const Database = require('better-sqlite3');
const fs = require('fs');
const path = require('path');
require('dotenv').config();

const dbFile = process.env.DATABASE_FILE || 'database.sqlite';
const dbPath = path.isAbsolute(dbFile) ? dbFile : path.join(__dirname, dbFile);

let db;
try {
  // better-sqlite3 creates the database file synchronously on creation
  db = new Database(dbPath);
  console.log(`📂 SQLite database connected via better-sqlite3: ${dbPath}`);
} catch (err) {
  console.error('💥 Failed to open SQLite database:', err.message);
  process.exit(1);
}

// Wrap operations in async functions to maintain compatibility with server.js
async function query(sql, params = []) {
  const stmt = db.prepare(sql);
  const trimmedSql = sql.trim().toUpperCase();
  const isMutating = trimmedSql.startsWith('INSERT') || 
                     trimmedSql.startsWith('UPDATE') || 
                     trimmedSql.startsWith('DELETE');

  if (isMutating) {
    const result = stmt.run(params);
    return { insertId: result.lastInsertRowid, changes: result.changes };
  } else {
    return stmt.all(params);
  }
}

async function initializeSchema() {
  try {
    const schemaPath = path.join(__dirname, 'schema.sql');
    if (fs.existsSync(schemaPath)) {
      const sql = fs.readFileSync(schemaPath, 'utf8');
      // Executes multiple SQL statements in schema.sql
      db.exec(sql);
      try {
        db.exec('ALTER TABLE requests ADD COLUMN tipo_solicitud TEXT;');
        console.log('➕ Added tipo_solicitud column to existing requests table');
      } catch (e) {
        // Ignore if column already exists
      }
      console.log('✅ Database schema initialized/verified successfully');
    }
  } catch (error) {
    console.error('⚠️ Failed to initialize schema automatically:', error.message);
  }
}

module.exports = {
  query,
  initializeSchema,
  db
};