0; i--) {
      const d = new Date();
      d.setDate(d.getDate() - i);
      d.setHours(0, 0, 0, 0);
      const dayStr = d.toISOString().slice(0, 10);
      const found = byDay.find(r => r.day && new Date(r.day).toISOString().slice(0, 10) === dayStr);
      week.push({ day: dayStr, cnt: found ? found.cnt : 0 });
    }

    res.json({
      latest: latestRow[0] || null,
      processing: processing[0] || null,
      week,
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;