/**
 * Migration 026: Fuzzy search with trigram similarity (pg_trgm)
 *
 * - Enables pg_trgm extension for Levenshtein-like fuzzy matching
 * - Creates GIN indexes on product name/description for fast trigram similarity
 * - Adds similarity index on brands and categories for term suggestions
 *
 * Run: node migrations/026_fuzzy_search.js
 */

const { Pool } = require('pg');

const pool = new Pool({
  connectionString: process.env.DATABASE_URL || 'postgres://mdv:mdv_dev_only@localhost:5432/mercadodevida',
});

async function migrate() {
  const client = await pool.connect();

  try {
    await client.query('BEGIN');

    // 1. Enable pg_trgm extension
    await client.query(`
      CREATE EXTENSION IF NOT EXISTS pg_trgm;
    `);
    console.log('✓ pg_trgm extension enabled');

    // 2. GIN index on product name for trigram similarity
    await client.query(`
      CREATE INDEX IF NOT EXISTS catalog_products_name_trgm_idx
      ON catalog_products
      USING GIN (name gin_trgm_ops);
    `);
    console.log('✓ catalog_products name trigram index');

    // 3. GIN index on product description
    await client.query(`
      CREATE INDEX IF NOT EXISTS catalog_products_description_trgm_idx
      ON catalog_products
      USING GIN (description gin_trgm_ops);
    `);
    console.log('✓ catalog_products description trigram index');

    // 4. GIN index on brand names (for suggestions)
    await client.query(`
      CREATE INDEX IF NOT EXISTS brands_brands_name_trgm_idx
      ON brands_brands
      USING GIN (name gin_trgm_ops);
    `);
    console.log('✓ brands_brands name trigram index');

    // 5. GIN index on category names (for suggestions)
    await client.query(`
      CREATE INDEX IF NOT EXISTS categories_categories_name_trgm_idx
      ON categories_categories
      USING GIN (name gin_trgm_ops);
    `);
    console.log('✓ categories_categories name trigram index');

    // 6. Record migration
    await client.query(`
      INSERT INTO pgmigrations (name, run_on)
      VALUES ('026_fuzzy_search', NOW())
      ON CONFLICT (name) DO NOTHING;
    `);
    console.log('✓ Migration recorded');

    await client.query('COMMIT');
    console.log('\n✅ Migration 026 complete: fuzzy search indexes created');
  } catch (err) {
    await client.query('ROLLBACK');
    throw err;
  } finally {
    client.release();
    await pool.end();
  }
}

migrate().catch((err) => {
  console.error('❌ Migration failed:', err.message);
  process.exit(1);
});