#!/usr/bin/env node

/**
 * Script zum Erstellen von Performance-Indizes
 * 
 * Erstellt Indizes basierend auf der Analyse häufiger Queries:
 * - inventory: stock_id
 * - stock: branch_id
 * - production: branch_id
 * - director: employer_user_id
 * - knowledge: (character_id, product_id) composite
 */

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

async function main() {
    try {
        console.log('🔧 Erstelle Performance-Indizes\n');
        console.log('='.repeat(60) + '\n');

        const indexes = [
            {
                name: 'idx_knowledge_character_product',
                table: 'falukant_data.knowledge',
                columns: '(character_id, product_id)',
                description: 'Composite Index für JOINs mit character_id UND product_id',
                critical: true
            },
            {
                name: 'idx_inventory_stock_id',
                table: 'falukant_data.inventory',
                columns: '(stock_id)',
                description: 'Index für WHERE inventory.stock_id = ...',
                critical: true
            },
            {
                name: 'idx_stock_branch_id',
                table: 'falukant_data.stock',
                columns: '(branch_id)',
                description: 'Index für WHERE stock.branch_id = ...',
                critical: true
            },
            {
                name: 'idx_production_branch_id',
                table: 'falukant_data.production',
                columns: '(branch_id)',
                description: 'Index für WHERE production.branch_id = ...',
                critical: true
            },
            {
                name: 'idx_director_employer_user_id',
                table: 'falukant_data.director',
                columns: '(employer_user_id)',
                description: 'Index für WHERE director.employer_user_id = ...',
                critical: true
            },
            {
                name: 'idx_production_start_timestamp',
                table: 'falukant_data.production',
                columns: '(start_timestamp)',
                description: 'Index für WHERE production.start_timestamp <= ...',
                critical: false
            },
            {
                name: 'idx_director_last_salary_payout',
                table: 'falukant_data.director',
                columns: '(last_salary_payout)',
                description: 'Index für WHERE director.last_salary_payout < ...',
                critical: false
            }
        ];

        console.log(`📋 ${indexes.length} Indizes werden erstellt:\n`);

        let created = 0;
        let skipped = 0;
        let errors = 0;

        for (let i = 0; i < indexes.length; i++) {
            const idx = indexes[i];
            const criticalMark = idx.critical ? ' ⚠️  KRITISCH' : '';
            
            console.log(`[${i + 1}/${indexes.length}] ${idx.name}${criticalMark}`);
            console.log(`   Tabelle: ${idx.table}`);
            console.log(`   Spalten: ${idx.columns}`);
            console.log(`   Beschreibung: ${idx.description}`);

            try {
                // Prüfe ob Index bereits existiert
                const [existing] = await sequelize.query(`
                    SELECT EXISTS(
                        SELECT 1 FROM pg_indexes 
                        WHERE schemaname || '.' || tablename = '${idx.table}'
                        AND indexname = '${idx.name}'
                    ) as exists;
                `);

                if (existing[0].exists) {
                    console.log(`   ⏭️  Index existiert bereits, überspringe\n`);
                    skipped++;
                    continue;
                }

                // Erstelle Index
                const startTime = Date.now();
                await sequelize.query(`
                    CREATE INDEX IF NOT EXISTS ${idx.name}
                    ON ${idx.table} USING btree ${idx.columns};
                `);
                
                const duration = ((Date.now() - startTime) / 1000).toFixed(2);
                console.log(`   ✅ Erstellt in ${duration}s\n`);
                created++;

            } catch (error) {
                console.error(`   ❌ Fehler: ${error.message}\n`);
                errors++;
            }
        }

        console.log('='.repeat(60));
        console.log(`✅ Zusammenfassung:`);
        console.log(`   Erstellt: ${created}`);
        console.log(`   Übersprungen: ${skipped}`);
        console.log(`   Fehler: ${errors}\n`);

        // ANALYZE ausführen, damit PostgreSQL die neuen Indizes berücksichtigt
        const tablesToAnalyze = [
            'falukant_data.knowledge',
            'falukant_data.inventory',
            'falukant_data.stock',
            'falukant_data.production',
            'falukant_data.director'
        ];
        if (created > 0) {
            console.log('📊 Führe ANALYZE auf betroffenen Tabellen aus...\n');
            for (const table of tablesToAnalyze) {
                try {
                    await sequelize.query(`ANALYZE ${table};`);
                    console.log(`   ✅ ANALYZE ${table};`);
                } catch (err) {
                    console.log(`   ⚠️  ${table}: ${err.message}`);
                }
            }
            console.log('');
        }

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

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

main();