#!/usr/bin/env node

/**
 * Script zum Ausführen von VACUUM auf Tabellen mit hohem Bloat
 * 
 * Führt VACUUM ANALYZE auf Tabellen aus, die:
 * - Hohen Bloat-Anteil haben (> 20% tote Zeilen)
 * - Seit mehr als 7 Tagen nicht gevacuumt wurden
 * - Viele tote Zeilen haben (> 1000)
 */

import './config/loadEnv.js';
import { sequelize } from './utils/sequelize.js';

async function main() {
    try {
        console.log('🧹 Datenbank-Vacuum\n');
        console.log('='.repeat(60) + '\n');

        // Finde Tabellen, die Vacuum benötigen
        const [tablesToVacuum] = await sequelize.query(`
            SELECT 
                schemaname || '.' || relname as table_name,
                n_dead_tup,
                n_live_tup,
                CASE 
                    WHEN n_live_tup > 0 THEN round((n_dead_tup::numeric / n_live_tup::numeric) * 100, 2)
                    ELSE 0
                END as dead_percent,
                last_vacuum,
                last_autovacuum,
                pg_size_pretty(pg_total_relation_size(schemaname||'.'||relname)) as table_size
            FROM pg_stat_user_tables
            WHERE schemaname IN ('falukant_data', 'falukant_type', 'community', 'logs')
            AND (
                (n_dead_tup > 1000 AND (n_live_tup = 0 OR (n_dead_tup::numeric / NULLIF(n_live_tup, 0)) > 0.2))
                OR (last_vacuum IS NULL AND last_autovacuum IS NULL AND n_dead_tup > 0)
                OR (
                    (last_vacuum < now() - interval '7 days' OR last_vacuum IS NULL)
                    AND (last_autovacuum < now() - interval '7 days' OR last_autovacuum IS NULL)
                    AND n_dead_tup > 100
                )
            )
            ORDER BY n_dead_tup DESC;
        `);

        if (tablesToVacuum.length === 0) {
            console.log('✅ Keine Tabellen benötigen Vacuum.\n');
            await sequelize.close();
            process.exit(0);
        }

        console.log(`📋 Gefunden: ${tablesToVacuum.length} Tabellen benötigen Vacuum\n`);

        // Zeige Tabellen
        console.log('Tabellen, die gevacuumt werden:');
        tablesToVacuum.forEach((t, i) => {
            console.log(`   ${i + 1}. ${t.table_name}`);
            console.log(`      Größe: ${t.table_size}, Tote Zeilen: ${parseInt(t.n_dead_tup).toLocaleString()} (${t.dead_percent}%)`);
        });
        console.log('');

        // Frage Bestätigung
        const readline = require('readline');
        const rl = readline.createInterface({
            input: process.stdin,
            output: process.stdout
        });

        const answer = await new Promise((resolve) => {
            rl.question('Möchtest du VACUUM ANALYZE auf diesen Tabellen ausführen? (j/n): ', resolve);
        });
        rl.close();

        if (answer.toLowerCase() !== 'j' && answer.toLowerCase() !== 'y' && answer.toLowerCase() !== 'ja' && answer.toLowerCase() !== 'yes') {
            console.log('❌ Abgebrochen.\n');
            await sequelize.close();
            process.exit(0);
        }

        console.log('\n🧹 Starte Vacuum...\n');

        // Führe VACUUM ANALYZE aus
        for (let i = 0; i < tablesToVacuum.length; i++) {
            const table = tablesToVacuum[i];
            const startTime = Date.now();
            
            try {
                console.log(`[${i + 1}/${tablesToVacuum.length}] Vacuuming ${table.table_name}...`);
                
                await sequelize.query(`VACUUM ANALYZE ${table.table_name};`);
                
                const duration = ((Date.now() - startTime) / 1000).toFixed(2);
                console.log(`   ✅ Fertig in ${duration}s\n`);
            } catch (error) {
                console.error(`   ❌ Fehler: ${error.message}\n`);
            }
        }

        console.log('='.repeat(60));
        console.log('✅ Vacuum abgeschlossen\n');

        await sequelize.close();
        process.exit(0);

    } catch (error) {
        console.error('❌ Fehler:', error.message);
        console.error(error.stack);
        process.exit(1);
    }
}

main();